Earth viewed from the International Space Station |
The 'Jules Verne' ATV Space supply ship for the international space station prepares for launch.February 2008
Propellant will be loaded on board Jules Verne: around 2 200 kg of MMH (Monomethylhydrazine) and 3 600 kg MON3 (Mixed Oxides of Nitrogen) propellant which will be used by ATV’s own propulsion system.
ATV will use these propellants for its autonomous navigation towards the International Space Station (ISS) and, once docked, to contribute to the Station's attitude and orbit control, including re-boost of the whole space complex. Already around 860 kg of nitrogen tetroxide oxidiser (N2O4) and Russian produced UDMH (Unsymmetrical dimehtylhydrazine) have been stored on board ATV
With the amount of propellant in ATV about to exceed 4 tonnes, the safety rules at the Spaceport prohibit working on other satellites or spacecraft within the perimeter of the S5 integration building.
"In the first week of February, Jules Verne ATV – filled with a total 6.5 tonnes of four different propellants and 20 kg of oxygen – will be moved to the Final Assembly Building [BAF - Batiment d’Assemblage Final] where it will be mated to the Ariane 5 launcher. We then enter the Ariane 5/ATV 'combined operations plan', which ends with the final countdown," explains Nicolas Chamussy, ATV Programme Manager for EADS Astrium.
The whole Jules Verne ATV weighs 19.4 tonnes, including approximately 1 338 kg of ‘dry cargo’. During fuelling and oxygen operations, the ATV is electrically completely shut down for safety reasons. Each day the whole spacecraft is activated to check the spacecraft’s ‘health’, and charge the batteries once again
Once in orbit, the 20 kg of oxygen carried up by Jules Verne ATV, is manually injected by the crew into the ISS atmosphere. For up to six months, the ATV remains attached, mostly in dormant mode with the hatch to the ISS open.
With the ATV docked, the Station crew can enter the cargo section and remove the payload: supplies, science hardware, and lightweight luggage bags. Meanwhile, the ATV's liquid tanks are connected to the Station's own plumbing and their propellant contents discharged.
According to the needs of the ISS and its partners, the ATV remains an
integral Station element for up to six months, and delivers dry cargo,
fuel, water and oxygen to the ISS.
Exoplanet Gliese 581c discovered 24th April 2007
The closest found to date at only 20.5 lights years from Earth in the constellation Libra (balance)
This exoplanet is orbiting around its sun or star which is known as a red dwarf .
esa Launch Archive Data
Stop Press News Release
18th January 2007 The first Soyuz launched in 2007 from Baikonur carried the “Progress M59” cargo module for the International Space Station. M59 has been dedicated with the name of the Ukranian spacecraft designer Sergei Korolev. To mark the centenary of his birth
2007 marks the:
Message from a 'Zek' In honour to those lost along the way.
It has taken us 50 years to understand what Korolev and his team achieved.
'Now the way to the stars is open.......'
Thanks to a
engineer who suffered six years of repression under the Satlin purges and
an unknown teacher from Kaluga. Who worked in isolation for forty years to
identify the physics of how to escape from Earth and explore the
Eleven days at the International Space Station for just 25.106 US dollars!
Dr. Charles Simonyi one of the original software developers at Microsoft blasts into space. 7th April 2007
The Soyuz TMA-10 spacecraft containing Simonyi and two Russion cosmonautes Fyodor Yurchikhin and Oleg Kotov. lifted off from the Kazakh steppe ar11.31pm local time.
Live coverage and the story of Charles Simonyi's preparation can be found on
Earth's ecllipse of the full moon 5th March.
image courtesy esa
As the Earth passes between the sun and the moon it casts its shadow over the surface of the moon.
Stephen Hawking awarded Royal Society's Copley Medal
1st Dec 2006 After being honoured with the prestigous Royal Society's Copley Medal Stephen Hawking re-emphasised Tsiolkovki's objective of encouraging human exploration of space to discover other planets where human life can be supported in order to guaranrtee the survival of life as we know it in the future. The threats to life on Earth from asteroids and long term pollution are real.
MetOp satellite launch
Soyouz MetOp satellite launch 19th October From Baïkonour (Kazakhstan)
Animation of MetOp launch and satellite seperation
Smart 1 The final touchdown.
Smart1 esa video
30th August 2006 esa SMART 1 satellite is due to impact the moon surface on the morning of the 3rd September after completing its extended mission.
SMART-1's impact is currently expected on 3 September 2006 at 07:41 CEST (05:41:51 UT), in the point located at 46.2º West longitude and 33.3º South latitude.
12th August 2006 heavy lift version of Ariane5 successfully launched two satellites the Japanese CSAT-10 and SYRACUSE 3B for the French military.
11th March 2006 V170 Ariane 5ECA successfully launched the satellite payload SPAINSAT & HOT BIRD
Specification of Ariane 5 ECA rocket
Giove A transmits its first navigation data signal 4th May 2007
What is GioveA ?
The mission objectives of the two satellites GIOVE-A and GIOVE-B fulfills a number of objectives.
1. To secure use of the frequencies allocated by the International Telecommunications Union (ITU) for the Galileo system.
2. To verify the most critical technologies of the operational Galileo system, such as the on-board atomic clocks and the navigation signal generator.
3. To characterise the novel features of the Galileo signal design, including the verification of user receivers and their resistance to interference and multipath.
Last but not least, it will characterise the radiation environment of the Medium Earth Orbit planned for the Galileo constellation.
GIOVE-A and -B are being built in parallel to provide in-orbit redundancy and secure the mission objectives. They provide complementary capabilities.
GIOVE A Launched 28th December 2006 from Baikonur, Kazakhstan using the Starsem Soyuz Fregat
Giove A, the first Galileo in-orbit validation element, was launched today from Baikonur, Kazakhstan, atop a Soyuz-Fregat vehicle operated by Starsem. Following a textbook lift-off at 05:19 UTC (06:19 CET), the Fregat upper stage performed a series of manoeuvres to reach a circular orbit at an altitude of 23 258 km, inclined at 56 degrees to the Equator, before safely deploying the satellite at 09:01:39 UTC (10:01:39 CET).
21 December 23.33 CET (Central European Time) Ariane 5G successfully launched two satellites Indian communications INSAT 4A 3100kgs and European second generation meterological MSG 2 2034Kgs. As a comparison the joint satellised mass of 6390Kgs launched 21.12.05 is 3.8 times that satellised by Ariane 1 24 years earlier.
27th May2006 Ariane 5 ECA sets new record as a two satellite mission with a mass of 8300kgs is successfully launched and placed into a geostationary transfer orbit .
16th November successful launch of esa Arianespace Ariane5 ECA with a record breaking heavy lift 8000kgs two satellite charge.
Latest esa launch
Venus Express, launched in November 2005, will enter Venusian orbit next week on 11 April, after a 153-day cruise to the planet. The design of Venus Express is a follow on from the Mars Express spacecraft and many of its instruments belong to the heritage of the Mars Express and Rosetta platforms.
esa Venus probe launch 9 November launch using Soyuz Fregate R7.From Baïkonour (Kazakhstan)
Taking no more than three years to design and build Venus Express uses technology and experience used for the Mars Express mission. Flight distance to Venus approximately 400 million kms.
Satellite mass m3 =1270Kgs
The1703 mission for the R7 launch vehicle.
Do we want planet earth to become like its sister planet Venus? Surrounded by an atmosphere of carbon dioxide and acid rainfall. We are still trying to understand why our sister planet is so different.
Venus express infa rouge image of south pole of Venus 12.4.2006
Successful Venus Express main engine firirng 17.2.2006
The 3 second engine burn increased the space probe velocity by 3m/sec.
Venus Express is currently 47 million kms from Earth.
Venus Express joined by Nasa Messanger probe as it flies by Venus Jne 2007
168 The launch of Flight 168, an Ariane 5G with a dual payload, will take place
on 13 October 2005 from Europe's Spaceport in French Guiana
Ariane 5 ECA Heavy lift version of Ariane 5.Launch video
China launches 5 day two man space mission. Shenzhou
12 th October 2005 01.00hr GMT.
The Shenzhou VI spacecraft blasted off on top of a Long March 2F rocket from the Jiuquan Satellite Launch Centre in north-west China at 0900 local time (0100 GMT) and entered orbit 21 minutes later.
China successfully launched the two "taikonauts" Fei Junlong and Nie Haisheng into orbit, marking the country’s second crewed foray into space. Observers say the milestone signals China's commitment to a human spaceflight programme.
China's first crewed spaceflight in the Shenzhou V in October 2003.Yang Liwei was chosen to pilot that mission, which made China the third country after the US and the former Soviet Union to send a human into space.
Click image for launch film
In the history of the development of astronautics in China, Tsien Hsue-shen plays a fundamental role equivalent to that of Korolev in the birth of Soviet space rocket.
|Last launch of Ariane 4|
We have selected a video of the last 'Ariane 44L' V159 launched from Kourou on 15th February 2003.This section covers the first 2 mins of the flight from launch to booster seperation.
Just click on the image and load the video
To carry out your own research and find launch archive videos.
Follow the link sequence:
Note:If the sound or picture quality is not right then
reset the video setting and try again.
To understand more about the programme preparation phase look at the 'Launch Kit" document
Page5 shows the rocket trajectory to place a satellite in orbit.
The different stages of the 'Ariane44L' rocket are clearly illustrated on page6.
To find details on other rocket launches follow the steps below:
go to www.arianespace.com then click on the News tab, select "Launch Kit" and select the flight number .
The history of Ariane
Comparison of Ariane 1,2 and 3
Development of Ariane 4
The objective of this section is to help you find rocket launch information easily.
