- The European Space Agency has released the early results
from its Mars Express probe now orbiting the Red Planet.
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- The data include a batch of remarkable pictures taken
at very high resolution.
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- The images show what appear to be sediments left in the
bottoms of river-cut valleys, and details as fine as dust blowing over
the rims of craters.
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- "This is no ordinary spacecraft," said David
Southwood, Esa's head of science. "This is only the beginning. There
is more to come in the next two years."
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- The science results were released at a news conference
at Esa's Space Operations Centre in Darmstadt, Germany.
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- The event took place as the US space agency attempted
to make full contact with its Spirit Mars rover, which has inexplicably
stopped sending data back to Earth.
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- Amazing sights
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- The European orbiter's instruments have also revealed
new information about the stores of water-ice at the planet's south pole
and the way it is mixed in with frozen carbon dioxide (CO2).
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- In addition, Esa scientists say they can see, for the
very first time, water being lost from Mars' atmosphere.
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- But it is the images taken with the probe's High Resolution
Stereo Camera that have generated the greatest excitement.
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- The camera can see details down to two metres and German
researchers working on the mission have even constructed computer-generated
movies from the pictures to show what it would be like to fly over the
Red Planet in an aircraft.
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- The camera's lead scientist, Gerhard Neukum, from the
Free University in Berlin, said Mars Express had already imaged nearly
two million square kilometres of the Martian surface.
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- The area, covered at a resolution of 10 to 15 metres
per pixel, was equivalent to the land coverage of France, Germany, Italy,
Spain, Portugal and Austria combined, he said.
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- His team has already received more than 100 gigabytes
of processed data - most of which has not even been looked at yet.
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- "We have done some instant science and I think we
can firmly say 'yes, there was water acting on the surface of Mars',"
Professor Neukum said.
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- His pictures show what appear to be sediments left in
water-cut valleys and at the bottoms of craters which other instruments
on the probe will now try to identify. There were also features that had
been pictured that appeared to be evidence of glaciation, he added.
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- Sun erosion
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- It is still very early in the two-year mission of Mars
Express, but project scientists say they are thrilled with the initial
returns of data they are getting from the spacecraft.
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- "We have already identified water vapour in the
atmosphere and water-ice in the soil on the southern polar cap," said
Vittorio Formisano, who looks after the probe's Planetary Fourier Spectrometer.
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- "We can identify water directly on the planet,"
added Jean-Pierre Bibring, from the Institute of Space Astrophysics, Orsay,
France.
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- "It's mixed with CO2 essentially but if we go to
areas which are a little warmer where there is no CO2, we have remaining
water there."
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- At the end of the mission, he said, scientists should
know the precise volume of water-ice still remaining on the planet's surface.
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- The US space agency's Mars Odyssey orbiter has already
given a strong indication that there is water-ice on the southern pole.
Its assessment comes from the use of a gamma ray spectrometer, which detects
hydrogen, which with oxygen makes up water.
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- The Mars Express data amounts to a confirmation, because
it arrives at the same conclusion but by a different technique: its Omega
spectrometer analyses visible and infrared light rather than the gamma
part of the energy spectrum.
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- Rickard Lundin, from the Swedish Institute of Space Science,
is studying how the Sun is eroding the Martian atmosphere with an instrument
called the Energetic Neutral Atoms Analyser.
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- "It shows us the 'planetary wind' which essentially
describes water escape - but in an indirect way because what we see coming
[off Mars] is oxygen and the oxygen is most likely coming from water."
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- Mars Express arrived at the Red Planet on 25 December.
It operates from a polar orbit that takes it between 300 and 11,000 km
from the planet's surface.
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- European scientists want the mission to: map the mineral
composition of the surface at 100-m resolution map the composition of the
atmosphere and determine its global circulation determine the structure
of the sub-surface to a depth of a few kilometres determine the effect
of the atmosphere on the surface and determine the interaction of the atmosphere
with the solar wind At the heart of the mission is the desire to understand
the history and current state of water on the planet which may say something
about the presence of life - currently or in the far-distant past.
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- So far, Mars Express has performed flawlessly. The one
disappointment has been the loss of its lander probe, Beagle 2.
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- The British-built robot has not been heard from since
it fell through the Martian atmosphere on Christmas Day.
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- © BBC MMIV
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- http://news.bbc.co.uk/2/hi/science/nature/3422841.stm
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- In Pictures:
- Close-Ups Of Mars
- http://news.bbc.co.uk/2/hi/science/nature/3423301.stm
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