The exploratory mission of the Mars Express—whose name refers to the quickness of its design and manufacture and to the short relative distance it traveled between the Earth and Mars due to careful timing of the mission—originally consisted of the Mars Express Orbiter and the Beagle 2. On June 2, 2003, the spacecraft was launched from Baikonur Cosmodrome in Kazakhstan powered by a Soyuz-Fregata rocket. Unfortunately, after entering Mars orbit in December 2003 and deploying from the orbiting Mars Express Orbiter the Beagle 2 was lost on December 25, 2003, when it failed to communicate to the already-orbiting NASA Mars Odyssey. The ESA Mars Express team declared the Beagle 2 officially lost on February 6, 2004.

The Mars Express Orbiter continued its important science mission without Beagle 2. One of its first indications that Mars might possess underground water came in November 2005 when the MARSIS (Mars Advanced Radar for Subsurface and Ionosphere Sounding) experiment found the presence of underground water ice. MARSIS has the ability to remotely sense and record subsurface reflections; that is, it can analyze the composition of the ground beneath the surface of Mars (down to about five kilometers [three miles]), specifically with regards to the presence of frozen water.

Then, in 2007, ASPERA (Analyzer of Space Plasmas and Energetic Atoms), another instrument onboard the Mars Express Orbiter, found that the rate of water loss on Mars is much lower than believed. Dr. Stanislav Barabash of the Swedish Institute of Space Physics (Kiruna, Sweden) headed a team whose research from the Mars Express Orbiter found the entire planet only loses about 20 grams of oxygen and carbon dioxide each second—a rate that was only about 1% of what was previously believed to be lost. If Barabash’s discovery proves to be correct, then only a relatively miniscule amount of water and carbon dioxide would have disappeared over the past three to four billion years.

Barabash’s team does not know what happened to this water. They surmise that it might have been removed through one or more currently unproven processes (such as dramatic asteroid and comet impacts, solar winds, or magnetic storms). Or, they also think that a possible scenario is that the water may still be on Mars, only stored underground. In fact, Barabash reported to New Scientist that: “We are talking about huge amounts of water. To store it somewhere requires a really big, huge reservoir.”

Barabash and his colleagues report their findings on January 26, 2007, in Science magazine.

Scientists know that when Mars was a much younger planet it contained large amounts of liquid. However, scientists do not know where all of that liquid went. Mars Express and other spacecraft sent to explore Mars may soon find out. Future manned missions to Mars may find plenty of water to support humans and to provide hydrogen and oxygen for rocket fuel. Whether that occurs or not will only be found out sometime in the future—as more information is carefully and deliberately retrieved from Mars.

Information about the Mars Express mission is found at ESA’s site: http://www.esa.int/SPECIALS/Mars_Express/index.html.

Information about the Mars Express mission can also be found at NASA’s site: http://marsprogram.jpl.nasa.gov/express/.

The Home Web page of the Swedish Institute of Space Physics is located at: http://www.irf.se/.

{moscomment}