Starsem esa Soyuz Fregate
Soyuz has been launched > total 1729
Soyuz Fregate: the R7 descendent launcher used for launching esa Mars Express and the 'Beagle2' Mars lander June2003
First Stage Comprised of 4 Glushko conical RD107 engines surrounding a cental core RD108 rocket engine. Both use keresene and oxygen
The conical RD107 engines seperate after the first 2 minutes of flight ,once all the fuel has been used; leaving the central RD108 to complete a second stage burn.
The third stage can be seen above the seperation structure that appears to be transparent.
The final or fourth stage Fregate is capable of multiple starts and is used to manouver the payload capsule into the desired orbit. This can be identified as the part in the nose of the rocket with a series of six red balls that contain fuel and instruments at its base.
For more detail refer to esa Mars Express launcher.
Manufacturers of Russian 'Soyuz' site
Soyuz launcher modules.
R7 Soyuz Fregate launch vehicle specification
Fantastic launch video of the Soyuz Fregate Galaxy mission.
Courtesy Starsem esa
Soyuz Fregate launch video of the Galaxy14 mission.Fantastic video sequence showing night launch and the first and second stage seperation.
Duration 9 mins. First stage seperation 3.52mins video synch. High atmospheric plume due to low external pressure outside the motor expansion nozzle 5.2mins.
1 October 2005 Soyuz Launch crew to the International Space Station.
For kean enthusiasts look at the full length video 49min duration of launch preparation and launch at 34mins to be found at the S.P Korolev Rocket and Space Corporation Energia site.
The 'Blue Streak' nuclear launcher was very similar to the USA 'Atlas' rocket programme. Both the 'Black Night' and 'Black Arrow' rockets played a major part in the development of the Blue Streak project.
Although the 'Blue Streak' project was a strategically flawed compromise.
Having a medium range, liquid propergol fueled launcher as an operational weapon on British soil would have made the UK the first priority for a Russian nuclesr strike.
During the seven minutes that it would have taken to fuel and fire the missile. The UK would have been wiped off the map by Russian missiles. That had solid propergols and would have taken 4 minutes to land on selected strategic sites.
Whilst a submarine based Polaris launch system would be difficult to neutralise.
Other applications for this technology only became apparent following the the successful launch of the Russian satellite Sputnik by the USSR on 4th October 1957.
Start of the UK Polaris submarine detterent strategy
Black Arrow.( The flying lipstick )
Three stage rocket hydrogen peroxide H2O2 and kerosene fueled 1st and 2nd stages with solid propergol 3rd.
M2= 73Kgs Prospero satellite
Ft = 222KN
m1= 14100 Kgs d1 = 1.98m Ft = 222 KN t =125s
m2= 3500 Kgs d2 = 1.38m Ft = 69 KN t = 120s
m3= 500 Kgs d3 = 0.71m Ft = 21 KN t = 40s
It is not well known that after the second world war teams of German engineers that had previuosly worked on the V2 programme where also absorbed into the development of both the Black Night and Viking rocket engines.
The Black Night and Black Arrow launcher development subsequently contributed to the european ELDO 'Europa 1, Europa 2' and esa Ariane ( Europa 3) programmes.
Although the Britsh satellite launcher programmes where effectively strangled by inadequate development funding and a complete lack of political support.
Black Arrow successfully launched Britains first and only satellite ' Prospero' on 28 October 1971. Black Arrow engineers had only been given permission for three launches and succeeded in launching a satellite.
Whilst the joint European Europa 1 project had nine attempts and failed .
Principly due to the lack of experience of the French and German engineers with developing 2nd and 3rd stage modules to the level of systems reliability required.
Profiting from the experience gained with Black Arrow the first stage functioned well.
The multi national engineering team needed time to fuse into a cohesive European unit, that could descend the learning curve! By learning from experience and analysing the reasons for failure.
Good background information can be found on the Science Museum site
It didn't get to the Moon. It didn't even get into Earth orbit. But it was the most successful British space rocket, and it has been launched for the last time.
Hardly anyone outside the scientific community has ever heard of Skylark, designed by British engineers to send experiments far above the Earth, yet it has been shooting upwards for 48 years. The final launch, from the Swedish Space Corporation's Esrange site near Kiruna in the remote north of the country, early yesterday morning, was the 441st.
Question: Which rocket contributed more to science the Space Shuttle or Skylark
In terms of prestige
In terms of cost.
Note: Sounding rockets are usually used to launch scientific payloads to an apogee of 250kms. To sample the earths atmosphere or expose payload experiments to a period of near zero gravity 1*10-4g .
Initially sounding rockets where used to record rocket flight dynamics and understand the physical nature of of the outer atmosphere. So that larger rockets could be developed to place man made satellites in orbit.
The USA Atlas rocket
Karel Jan Bossart(1904-1975) from Belgium was the father of the Atlas rocket . Initially used as an intercontinental ballistic missle and later used for the USA manned Mercury missions.
His principle innovations where to integrate the increased strength and stiffness of an inflated main struture module. To increase the overall strength of the rocket structure and reduce its launch mass.M1 This was achieved by pressirising the thin stainless steel main structure module using pressurisedheliumgasatbetween2>4 bar. Effectively reducing the structure mass to only 2% of the propellant fuel mass at lift off. Although the structure was light it was capable of absorbing high structural loads.
Maybe this is what inspired some old Atlas rocket engineers to use a pressurised plastic drinks bottle. when thay began to replace the conventional glass coke bottles in 1977.
Use gimballed rocket engines that when controlled by hydraulic actuators could provide variable direction and rocket thrust.
At the same time Werhner von Braun Redstone programme was using V2 technology of varaible control surfaces (external fins ) and graphite vanes in the rocket exhaust stream.
Prototype NASA X 43A SC.RAM Jet
Could this be the start of an new era for more effecient jet propulsion ?
NASA X 43A air breathing, hydrogen fueled prototype achieves Mach 7
Length L = 4m
Width W = 1.5m
Mass M1 = 981 kgs
Tvol = 11secs
Attained Mach 7. 2252 m/s
Objective Mach 10. 3218 m/s.
An earlier attempt in June 2001 ended in failure. When the booster rocket used to accelerate
the X-43 prototype up to the velocity required for the 'SCRAM' jet to function .Went out of control and had to be destroyed. Causing the echec of the first flight trial of the X 43.
The 'scram jet' relies on air entering the intake at supersonic velocity to rapidly compress the air charge. Before the hydrogen is added. This ram air replaces the oxygen usually used in conventional rocket jet combustion.
The advantage would be that if this type of Scram jet could be made to work by accelerating a payload from Mach5 to Mach15 whilst the hypersonic launcher was still in the Earths atmosphere. Then the large mass and volume of the oxygen currently required to burn the carburant or propergol in a standard launcher system. Would no longer be required.
The real technological problem is that currently like expansion nozzles on existing launchers the ideal duct and nozzle geometry required by the SCRAM jet needs to change with altitude to maintain combustion efficiency .Currently the Superstao SCRAM is a fixed geometry device.
Thermal shock loading at increaseed velocity creates a major problem for material scientists toovercome duringthetransitionMach7>Mach15
Following the failure of the first flight trial. A lot was learned by the team of engineers and scientists involved. Clear identification and analysis of the causes.
Leading to the current success.
A cheaper more efficient means of accessing space in the future.
November16th 2004 Third flight reaches Mach 9.6
Satellite orbits required for :
New esa site to access satellite images in near real time
Water monitoring satellite
Monitoring one of Earths most valuable resources the esa SMOS satellite programme will monitor the soil humidity and ocean salinity.
Click on the link below to watch the video. Once linked click on sound tab in the top right hand of the screen
Envisat monitoring water temperature and plankton blooms in our oceans.
This amazing image from the Envisat satellite shows the plankton bloom in the eastern Altantic ocean just off the Irish coast, The massive light blue band indicates the area occupied by plankton.
Envisat recording the water temperature distribution in the Mediteranean sea around the Baleric Islands
|Click to see view of Earth fromm ISS
The International Space Station (ISS) is about to have the European space laboratory module 'Colombus' added.
ISS has a velocity of 7.7Km/sec at an orbit of 390 Kms
Soyuz is the principle launcher for sending astronautes and supplies. Whilst the Proton and Nasa shuttle are used to lift the large modules from which the space station is built.
How old is the ISS ?
In Nov 1998 a Russian Proton rocket , launched from Baikonur, satellised the first ISS 'Zarya' module.
Since then the Space station has been progressively extended.
The ISS build programme was frozen following the loss of shuttle Columbia and its seven crew on February 1st 2003 during re-entry.
June 2007 A multiple on board navigational computer failure causes concern among mission engineers.
The cause of the multiple computer failure is currently under review to establish whether thiis could affet the ATv mission that is equiped with the same computer system to help the automatic docking procedure.
It is thought that some external system or work on updating the ISShas created the power surge that caused the computers to crash. Another possibility coulsd be solar radiation storms,
esa Automatic Transfer Vehicle 'Jules Verne'
This supply spaceship will be used to supply fuel and supplies to the ISS .
The ATV will also supply DV or boost energy to the International Space Station to maintain its required orbit
To see what the Earth looks like from ISS click on the image above
How to find the ISS or other satellites in the night sky use
Galileo Test satellite for European GPS satellite network.
The GPS system 'Galileo' is made up from a network of 30 satellites that will give the European government an independent high accuracy GPS system for civil and miiltary defense use. Scheduled to be fully operational in 2008.
Test satellite launch
SMART 1 Moon mission 2004/2005. Smart1 is the esa satellite probe being used to develop and prove a new electric ion propulsion motor. That could be used for future inter planetary missions.
In total the solar electric ' ion jet' propulsion unit has functioned for 3700hrs during its 84 million kms spiralling flight around Earth and then the moon . Equivalent to an inter planetary flight.
Note: SMART Stands for Small mission for the research into advanced technology.
SMART-1 accomplished 332 orbits around Earth before heading out towards the moon. It fired its engine 289 times during the cruise phase, operating for a total of about 3700 hours. Only 59 kilograms of xenon propellant were used (out of 82 kilograms). Solar energy is used to generate the ion stream which produces the thrust.
