Ice on Mars south pole

Mars Express reveals frozen water

One of the main targets of the Mars Express mission is to discover the presence of water in one of its chemical states. Through the initial mapping of the South polar cap on 18 January, OMEGA, the combined camera and infrared spectrometer, has already revealed the presence of water ice and carbon dioxide ice.

This information was confirmed by the PFS, a new high-resolution spectrometer of unprecedented accuracy. Its data also show that the carbon oxide distribution is different in the northern and southern hemispheres of Mars.

The MaRS instrument, a sophisticated radio transmitter and receiver, emitted a first signal successfully on 21 January that was received on Earth through a 70-metre antenna in Australia after it was reflected and scattered from the surface of Mars. This new measurement technique allows the detection of the chemical composition of the Mars atmosphere, ionosphere and surface.

ASPERA, a plasma and energetic neutral atoms analyser, is aiming to answer the fundamental question of whether the solar wind erosion led to the present lack of water on Mars. The preliminary results show a difference in the characteristics between the impact of the solar wind area and the measurement made in the tail of Mars.

Another exciting experiment was run by the SPICAM instrument (an ultraviolet and infrared spectrometer) during the first star occultation ever made at Mars. It has simultaneously measured the distribution of the ozone and water vapour, which has never been done before, revealing that there is more water vapour where there is less ozone.



Reull Vallis in the Hellas basin 41° South 101° East.
The landscape is seen in a vertical view, North is at the top.


This picture was taken by the High Resolution Stereo Camera (HRSC) onboard ESA's Mars Express orbiter, in colour and 3D, in orbit 18 on 15 January 2004 from a height of 273 km.

The area is 100 km across, and shows a channel
(Reull Vallis) once formed by flowing water.