National Aeronautics and Space Administration Logo
Follow this link to skip to the main content NASA Banner
Solar System Exploration
News & Events
Where Did Martian Water Go?
Where Did Martian Water Go?
27 Sep 2004
(Source: European Space Agency)

http://www.esa.int/SPECIALS/Mars_Express/SEM75BADFZD_0.html

Mars Express latest findings give hints about water loss in the Martian atmosphere

European Space Agency
27 September 2004

Recent results from the ASPERA-3 instrument on board Mars Express confirm that a very efficient process is at work in the Martian atmosphere which could explain the loss of water. Water is believed to have once been abundant on the Red Planet. Professor Rickard Lundin, leader of the ASPERA-3 team, describes these findings in a paper published in the latest issue of "Science".

Mars is bombarded by a flood of charged particles from the Sun, commonly called the "solar wind" and consisting of electrons and alpha particles. The solar wind erodes the atmosphere of Mars, and is believed to have stripped away a large amount of water that was present on the planet about 3.8 billion years ago. Geological evidence, as recently confirmed by images from the High Resolution Stereo Camera (HRSC) onboard Mars Express, indicates that water flows and even an ocean in the Northern hemisphere shaped the surface of Mars.

Today, water still exists on the Red Planet, but less than in the past. Observations made earlier this year by the OMEGA instrument on Mars Express showed that Mars has vast fields of perennial water ice, stretching out from its south pole.

The ASPERA-3 instrument on board Mars Express aims to answer the question of whether the solar wind interaction with the upper atmosphere of Mars contributes to the depletion of water. It is measuring a process called "solar wind scavenging", or the slow "invisible" escape of volatile gases and liquid compounds which make up the atmosphere and hydrosphere of a planet. Using plasma spectrometers and a special imager to detect energetic neutral atoms, ASPERA-3 is making global and simultaneous measurements of the solar wind, the inflow of energetic particles, and also the "planetary wind", which is the outflow of particles from the Martian atmosphere and ionosphere.

Aspera 3 has established that the solar wind penetrates through the ionosphere and very deeply into the Martian atmosphere down to an altitude of 270 kilometres. This seems to be the reason for the acceleration processes that cause the loss of atmosphere on Mars.

Notes for editors

A paper describing the results, by Professor Rickard Lundin and his collaborators was published last Friday in "Science". Professor Rickard Lundin and Dr Stas Barabash from the Swedish Institute for Space Physics in Kiruna, Sweden, are the leading scientists responsible for the ASPERA-3 instrument, which results from collaboration with 15 other research groups in ten different countries.

News Archive Search  Go!
Show  results per page
 
 
Awards and Recognition   Solar System Exploration Roadmap   Contact Us   Site Map   Print This Page
NASA Official: Kristen Erickson
Advisory: Dr. James Green, Director of Planetary Science
Outreach Manager: Alice Wessen
Curator/Editor: Phil Davis
Science Writer: Autumn Burdick
Producer: Greg Baerg
Webmaster: David Martin
> NASA Science Mission Directorate
> Budgets, Strategic Plans and Accountability Reports
> Equal Employment Opportunity Data
   Posted Pursuant to the No Fear Act
> Information-Dissemination Policies and Inventories
> Freedom of Information Act
> Privacy Policy & Important Notices
> Inspector General Hotline
> Office of the Inspector General
> NASA Communications Policy
> USA.gov
> ExpectMore.gov
> NASA Advisory Council
> Open Government at NASA
Last Updated: 27 Sep 2004