Overall, the engine performed extremely well, enabling the spacecraft to reach the Moon two months earlier than expected.
The extra fuel allowing the moon flight programme to be revised and extended by one year.
With more fuel in reserve the Smart1 probe flight plan has been modified to achieve an elliptic orbit that brings it closer the moons surface.
SMART 1 ion engine performance assessment.esa
The Spiral trajectory of SMART1
First image of the Moon recorded by SMART 1 January 2005
3rd September 2006
esa SMART 1 satellite is due to impact the moon surface after completing its extended mission
SMART-1's impact is currently expected on 3 September 2006 at 07:41 CEST (05:41:51 UT), in the point located at 46.2º West longitude and 33.3º South latitude.
Smart 1 The final touchdown.
Good esa video on SMART1 moon mission
JPL History Site
JPL Jet Propulsion Laboratory history site covers the history of all the famous space probes and satellites.
Good visually and well presented
Why use electric propulsion
For further information follow the links to esa
The magic of ion engines
Ion Space jet propulsion.
Charged atoms of xenon are acclerated then neutralised by an electron canon to create a ion jet stream.
The xeon ions are currently capable of being accelerated to betwwen 15 and 30 Km/sec which is six times the gas ejection velocity of a current rocket engine.
That's the good news . However when we then look at the mass flow rate achieved by the ion engine it is currently 10-7 times inferior to that of an existing rocket propulsion system.
So it can only be used in outer space in a near vacuum with the electrical energy needed to create the ion stream generated by banks of solar cells or a small nuclear reactor.
The principle advantage of the ion motor linked to solar cells is that its range is not limited by the need to carry large volumes of propergols to create a chemical combustion. But simply the volume and size of xenon reservoir which is possible to include within the spacecraft. There also needs to be some form of radiated energy such as light that can be collected and converted into electrical energy.
So although the ion motor has a low mass flow rate it can last for considerably longer.
Note:To voyage between solar systems where the availability of light energy is insufficient then some other form of energy will need to be collected to create the electron stream.
Currently this is overcome by installing a small nuclear reactor into the satellite. Although this causes interference and degrades the satellites operating life.
Alternatively this could be replaced if either solar sails or other forms of radiated energy can be efficiently converted into electrical energy
NASA engineers are currently working on a Vasimir which uses a magnetic plasma impulsion system to generate a gas stream of 300km./sec or one thousandth 1*10-3 the speed of light.
Why Xenon ?
Xenon is an inert gas with a high molecular mass when compared to hydrigen. Efficient Propulsion is always related to mass flow and impulse.
Xenon > Xe Atomic No.54 Atomic Mass131.3
Hydrogen > H 1 1.01
The Smart1 craft developed a DV of 3.5Km/sec. using a combination of ion propulsion and using low gravity Lagrange orbits ( Gravitational equilibrium points that exist between two planets.) .
accelerates towards a new electric
plasma propulsion system
The Helicon plasma propulsion concept is an ingenious one, inspired by the northern and southern aurorae, the glows in the sky that signal increased solar activity.
What is a plasma..
Plasma can be thought of as the fourth state of matter. Just as solids, liquids and gases have different properties, so too does plasma. It is a gas in which the atoms have been stripped of some of their electrons, meaning that they react more readily to changes in the electric and magnetic fields to which they are exposed. It is estimated the 99% of the matter in the Universe is plasma. On Earth, however, naturally occurring plasma is rare, apart from within the layer of the atmosphere called the ionosphere
|Jan 2006 esa Sponsored research in Australia yields new
ion engine development the Dual-Stage 4-Grid (DS4G)
The DS4G ion engine uses a concept first proposed in 2001 by David Fearn, a pioneer of ion propulsion in the UK, which overcomes the problems of accelerated ions impacting the high voltage grid plates used to accelerate the ion beam.Thiscurrently limits the efficiency of traditional ion propulsion jets. To overcome this a two-stage process to decouple the extraction and acceleration of ions using four grids is used In the first stage, the first two grids are closely spaced and both are operated at very high voltage and a low voltage difference between the two (3 kV) enables the ions to be safely extracted from the chamber without hitting the grids. Then, in the second stage, two more grids are positioned at a greater distance ‘downstream’ and operated at low voltages. The high voltage difference between the two pairs of grids powerfully accelerates the extracted ions.
The test model achieved voltage differences as
high as 30kV and produced an ion exhaust plume that travelled at 210,000
m/s (210km/sec) , over four times faster than state-of-the-art ion engine
designs achieve. This makes it four times more fuel efficient, and also
enables an engine design which is many times more compact than present
thrusters, allowing the design to be scaled up in size to operate at high
power and thrust. Due to the very high acceleration, the ion exhaust plume
was very narrow, diverging by only 3 degrees, which is five times narrower
than present systems. This reduces the fuel needed to correct the
orientation of spacecraft from small uncertainties in the thrust
MIT Space propulsion lab
The history of electric propulsion
Solar cells absorb light to produce electrical energy.
Below is a solar cell used to drive a minature electric motor used to power a small toy car.
In sunlight it has a velocity of 0.86m/sec
Dependent on the type and efficiency of the solar cell used. The surface area of solar cells required to power a larger car or a satellite can be calculated..
There are currently several types of solar cell. Most based on silicon crystal material of differing structures.
The photovoltaic or solar cell is based on semicnductor materials that normally are insulators but when exposed to light become either capable of carrying positive p or negative charge carrying n materials. If you then create an interface or junction between these materials you can create a voltage difference between them that is dependent on the light energy to which each material is exposed in W/m2.
Those based on different types silicon crystal semiconductor are the most common. Pure silicon crystals produce the most efficent solar cells with a theoretical efficiency of 23 to 28%.
Inefficiency is due to light energy not being fully absorbed or being tranformed into other forms of energy such as heat.
The silicon is doped or seeded with a specfic impurity to give it its positive or negative charge carrying characteristic
Other alternative material combinations such as gallium arsenide, copper indium diselenide and cadmium telluride are used to capture different frequancy bands and energy levels of photons.
To overcome some of the ineffiuciencies encountered with single layer solar cell pairs, for space and satellite applications. muliple layers of solar cells of different types have been developed to capture a larger band width of photons and improve energy conversion. Important parameters are the solar cell mass Kgs/m2, overall life cost per Kg launched into orbit and the efficiency for energy conversion from light energy exposure in W/m2 to KW of electricty produced
The lightweight 'Nuna 2' solar car completed the 3010 kms between Darwin and Adelaide in the Australian 'World Solar Challenge' with an average velocity of 92Km/hr. Having a potential top speed of 160Km/hr.
The solar cells used are the same as those used on the Smart1 satellite that had been donated to the Dutch Delft university team as part of a esa space technology transfer scheme.
Initially Smart1 could supply1190W but with time the power output from the solar cells will decay due to space impact damage and thermal shock ageing of the materials.
Address: Third rock from the Sun.
'Our future survival depends on whether we can colonise distant planets orbiting far-away stars.'Stephen Hawkins
you want to go to 'Mars'
Detail of an image taken during the polar orbit of the Mars Express satellite of what ressembles a dry river bed at the bottom of a canyon.
22.1.2004.Mars Express discovers the presence of water in the form of ice at the southern polar cap on a Mars. The presence of quantities of water and methane was also detected using a technique called spectral analysis. That looks at the different wavelengths of light transmited by the mixture of frozen liquids that make up the polar cap on Mars.
Similar spectral analysis is carried out on the mixture of gases contained in the atmosphere of Mars to identify the basic elements and gases from which it is made.
There is a unique wave length for each colour of light found in the transmitted light spectrum (or rainbow) ranging from red to blue . Because there is a known absorption signature for every gas and element. Black bands appear in the spectral analysis recorded where this gas is present.
Different molecules absorb different wavelengths related to specific colors, producing a barcode like series of black lines across the visible rainbow spectrum.
4.12.2004. A three year study by Dr Michael Mumma NASA of the presence of methane in the atmosphere of Mars. Has concluded in a report which says that the origin for methane could be proof of the presence of some form of microbial life on Mars. Methane is a relatively fragile gas and is easily broken down by ultra violet radiation from the sun.
In March 2004 scientists from the esa Mars Express mission reported that they had identified variations in the methane levels in the atmosphere of Mars that corresponded to the known levels of frozen water contained below the surface. Indicating that there could be some form of microbial life living in the water trapped below the surface producing the methane.
30th Nov2005 esa publish findings From Titan and Mars missions.
Nasa MER Jet Propulsion Lab mission to Mars.
Success. Well not always.
Over 60% of all the international space probes sent to Mars have failed. These are invariably the ones you never hear about.
But it is just as important to understand why something has failed As it is to fully appreciate why a project is successful or did not fail.
Is there life on Mars Nova program Is Mars dead or alive
Nova programme on the visit to Saturn planet Titan
Images Hubble Nasa esa
Why is space exploration important.
Most of the exploration of our universe. Is to discover more about our solar system and beyond.
So we can understand more about our own world and its environment.
|16th August 2006
Well sought off.!
Following a redefinition of how a planet is defined. Astrophysicts have reduced the number of planets in our solar system to eight with Pluto relegated along with Ceres, Charon and US313 which will all be given the new status of 'Plutons'.
|It was twenty years ago today...
'Giotto' the Halley comet chaser satellite.2nd July1985.
On the night of 13 March 1986 the Giotto spacecraft passed within 600km of the core of comet 1P/Halley. Launched eight months earlier on 2 July 1985, Giotto was the first spacecraft to visit a comet's nucleus and represented ESA's first deep space mission.
Progamming the flight trajectory of 'Giotto' to coincide with the comet was a major achievement.
As Giotto approached the center of the comet it was hit by a particle weighing only 0.1gms but with a velocity of 68Km/s that temporarlly destabilised its flight orientation and caused it to wobble. Fortunatley this stabilsed and the probe continued its mission.
Comet Halley visits our solar system once every lifetime (76years) and is due to visit our skies next in 2062.and was featured in a painting by Florentine painter Giotto in1304. Inspired by the visit of Halleys comet in 1301. The red ball with a tail represtenting comet can be identified above the stable at the top of the image.
esa video of the Giotto mission
esa science videos index
Select Giotto 20 years
|Space debris video|
Impact site diameter 3.5mm with a pierced hole 0.5mmdia
The effect of hyper-velocity space impacts on spacecraft and space probes like Giotto. Can be life threatening. Impacts of even small particles at velocities in excess of 4-5Kms/sec can be devestating to any space structure.
Even worse if it is a manned spacecraft or the spacesuit of an astronaut on an external EVA.
Typical impact velocities encountered by orbiting spacecraft are 10 kilometres per second for space debris and 20 kilometres per second for meteoroids.
A structure like a solar panel on a satellite can have a small hole punched through it by particles that have a diameter one third of the panel thickness
Here on Earth we talk about dynamic behavoiur of materials when they are exposed to deformations of 8m/s and above.
At and above this threshold we look at the high energy impact absorption capacity and plastic collapse mode of materials.
Typical examples of which are car crush tests to ensure that your new car is not only capable of absorbing energy but doing it in such a way that the car occupants do not experience a high deceleration that is life threatening.
So imagine what happened to the Giotto probe at it passed through the tail of the comet and got close to the comet core.
Thats what makes the filmed images recorded all the more impressive.
Amazing images taken from the Hubble Space telescope of the Comet 73P/Schwassmann-Wachmann 3 breaking up as its eliptical orbit brings it close to a the Sun. Before it swings back out into the universe on its 5.4yr orbit.
Image courtesy esa
Meteoriods are the small particles that are left drifting in orbit around our sun following the breaking up of comets. Most are very small in size no lager than a grain of sand. Some are of sufficient size to survive the entry into our atmosphere. See the film below.
Meteorite filmed entering the Eath's atmosphere over New York(Peekskill) in October 1992.
Reference film source USA educational site
The Huygens/Cassini space mission to Titan, the largest moon of Saturn.
The Huygens module is due to enter the atmosphere of Titan on 14th January 2005.
What will it discover?
An artists impression of the esa Huygens probe approaching the surface of Titan. After a journey that started seven years ago on October 15th 1997.When the Cassini space exploration craft was launched from NASA's Cape Canaveral, Florida. Using a Titan 4B-Centaur launcher.
Cassini Huygens is a joint NASA esa project.
Bigger than Mercury and slightly smaller than Mars, Titan is unique in having a nitrogen-rich atmosphere containing carbon-based compounds that could yield important clues about how Earth came to be habitable. The main problem is the temperature (-180oC) Extremely cold.
Will it discover some form of microbial life
Artists impression of the seperation of the heat shield from the Huygens probe.
surface from 16.2 Kms.
Evidence of river type errosion as it descends towards a coastal interface?
|Titan viewed from 8 kms.|
|Titans surface Success !!|
Or for that matter anywhere else....
'By analysing the interplanetary detritus that has struck the Earth, we can calculate when our planet was born. And life itself? That may have been delivered in kit form by cosmic projectiles',.... says Nigel Henbest
One of the possible origins for life on Earth. Is that life in a simple bacteria or cellular form , could have been transported by metiorites or comets that impacted the surface of our young planet. Transporting both water and a basic form of life.
An analogy to sowing seeds in soil.
Subsequently life flourished on our planet.
In that case it would make us all Aliens!
Every year , 40,000 tonnes of asteroids are ejected from their orbit and fall to Earth as meteorites. More than 70 varieties of amino acids have been found inside meteorites and eight of them are the fundamental constituents of proteins found in living cells.
Channel 4 'The day the Earth was born' Nigel Henbest.
Link to current research into lichen and bacteria being exposed to a harsh space evironment to see if they could survive in space and entry through the earths atmosphere. To prove whether they could be transported by a metiorite.
More recent article Scientists find secret of life..in the stars.
by Science Editor Steve Connor 10 September2004.
A massive impact with a giant asteroid could have kick-started life on Earth more than four billion years ago by providing an ideal environment for incubating the world's first lifeform.
Exoplanet Gliese 581c discovered 24th April 2007
The closest found to date at 20.5 lights years from Earth in the constellation Libra (balance)
Exoplanet similar to Earth discovered 25th January2006
Called OGLE-2005-BLG-390Lb, the
exoplanet is the nearest in size to Earth of the 160 exoplanets so far
discovered by astronomers having a daimeter five times that of the Earth.
However to get there might be a bit of a problem its around 25.000 light
years away from the Earth, close to the centre of our own galaxy the Milky
Way. It has an orbital period of 10 years and is about three times as far
from its parent star as the Earth is from our Sun.
The Independent 20 February 2006
27th Dec 2006 'Corot' esa Cnes mission to explore our universe for exoplanets.
Soyuz Corot launch video
(Click on the title.)
Interesting Independent article written about a recent research project by Richard Gott and Edward Belbruno of Princeton University New Jersey.
2004 The esa SMART lunar probe has an important role in discovering the make up and origins of the rock structures found on the moon. That will help us understand in more detail the character of the Mars sized projectile that collided with the Earth billions of years ago. To formed the Earth as we know it and a belt of aggregate lumps of matter that which had been released by the impact that gradually joined together to form the moon.
|To find out more about our planet Earth. Visit this animated Japanese site. Its worth the time.|
Cutaway of Earths magnetosphere
Giant whirlpools of electrically charged gas , some 40 000 kilometres across, have been identified from data recorded by the esa Cluster formation of four satellites being used to monitor Earth's magnetosphere.
magnetic field generated by the molten iron inside the Earth's core
protects the planet from the electrically charged particles given out by
the Sun. However, it is only a partially effective shield.
Electrically charged gas, known as plasma, can only travel along magnetic field lines within the magnetosphere.
For a particle of plasma to suddenly jump onto a different magnetic field line or change direction there has to be a reconnection event. Where magnetic fields lines spontaneously break and then reconnect with other nearby lines. Redirecting the plasma flow along new routes.
For this to happen, the solar wind plasma must somehow be able to cross the Earth’s magnetic boundary, known as the magnetopause.
This is what is now believed to be happening within the whirlpools of the magnetosphere
This artist’s impression above shows the Earth’s magnetosphere (coloured blue) surrounded by solar wind constantly flowing out of the Sun (coming from the left side of the figure). The white rectangle on the left identifies the area where ESA’s Cluster and China/ESA Double Star’s satellites discovered density holes in March 2005.
The sketch on the top left illustrates these observations: the brown dots representing the solar wind and ions back-streaming against the solar wind flow, along the interplanetary magnetic field lines (shown in black). The elongated ellipses positioned along the magnetic field lines represent a new type of density holes – that are caused by bubbles of superheated gas that are created within the plasma surrounding the Earth that once formed increase in volume before finally collapsing. Within these bubbles the strength of the magnetic field is reduced to almost zero, as illustrated by the thinner black lines within the holes.
|Cluster discovers the detail of Earths 'magnetic null point'.|
On 15 September 2001, the four Cluster spacecraft were passing behind the Earth. They were flying in a tetrahedral formation with separations between the spacecraft of over 1 000 kilometres. As they flew through the Earth’s magnetotail, which stretches out behind the night-time side of our planet, they surrounded one of the suspected null points.
The Cluster group satellites measurements recorded
in 15 September 2001 showed that the null point in the Earth's magnetic
field trailing away from the solar wind ( on the dark side) exists in an
unexpected vortex structure about 500 kilometres across, a characteristic
size never been reported before in observations, theory or simulations.
This sketch shows the spiral structure of the Earth's magnetic field around a so-called 'magnetic null' point, as discovered by ESA's Cluster on 15 September 2001. A magnetic null region is a three dimensional zone where the magnetic fields break and reconnect
Throughout the Universe, magnetic reconnection is thought to be a fundamental process that drives many powerful phenomena, such as the jets of radiation seen escaping from distant black holes, and the powerful solar flares in our own Solar system that can release more energy than a billion atomic bombs.
On a smaller scale, reconnection at the dayside
boundary of the Earth’s magnetic field allows solar gas through,
triggering a specific type of aurora called 'proton aurora'.
Schematic of magnetic field lines recombining to produce a field at 900
finding appear in Nature Physics, in an
article titled "In situ evidence for the structure of the magnetic null in
a 3D reconnection event in the Earth's magnetotail", by C.J. Xiao et al.
(Vol 2, July 2006, pp 478. doi: 10.1038/nphys342).
Latest esa Cluster data reveals magnetic reconnection in outer magnetosheath layer surrrounding the Earth. March2007
Cluster satellites help discover the mechanism that creates the aurora that light up the sky in the polar northern latitudes. Producing the Northern Lights.
Electrons fired into the Earths atmosphere from the sun impact and energise the gas molecules in the high atmosphere (ionosphere) causing them to glow. Certain levels of excitation creating different colours.
Once the gas atoms and molecules have been excited to a higher energy state they will glow. At extremely high energy levels the gas molecules begin to behave as a plasma ( The fourth state of matter).The plasma density will detrmine the nature of the aurora.
A similar mechanism is created when the electron beam, in an old type television set, strikes the phosphore coating at the screen and makes the phosphore glow.
February 10th 2007
Aurora seen over Canada esa
Highly charged streams of electrons that leave the surface of the sun in irregular pulses, created by the nuclear fusion reaction at the centre of the sun ( Changing H > He ). One of the visible effects of the solar stream on Earth is the creation of the aurora.
Solar weather is the study of the changes in the solar wind. Solar flares that are directed towards Earth could seriously damage satellites or reduce there operational life.
|Radio ’screams’ from the Sun, provide early warning
of radiation storms
A CME is a solar slam to our high-tech civilisation. It begins when the Sun launches a thousand million tons of electrically conducting gas (plasma) into space at millions of kilometres per hour.
A CME cloud is laced with magnetic fields and when
directed our way, smashes into Earth's magnetic field. If the magnetic
fields have the correct orientation, they dump energy into Earth's
magnetic field, causing magnetic storms. These storms can cause widespread
blackouts by overloading power line equipment with extra electric current.
Radio loud Coronal mass ejection
Not all CME's are dangerous but those with a precursur radio scream have been identified as events that generate high energy magnetic storms.Some CMEs also bring intense radiation storms that can disable satellites or cause cancer in unprotected astronauts. As the CME blasts through space, it plows into a slower stream of plasma blown constantly from the Sun in all directions, called the solar wind. The CME causes a shock wave in the solar wind. If the shock is strong enough, it accelerates electrically charged particles that make up the solar wind to high speeds, forming the radiation storm.
research, funded by NASA, is presented at the American Astronomical
Society's 210th Meeting during 27-31 May 2007 in Honolulu, Hawaii.
SOHO is a cooperative project between ESA and
NASA, launched in 1995. NASA's Wind spacecraft was launched on 1 November
SOHO is a cooperative project between ESA and
NASA, launched in 1995. NASA's Wind spacecraft was launched on 1 November
|Lightning and Cosmic radiation.
One of the theories for explaining the initiation and branching of lightning discharges . Is that high energy cosmic particles trigger the process as they pass through the electrically charged cloud structure. Creating a route for the discharge to follow.
|Nasa mission to Pluto
Launch 19.01.2006 > Arrival at Pluto 2015.
Initially the Pluto mission probe will travel at a velocity of 16Kms/sec and following a gravitational sling shot when passing close to Jupiter it will increase to 21Km/sec. Satellite mass ms= 478Kgs.The satellite 'New Horizons' controversially uses radioactive plutonium as an energy source and means of generating propulsion. Chosen principly because at the extremity of our Solar system there is insufficient light from the sun to provide enough energy for the spacecraft.
Some of the most important developments in science and physics have originated from our desire to understand how the universe works.
Einsteins theory on relativity was only really accepted after it was confirmed by the observations of light images being bent as they past close to the Sun as had been predicted by Relativity Theory.
It was the English astronomer Arthur S.Eddington who provided the proof during an expedition to Brazil to observe the solar eclipse of 29Mai 1919.To verify if Einsteins hypothesis could be proved.
Note the date1919. Both Einstein and Eddington where pacifists. Eddington had a strong belief in scientists of the world working together to unlock the secrets of nature and the universe no matter what the nationality. Specifically he demonstrated that in ignoring Einsteins theory the world was failing to push at the frontiers of science. Whether the hypothesis was German our for that matter any other nationality; was in fact irrelevant.
Michel Faraday (1791-1867)
Consevation of energy and electromagnetic wave propergation.
James Clerk Maxwell (1831-1879)
|Identified that light was tramsmited as a form of electromagnetic wave. With an unusual property that no matter how fast you travel light will always appears to move away from you at the same speed. 299 792.5 kms/s
Laurent Lavoisier (1791-1799)
Proved the Conservation of mass during any chemical reaction or physical transformation.
During the social turmoil that followed the French Revolution he was guillotined in 1799. Because prevoiusly he had worked for Loius XVI as a tax collector and had run one of the Kings estates.
A shinny new piece of iron wieghs less than when it has corroded and oxidised .
Emilie du Chatalet (1706-1749) 'There is no right time for the truth'
An important female scientist who has been written out of history
An original thinker with a a highly developed understanding of mathematics and science.Her relationship with Voltaire had encouraged the production of several important scientific works
Translated Isaac Newtons 'Principa Mathematica' into French completeing the work just before she died giving birth to her third child. She took the side of Leibnitz in supporting the view that energy was proportional to the sqaure on the velocity v2.
(d/dv) mv = 1 mv2
Energy E a v2
That is Energy is proportional to the velocity squared.
This was later to be adopted by Einstein in his energy equation. E = mc2
Leibnitz had died in 1716 shortly after a dispute with Newton had left him excluded from the scientific community and left destitute by his German patron. who had moved to England to become George 1.
Newtons desputes with Leibnitz ressembled that he had with Robert Hooke. Both became victims of the power of Isaac Newton to protect the originality for his theories.
As this article shows this is rarely the work of one person alone. Newton and Einstein achievements relied on the achievments of scientists both before and after.
Female Austrian scientist who was forced to leave her research post in March 1938 after Hitlers rise to power put pressure on all Jewish researchers to leave Germany. Leaving behind all her possesions she fled to Sweden.
She should have been given the 1945 Noble prize for chemistry that had been mistakenly given to Otto Hahn. This was eventually rectified in 1966.
Working after Einstein proposed his famous equation, she was the first to show that a uranium atom can be split, converting a tiny amount of mass into a prodigious amount of energy, according to the formula E = mc2. This discovery eventually led to the development of the atomic bomb.
|Einstiens famous formula
Has a less well known derivative
Where p is momentum. Which has been used to justify the existance of very high energy particles with negligible mass. Like neutrinos that after travelling through space pass straight through planet Earth. However they should be detectable from the bluelight they emit as they loose momentum.
Time > Clocks Cold play
General Relativity survives gruelling pulsar test.
Jodrell Bank Observatory Radio telescope
Einstein's theory of General Relativity is proved to be 99.95% right by Jodrell pulsar research findings. September 2006
Jodrell Bank Observatory also celebrates the 50th anniversary of the launch of 'Sputnik' by Korolev's soviet team of engineers.
'Sputnik' the first man made satellite placed in orbit around Earth by R7 Semiorka on 4th October 1957.
It was Jodrell Bank - the only man-made object capable of tracking Sputnik - which confirmed to the world that the space age had begun.
Jodrell Bank was the only radio telescope capable of tracking Sputnik. That was used to officially confirm the launch of 'Sputnik' by the Russians; and signal the dawn of a new space age.
It was a rather unique experience as Bernard Lovell, now aged 90 recalls . “Both the Soviets and Americans had the ability to launch payloads into space, but no means of tracking them!”
After the tracking of Sputnik, Jodrell Bank and Bernard Lovell became world famous and subsequently were used to independently confirm all of the Soviet missions,
BBC Radio4 ' Dish of the day' Programme about Jodrell Bank.
http://www.bbc.co.uk/radio4/science/rams/dishoftheday.ram <Click and listen
Yes we know it all. Well not quit!
|Composition of the Universe
Visible matter and matter that is made up from atoms and molecules only accounts for some 5% of the Universe.
We are still trying to fathom out what the remaining 95% is used for!
This should begin to explain why we need to explore and discover how our universe works.
Results from the WMAP satellite published in March 2006 indicated that in addition to dark matter more than 75% of the universe contained a mysterious antigravity force which astrophysists named 'dark energy'
The Independent 6.02.2006
By Oliver Duff
15th May 2007 Dark matter ring discovered in the galaxy cluster C10024+1652 by Hubble space telescope. Using gravity lensing method.
A blue coloured halo indicates the presence of dark matter
The ring-like structure is evident in the blue map of the cluster's dark matter distribution. The map is superimposed on a Hubble image of the cluster. The ring is one of the strongest pieces of evidence to date for the existence of dark matter, an unknown substance that pervades the universe.
Astronomers suggest that the dark-matter ring was produced from a collision between two gigantic clusters.
Dark matter makes up the bulk of the universe's material and is believed to make up the underlying structure of the cosmos
XMM-Newton Satellite scores 1000 top-class science
Beyond the visible. X Ray imaging used to unlock the secrets of the universe.
Scientific American 2006
Collision of two galaxies provides first proof of the existance of dark matter.
3D Map of Dark Matter January 7th 2007
This three-dimensional map, obtained thanks to HST ( Hubble Space Telescope) and esa Xray XMM-Newton data, offers a first look at the web-like large-scale distribution of dark matter, an invisible form of matter that accounts for the majority of the mass in the universe.
A good analogy is that it's like trying to draw a map of a major city when its night and there's no street lighting.
In the above image the length of the box represents time and distance from Earth Starting from the left and reaching further into he universe as you go to the right.
Whilst the lefthand square window represents a sky window area of space equivalent to a 1.6 0 square carot or 9* the size of a full moon
Using a phenomenon known as gravitational lensing, to investigate an area of the sky.
Gravitational lensing , first predicted by Albert Einstein, occurs when light from distant galaxies is bent by the gravitational influence of any matter that it passes on its journey through space.
"We have, for the first time, mapped the large-scale distribution of dark matter in the universe," said Richard Massey of the (Caltech) California Institute of Technology in Pasadena, one of the lead scientists in the team. "Dark matter is a mysterious and invisible form of matter, about which we know very little, yet it dominates the mass of the universe."
One of the most important discoveries to emerge from the study is that dark matter appears to form an invisible scaffold or skeleton around which the visible universe has formed.
Nature article January 2007 Announcing three dimensional model of dark matter distribution in the universe
The XMM Newton X Ray satellite discovers a mega ball of gas and flame measuring 3*106 light years across at the center of a galaxy cluster called Abell 3266. Having a mass 1*109 that of our own sun moving at an incredible 730 Kms/s.
Here the orange shape defines the gas ball at the center of Abell3266.which is 5*109 times the size of our galaxy.
The maximum velocity currently known is the reference velocity of light in a vacuum of 300000 Km/sec
Even so 730 Km/sec is 100 times the escape velocity from Earth that is also known as the First Cosmic velocity.of 7.2Km/s.
or 0.0025e where e is the speed of light.
cluster 3266 is part of the Horologium-Reticulum super-cluster and is one
of the most massive galaxy clusters in the southern sky. It is still
actively growing in size, as indicated by the gas ball, and will become
one of the largest concentrations of mass in the nearby universe.
September2006 The esa XMM Newton XRay satellite and the US MOST telescope have been working together to date the remains of a supernova RCW 86. By quantifying the temperatue and the velocity of the expanding material. They have been able to approximate the date at which the supernova occurred to some 2000years ago.
This means that RCW86 could be the remains of the supernova recorded by Chinese astronomers in 185 AD. One of the earliest known Supernova recorde by man.
Credits: ESA/XMM, NASA/CXC, University of Utrecht (J. Vink)
Colour coded image: Red low energy
Green average energy
Blue high energy Xrays.
|When a massive star runs out of fuel, it collapses on itself, creating a supernova that can outshine an entire galaxy. The intense explosion hurls the outer layers of the star into space and produces powerful shock waves. The remains of the star and the material it encounters are heated to millions of degrees and can emit intense X-ray radiation for thousands of years.|
|After the initial explosion the bright light generated by the supernova within our own galaxy would have been visible for about 8 months,|
esa Integral satellite discovers a new classification of Supergiant 'X ray' binary star.
16 November 2005
The new class of double star systems is characterised by a very compact object that produces highly energetic, recurrent and fast-growing X-ray outbursts, and a very luminous ‘supergiant’ companion.
The image above recording an interaction between some small very dense stellar object that can be seen in the wake of the solar wind created by the supergiant
|What is the size of our universe?
Our current estimation is based on the time it is possible for light to travel since the creation of the universe.
It would be impossible to see further. As it would not have existed.
So assumning the universe is 14 *1012 years old.
Then the distance it is possible for light to travel in a vacuum during that period.
One light year is equivalent to 9500*1012 Kilometers or 9.5* 1015 meters.
So 14(9.5) .1012.1015 = 1.416 * 1019
So an approximation based on the above assumptions give a Universe with radius of
1.416 * 1019 meters
and a diameter of 2.8*1019 meters.
But this assumes that the universe is static, does not expand and that time itself is not deformed.
Another major assumption is that the universe is not itself moving relative to some other bigger universe.
BBC World Series Dont miss the bbc world series 'Space and Time'
broadcast during May 2005.
Could the extra dimensions of time allow a parallel universe to exist?
What if a collison between time zones could be responsible for creating the original Big Bang .
bbc Horizon Is there a parallel universe
Having been given a bad press by the scientific community due to there intense density creating a gravity that gives them the ability to absorb everything that comes close to them including light. Black holes have recently been discovered at the center of most galaxies. Including Andromeada and our own Milky Way. The hypothesis is that they can exist in several states.
One where they pull in the swirling gas clouds towards the black hole at there center generating tremendous heat and energy Which cause the 'active galaxies' to appear to glow white hot at its center.
These black holes feed on the matter surrounding them with the extremely high/intense temperatures and pressures encouraging the matter to condense into stars. Effectively encouraging the formation of immense clouds of young stars. Which will make up a new galaxy.
And a second equilibrium phase occurs where the black hole stops feeding on material and settle down to achieve a form of energy balance between the gravity of the 'black hole' at its center and that of the combined rotational energy of the millions of stars that turn about its axis.
The effective mass of the black holes found at the center of a galaxy account for 0.5% of the total mass of the galaxy.
Could the first phase be capable of explaining how galaxies are formed?
Two independent researchers Prof Laura Ferrerese and Prof Karl Gebhardt using the largest Earth based telescopes available and images from the hubble space telescope. Have identified that a linear relationship exists between the size of the black hole found at the center of each galaxy and the rotational velocity ( s sigma ) of the outermost stars at the perimeter of the galaxy .
Confirming an earlier hypothesis of the Oxford University Astrophysics team lead by Professor Joseph Silk and Martin Reece.
Nova programe on black holes
Massive Black Holes
Independent article Solved: the mysteries of the black hole
Stephen Hawkins An explaination of how 'Black Holes' and the concentrated point at there center called 'the singularity' function.
How to calculate the mass of a black hole
XMM-Newton X Ray telescope has helped find evidence for the
existence of controversial Intermediate Mass Black Holes.
The first, “Quasi-Periodic Variability in NGC 5408 X-1” , is by T.Strohmayer, R.Mushotzky, L. Winter, R. Soria, P. Uttley, M. Cropper.
The second paper, “Determination of Black Hole Mass in Cyg X-1 by
Scaling of Spectral Index-QPO Frequency Correlation”, is by N.
Shaposhnikov and L.Titarchuk.
France Culture Continent Science Micro trou noir September 2007
French Radio programme discussing the theory of relativity and the existance of black holes of univeral and micro scale.
Currently a total of 1018black holes are thought to exist in our universe.
Micro black holes are thought have just three main parameters:
Entropy> They have a very high level of entropy for there size.
Temperature> Unlike normal objects when they radiate heat energy they warm up instead of cooling down
Tracability > When they transform energy they retain no trace of the material from which it came from.
|Time and the universe.
|Understanding the gravitational attraction force
between two masses.
Do we know what creates the weak gravitational force used by Newton in his gravitational mechanics formula and accepted up to present.? In short. No we don't.
Houston. We have a problem!
F = G m. m'/ r2
Universal gravitational constant G = 6.67259. 10-11 Nm2/Kg2
F = G
F = M. A
A = G
G = =
For there to be a change in the universal graviatational constant G. There would need to be a change in either time, mass or density
Using Newton's definition of gravity we cannot explain why the stars rotate around a spiral galaxy hub at a far greater velocity than would be thought either possible or stable. Without the stars being flung off into outer space. To compensate for this we make up an imaginary mass and energy (Dark matter and dark energy) within the structure of the spiral galaxy to allow the stars to stay in a stable fomation as they rotatate about the galaxy's center.
The problem is we still have not been able to identify the existance of either dark matter or dark energy. Even though it has to account for 95% of the universe! For our current understanding of gravity to be an acceptable explaination.
Just maybe we do not really understand what gravity really means.
If there was a school report this would be equivalent to 1/20. With the comment 'Consderable work needed'
Panoramic view of the Milky Way viewed from Earth
Mach's concern about our relative velocity in the universe:
Our galaxtic year is estimated at 250*106yrs
This is the time it takes our solar system to rotate around our galaxy
Our position within our galaxy is 25.897*103 light years from the center or hub
Gravitational constant G = 6.67.10-11 Nm2/Kg2
Does gravity exist in wave form and travel at the speed of light ?
Gravity The weak force that glues the universe together.
Understanding the weak gravitational force between two masses 1N = 105 dynes (cm/s2)
Experiment to illustrate the weak attractive force between masses
|LISA An esa satellite group that will be launched in
2015 in search of gravitational waves.
Three identical satellites will be flown in formation in an orbit around our sun. Looking for proof of the fourth weak force gravity being transfered throughout space by gravitational waves travelling at the speed of light.
|Gravtational field effect generated by moving
Gravitomagnetic field created when a superconducting mass is accelerated.
"This experiment is the gravitational analogue of Faraday's electromagnetic induction experiment in 1831."
A 'Gravitational field effect' of a rotational mass has been discovered ,by researchers financed by the esa, and could help explain the difference with that predicted by quatum physics.
Although only 1*10-8 times the value of g (9.81m/s2) this makes it 1*1024 larger than the value predicted by quatum theory.
Video of interview with Dr Martin Tajmar STAIF 2006
Dr. Martin Tajmar is a research scientist and project manager in the Space Propulsion group at ARC Seibersdorf research, Austria's largest research institution, STAIF 2006 interview to discuss a variety of topics, including gravito-magnetic fields in superconductors & applications for advanced propulsion...
|The Pioneer Satellite Anomaly
The NASA exploration satellites Pioneer 10 and 11 have been identified to have experienced an unexpected acceleration towards the sun of 8.74+ 1.33, 10-10 m/s2.
Approximately somewhere in the range 7.4 > 10.10-10 m/s2.
Or alterantively as a relative acceleration in time of at = 2.92 + 0.44.10-18s/s2
Possible Error in the value of the Gravitational constant G = 6.67.10-11 Nm2/Kg2?
Both satellites appeared to slow down more than was expected as they headed towards the extremities of our galaxy.
On 13th June 1983 Pioneer 10 passed the last known planet of our solar system and headed into inter stellar space
The acceleration anomaly with Pioneer 11 seems to have coincide with its fly-by of Saturn in September 1979.
Normally once a satellite has been given a Dv then it will continue with this velocty in what is refered to as a true Galleen movement. Because in the vacuum of space and the absence of any gravitational effect ,due to the proximty of planets from our solar system, there should be minimal frictional loss to impede its progress through spce. Well that's the theory
Pioneer 10.has slowed down and is now 400 000Kms behind the position extpected by the original NASA flight plan.
Distance currently from the Sun 14.109 Kms
Velocity relative to Sun 12.07km/s
Retard 400 000Kms.
Distance from the Sun 10.8 .109Km
Velocity relative to the Sun 11.36Km/s
2006 Is the physics within the solar system really understood?
The list of possible origins for the Pioneer Anomaly can be split into two generic groups:
Possible External Causes:
1.Aerial Reciever. Earth based recieving station error due to faults in calculating either there accurate postion due to plate tetonics continental drift and the accurate speed of rotation of the Earth.
2.Solar Wind. This could have delayed or interfered with the radio signals being sent back to Earth.
3.Inter planetary dust. A higher density of interplanetary dust could have created a higher than expected space drag.
4.Kuiper belt . Having a higher density than expected.
5.The gravitational influence from other stars in our galaxy. Galaxtic Force
6. Dark Matter Affect on the space exploration probe of some unknown dark matter halo.
7.Expansion of the universe. Altering the relative position of the Pioneer probe and Earth.
Possible Local or Internal Causes
1. Hydrazine Leak A leak of fuel used for the positioning/ attitude thrusters.
2.Helium leak. The three mini reacters(RTG) producing helium that then escapes in a direction that slows the space probe.
3.Infared emissions from the reactors. Heat radiation from the two mini nuclear reactors reflecting onto the rear of the radio communication dish. Creating a braking force on the probe.
Indications as to the origin of the retardation force could be indicated by knowledge of its vector direction.
1.If it is oriented towards the Sun> Then this would indicate that there is an error in the gravitational theory of General relativity.
2.If orientated towards the Earth> Then this would indicate that there was a radio communication/Earth reciever based error.
3.Orientated along the trajectory of the probe> This would indicate a retardation force due to the quality of space through which the probe was flying or to causes within the probe.
4.Pointing along the axis of rotation> Would indicate an internal probe based leak or local emmission wave.
And the winner is?
esa is talking about the possibility of launching a space exploration probe just to track down the Pioneer satellite and record its axes of retardation.
This error is not unique. So the esa has decided to closely monitor the flight trajectories of all its satellietes and space probes. To be able to explain any abnormal accelerations or deviations from the original flight plan.
Our Galaxy the Milky Way
In search of particles.
So how big are they?
Benjamin Franklin ( 1706 -1790)
'Pouring oil on troubled waters'
Whilst in England representing the interests of the US Franklin carried out the following observation.
The surface ripples on a small lake where calmed when a teaspoon 5mls of oil was poured onto the surface of the water.
From the area of the lake surface 4047m2 (1 acre) and the volume of oil 5cm3
Franklin was able to calculate the thickness off the oil film produced that would cover the lake.
V= 5cm3 =5* 10 -6
Volume V = A*t
t = V/A = 4047 / 5* 10 -6
t = 0.8 * 10 -9m
Such a thin layer of molecules can completely change the properties of the liquid surface.
What we now refer to as a nanofilm of molecules can change the surface tension properties of water .
Another example of this is the oily wash that trails behind a whale also calms the surface of the seain its wake.
|Understanding the gravitational attraction force between two masses.|
The study of Brownien movement was the precurser of relativity and is the analysis of how particles are displaced within a fluid
Note:Browmien movement is the random movement of fine particles of pollen or mineral powder within a fluid first obsevered by Robert Brown in 1827.
Video showing Brownian movement of fat droplets in milk varying in size from 0.5- 3mm
Copyright Dave Walker
Java model showing gas molecules bouncing
off and interact with oneanother. note how the reference red
molecule is displaced;
In 1905 Einstien became interested in Brownien movement as it could be used to confirm the existance of atoms and molecules held in suspension within a liquid. As they impacted the particles in suspension causing there erratic motion.
dx2 = 2Dt
D is the coefficient of diffusion D = RT / Nf
Where R is the Gas constant.
T the temperature of the liquid.
f is the drag coefficient and N the Avagadro number > 6*1023
Langevin used the following to define the same movement.
m dv/dt = Fdrag + F stochastic.
Fstochastic being the probability of a force
acting in a random direction with time.
|Does water have a memory for remembering its former
A controversial idea that water when in solution with other substances can retain a memory of this original structure even after it has been heavily diluted. Is stimulating debate as to whether this is possible.
Most scientists seem to be very sceptical. The French scientist Jacques Beneviste responsible for these claims was removed from his post at the ISERM and awarded not one but two Ig Nobel prizes that are equivalent to the best scientific joke of the year award.
|Every material can be broken
down into its basic elements that now are thought to be characterised by
the energy levels and the resonanant condition of strings from which they
So for example the string type that determines the character of an electron is different from that that charaterises a quark and will vibrate in a different way.
Similaraly the forces that bind an atom together are also determined by the energy level of the strings found within the constituant parts.
So thats where gravity comes from. A series of wriggling strings that make up gravitrons. When they resonate together or in phase they produce a force.
|Resonance in Strings.|
|Key Dates in the development of the string
1968 Gabriele Veneziano (Cern) Identifies an equation based on the hypothesis of vibrating cordes or strings. To explain the existance of the 'strong' force that bind neutrons and protons together in the nucleus of an atom.
1984 A modified version of the string equation develops the string hypothesis into a more general theory.
Model identifies the existance of the photon and graviton. Offering a possible explaination of how energy can be retained by a particle like the graviton with negligible mass but high energy spin.
1995 Edward Witten Princeton University USA Identifies that eleven and not twenty six dimensions are required to define strings mathematically.
|So what's a neutrino.
The ghost particles that change vibrational mode as they pass through the Earth.
|BBC radio 4 programme on graviton research 2005|
|How small is is as small as you can measure
25.04.2007 MIT manage to weigh a single biological cell of 1 zeptogram 10-21grams
You want a map of the sky and space; to find out where the planets are located.
A good place to start is 'SkyMap Pro 7'
Certainly one of the best sites to discover astronomy is that of the bbc.
The esa integral satellite has helped to discover a pulsar star combinanation.
Pulsars are rapidly rotating neutron stars whose speed of rotation can be related to the feeding of the pulsar by gas ripped off from the surface of a companion star. The ionised particles of material taken from the star are pulled into the magnetic field of the pulsar and impact its surface emitting jets of 'X' rays and gamma radiation. Pulsars are dense having approximately the same mass as our sun but measuring only 20 kms in diameter.
Animation of pulsar devouring material from its companion star. The strong magnetic pull of the pulsar rips off the material from its companion star. Increasing the energy of the pulsar which begins to spin faster.
If the rotating pulsar fails to feed of neighbouring stars it would eventually slow down. Imagine a type of giant gyroscope that spins for two hundred thousand years
Integral discovers cannibal stars deavouring gas streams
Hubble image of the Crab nebula.
Looks like some ones just plonged into the swimming pool
If we used the level of gamma radiation emitted by an object instead of the visible light emitted . Then the Crab nebula would appear as the brightest point in our universe. The gamma energy emitted is 1012 times more energetic than light.
To find the Crab nebula in the night sky follow the link
Then type Crab nebula in the search window.
|Integral satellite identifies
supernova rate for Milky Way
Spiral galaxies like our own Milky Way are made up from millions of stars. At the center the stars are grouped together rotating at a higher velocity than the stars at the exterior.This group of stars at the hub form an elongated elliptical or bar form. Each star beyond this hub of stars describes an elliptical orbit about this centre mass of stars never returning to the original starting point. This elliptical displacement of the stars orbit will ultimately become attracted by the gravitational forces of neighbouring stars which once aligned have an increased gravitaional influence on that area of the gallaxy. A form of gravitational wave aligns the major axes of the elliptical orbits. The Spiral arms of the galaxy are then formed where these slowly rotating ellipses touch. Creating a higher density of stars. Subsequently the curved arm of the spiral is caused by processional velocity of the stars as it reduces the further they are from the center.
The angular velocity of the star density wave which is created within the galaxy is of a constant value from its center to the outer perimeter. Whilst the value of angular velocity for individual stars reduces as the distance from the center increases.
The Center of corotation is where the angular velocity of the stars is the same value as that of the density wave.
The inner and outer radius limits of the spiral arms are defined by the Lindblad resonance values for the star clusters. These occurr where the precession velocity of the orbits is a mulitple of the star wave density. So creating a resonant condition.
Our own sun takes aproximately 250 million years to rotate around our Milky Way galaxy.
|esa SOHO satellite keeps an observing eye on the
Sun images recorded by the satellite can be foiund on the link below.
|‘Comet Galaxy’ being ripped
apart by tidal pressure of a galaxy cluster.
2 March 2007
The NASA/esa Hubble Space Telescope, in collaboration with several other ground- and space-based telescopes, has captured a galaxy Abell 2667 being ripped apart by a galaxy cluster's gravitational field and harsh environment.
The finding sheds light on the mysterious process by which gas-rich spiral-shaped galaxies might evolve into gas-poor irregular- or elliptical-shaped galaxies over thousand millions of years. The new observations also show one mechanism to form the millions of 'homeless' stars seen scattered throughout galaxy clusters.
22nd May 2006
'Akari' the recently launched Japanese satellite with infrared Far (FIS) and Near(IRC) telescopes. Sends some of its first images that capture the birth of young stars in the nebula IC4954. Some 6000 light years away.
In these first infrared images of this area it is
possible to see individual stars that have recently been born. They are
embedded in gas and dust that would not have been visible using
traditional telescope analysis of the visual part of the spectrum.. But
with the aid of infrared imagery it is possible to see them and the
gas clouds from which stars are made.
Multiple images of the M81 spiral galaxy 12 million light years away, taken at different infrared wavelengths.
These infrared images of the galaxy M81 were taken by the near- and mid-Infrared Camera (IRC) on board Akari. The observed wavelengths are 3, 4, 7, 11, 15, and 24 microns, respectively. M81 is a spiral galaxy located at a distance of about 12 million light years from us.
The images at 3 and 4 microns show the
distribution of stars in the inner part of the galaxy without any
obscuration from intervening dust clouds. At 7 and 11 microns it is
possible to see the radiation from organic materials in the interstellar
gas of the galaxy. The distribution of the dust heated by young hot stars
is exhibited in the images at 15 and 24 micron, showing that the star
forming regions sit along the spiral arms of the galaxy.
Satellite measurement of the hole in the ozone layer at the South Pole.
Global observation by satellite. Monitoring climate and weather patterns to predict potential disasters. A very comprehensive site that can stimulate an understanding of our world viewed from space.
European satellite observation images of Earth climate changes.
Available for teachers in five languages: German, English, Spanish, French and Italian.
So how big is the hole in the ozone layer?
Why is this important?
What are we doing about the cause?
October 2006 Record hole in the Antartic ozone layer
In the !970's the British Antartic Survey research scientists reported the reduction in the ozone level in the lower stratosphere above Antartica.
In 1974 DrMario Molina MIT in an article for 'Nature' predicted upper atmosphere ozone layer depletion. Due to the waste chlorofluorocarbon (CFC) gases created by aerosols, refrigeration and air conditioning fluids and styroform.
But in fact under estimated the actual size of the problem.
CFC's would be transported up to the outer ozone layer. Where exposure to intense ultra violet light would decompose the CFC's into there reactive elements. The chlorine atoms liberated would then reduce the ozone layer in the upper atmosphere. Exposing all living organisms on Earth to harmful radiation.
1985 Saw the confirmation of a 50% depletion of the ozone layer above the South pole by UK Antartic researchers.
Highlighting an error in data interpretation taken from an USA ozone monitoring satellite.
Satellite data analysis had under estimated the ozone depletion by a factor of 10.
In 1987 the United Nations 'Montreal Protocol,' banned the most dangerous CFCs. This came into effect in 1996.
Then in 1995 Crutzen , Molina and Rowland shared the Nobel prize. Crutzen had shown that nitrogen oxides actually accelerated the rate of ozone reduction
2004 We are still allowing third world economies to produce CFC's gases until 2040.
Not all signatory countries are conforming to the reduction of CFC's.
The latest predictions are that the depletion of the ozone could be recovered by 2070.
Providing we do not invent other new ozone destroying chemicals/processes.
Response time 100yrs.
For more detailed information.One of the best sites is that of the
University of Cambridge, Center for Atmospheric Science.
esa October 2006 The largest ozone loss on record is recorded at South Pole.
Dobson units are used to measure the thickness of the ozone layer in the atmosphere.
This is the thickness of the ozone found in a column of atmosphere of unit area 100*50 once it has been normalised to a temperature of 1oC and pressure of 1bar. At thickness of 3mm is equivalent to 300 Dobson Units (DU)
Ozone (O3) is an allotrope of oxygen. It is formed from electrical discharges or ultraviolet light acting on O2. It is an important component of the atmosphere (in total amounting to the equivalent of a layer about 3 mm thick at ordinary pressures and temperatures) which is vital in preventing harmful ultraviolet rays of the sun from reaching the earth's surface. Aerosols in the atmosphere have a detrimental effect on the ozone layer. Large holes in the ozone layer are forming over the polar regions and these are increasing in size annually. Paradoxically, ozone is toxic! Undiluted ozone is bluish in colour. Liquid ozone is bluish-black, and solid ozone is violet-black.
Polar stratospheric cloud PSC
These pretty 'mother of pearl ' type clouds are being analysed using a satellite based Michelson Interferometer for Passive Atmospheric Sounding or MIPAS for short. To identfy the chemical compostion of clouds in the polar regions which degrade the level of ozone in the high atmosphere.
Some PSC's contain fine ice crystals whilst others contain a nitric acid based compound konwn as NAD .nitric acid trihydrate.
Satellite channel BBC World 'Earth Report' Documentry Sky Pirates
Environmentalist are concerned over the sudden increase in CO2 in the atmosphere
Satellite surveys of Earths atmosphere are trying to understand the short and long term effect of increases in 'green house' gases.
|esa Soil Moisture and Ocean Salinity SMOS
SMOS satellite animation. Monitoring Earths water resources.
|Global methane and carbon dioxide
Envisat satellite SCIAMACHY data reveals global methane and carbon dioxide distribution that contribute to global warming.
Global CO2 distribution
Global methane distribution
First world maps of methane and carbondioxide distribution. These are the principle gases responsible for climatic warming due to the 'green house' affect Envisat data
IPCC World Environment Report 2007 4th Assessment Report
Al Gore and the IPCC team won the 2007 Nobel Peace prize for there work on the effect of world pollution on our environment
World land temperature increases, rising sea levels and an increasing acidity of our oceans are the direct result of the hydrocaben energy economy on which our society currently depends.
The increasing acidity of the upper layer of the oceans will reduce the plankton population.
One of the ommissions in the report is the effect of global warming on the release of methane from the
large reserves of Methane hydride trapped under the continental plates and the perma frost regions.
IPCC draft report [9.3MB]
Glossary and explainations of terms used in the report
World climate in crisis Film 'An inconvenient truth'
esa joins UN in climate control talks in Kenya. esa proposes monitoring the earth's carbon dioxide storing forest.
By Steve Connor, Science Editor
By Steve Connor, Science Editor 29th January 2007
A draft copy of the fourth report of the Intergovernmental Panel on Climate Change (IPCC) says that global temperature rises this century of between 2C and 4.5C are almost inevitable. Ominously, however, it also says that much higher increases of 6C "or more" cannot be ruled out.
By Michael McCarthy, Environment Editor 24.1.2005
The global warming danger threshold for the world is clearly marked for the first time in an international report to be published tomorrow - and the bad news is, the world has nearly reached it already.
|Climate change and Global disaster monitoring|
|BBC World Earth Report|
Mondays @ 21.30 GMT
Repeated on Tuesdays @ 02.30, 09.30 & 1730 GMT; Saturdays @ 16.30 & 1930 GMT and Sundays @ 07.30 GMT
Independent article 19 February 2005
By Steve Connor, Science Editor in Washington.
Two mathematical models developed seperately in the US and in the UK based on millions of temperature readings taken from all of the worlds oceans have shown how the worlds ocean temperature has acted as the heat sink to global warming of the atmosphere.
There is now a global threat which requires all governments to sign up to the Koyoto agreement and act to reverse the pollution of our atmosphere.
Fish numbers plummet in warming Pacific
Disappearance of plankton causes unprecedented collapse in sea and bird life off western US coast
By Geoffrey Lean in San Francisco
Published: 13 November 2005
The Independent Newspaper
World Environmental Treaty to reduce atmospheric
President of the British Royal Society of Science accuses President Bush of deliberately avoiding all the scientific evidence that links environmental pollution with 'Global Warming'.
Conformity with Kyoto treaty reduction in 'Greenhouse gas' emmissions confirmed by satellite.
A reduction of 5% is required to conform with the Kyoto agreement
By the end of the century half of all species will be extinct. Does that matter?
By Julia Whitty
Published: 30 April 2007
Environment Section of the Independent
The Independent brings the environmental issues from the fringe to the front page
Pioneering the importance of environmental issues as the Indepnedent promotes the issue to the Front Page.
|One famous environmental quotation from Albert
“If the bee disappeared off the surface of the globe then man would only have four years of life left. No more bees, no more pollination, no more plants, no more animals, no more man.”
Who will look after his future?
Photograph by John Gwynn
|Click for larger esa image|
Earths atmosphere is in fact a very thin, fragile layer.
If we assume that the effective outer limit of our planet is somewhere within the stratosphere at 40Kms above the surface. Where our atmosphere's density and pressure has reduced to a very low level.
Then taking the average radius of the Earth to be 6375Kms.This would make the atmosphere to be just 0.63% of the radius of the Earth. Thats less than 1% of the radius of our planet. Very thin and fragile.
The mixture of different molecules of gas that make up the atmosphere above our planet is in fact held there by the gravitational attraction pulling each molecule towards the center of the Earth.
This force balances the outward centrifugal force, created by the spinning Earth, trying to launch them into space.
This makes Earth almost unique in that its size and gravitational force enable it to maintain an atmosphere. Without it disappearing into space.
The fact is. We are very lucky to have an atmosphere that is capable of supporting life.
Yet we seem determined to destroy this precious gift.
|Why is the sky blue on Earth during the day and not
black like the moons?
Because the Earth has an atmosphere made up from a particular mixture of different gas molecules. water and dust particles. It diffusses sunlight arriving from sun in a specific way.
If we assume that the Earths atmosphere is made up from 78% NO2 (Nitrogen Dioxide), 21% O2 qxygen,. carbon dioxide and water. The structure of the molecules that make up our atmosphere vibrate in a certain way when excited by the light arriving from the sun and have a predispostion to diffuse the shorter wavelengths within the visible electromagnetic spectrum that range from 400um (violet) to700um (red). Due to a law of physics identified by Robert John Rayleigh our atmosphere diffuses sixteen times more violet/blue light than it does red.
Using the same law the sky on Mars is orange / pink because the principle constituent of the atmosphere on Mars is carbon dioxide which has a preference in helping to diffuse the longer wavelengths of the electromagnetic spectrum that tend towards the red.
Our sun appears slightly yellow because a large part of the shorter blue light wavelengths have been absorbed as the sun rays pass through the atmosphere. As the sun approaches the horizon the thickness of the atmosphere through which the light arriving from the sun has to pass increases. Progessively more of the shorter wavelengths are absorbed as the colour of the light reaching our retina passes through a transition from yellow to orange and red as finally only the longer wavelengths are left.
So one of the simple ways of trying to identify whether another planet will support life similar to that on Earth is to look for the one with a similar size supporting a blue coloured atmosphere.
esa Earth satellite images
Fantastic new esa site to access satellite images in near real time
Earth Observation Satellites
esa Earth health check up
La Nina the cold sister of El Nino is observed by Envisat
Ten year global vegetation survey
esa Global carbon project using satellite monitoring of world vegetation distribution over a 10 year period
Global sea height measured using different satellites
'Envisat' measurement of sea wave height corrected.
Different colours indicate different wave heights.
Voilet/purple is calm.
Red indicates a rough sea with high wave height.
The esa Envisat satellite has a 800km scanning polar orbit. With a mission to survey changes at the surface and in the Earths atmosphere.
Envisat weighs 8000kgs, 10m long and 25m wide ( with the solar panels deployed ) and has been in orbit since March 2002.
To follow the state of the planet through the eyes of Envisat:
In English for the latest world ozone status.
Independent article on the historical rate of change in the world sea level .25Nov 2005
Multi-language site by esa to access satellite images for educational purposes German, English, French, Spanish and Italian.
Images of Mars, Saturn, Titan and the Huygen/Cassini space mission courtesy esa
Is there life somewhere else in the universe?