|Perspective view. Solis Planum images were taken during orbit 431 in May 2004 with a ground resolution of approximately 48 meters per pixel. The displayed region is located south of Solis Planum at longitude 271° East and latitude of about 33° South.
Credit: ESA/Mars Express
Six years ago, then NASA Associate Administrator Wesley Huntress, Jr., stated , "Wherever liquid water and chemical energy are found, there is life. There is no exception." Few opportune years like 2004 have presented astrobiology with as many remarkable vistas and fresh perspectives on this fundamental triad of water, chemical energy and life.
Consider this year's accomplishments of those dedicated to searching for life in the universe.
Landing on Mars not once, but twice. Then finding evidence for water on opposite sides of the red planet. Picking up what appears to be methane signals in the martian atmosphere, one of the residues that might prove one day to be the product of underground biology. Scientists began to discuss seriously what colonization strategies make sense.
Setting off to explore the even richer atmosphere of the Earth-like moon, Titan. Spiraling into orbital capture around Saturn and photographing its majestic rings.
Flying through the tail of a comet and heading home after collecting the first extraterrestrial samples from such dusty iceballs. Launching the Deep Impact probe to smash into a comet and watch how the dust and ice get kicked up.
Filling the astronomy catalogs with well over a hundred new planets, including what may prove to be the first visible exoplanet. Finding some nearby candidates that might occupy temperate locations or safely orbit Sun-like stars.
Witnessing the once-per-century passage of our neighboring Venus across the face of the Sun. The MESSENGER probe took off on its decade long tour of the inner solar system to orbit Mercury.
Discovering the largest planetoids beyond Pluto among those outer nurseries where only comets visit.
The editors of Astrobiology Magazine revisit the highlights of the year and where possible point to one of the strongest lineups ever for beginning a new turn of the calendar. Between the marathon still being run by the twin Mars rovers and the expected descent to Saturn's moon, Titan, next year promises no letdowns.
|A topview, high resolution image looking down on Eos Chasma, part of Valles Marineris
Credit: ESA/Mars Express
Number eight on the countdown of 2004 highlights was the assembly of the Mars satellite constellation. With two surface rovers active, even more satellites circumnavigated overhead. For the first time in planetary exploration, data relays of unprecedented volume and frequency could be assembled, stored and transmitted back to Earth. Two of these satellites have orbited for years, the Mars Global Surveyor and Odyssey. The European mission, Mars Express, joined with the constellation to study the atmosphere and provide high-resolution images of the surface features and topography.
Mars Express is performing the most detailed and complete exploration of Mars ever done. From the start of January to the middle of February, Mars Express produced a total of 18 strips of pictures in 100 orbits of Mars. In general, one orbit produces an image with a length of over 250,000 lines.
When searching for water, for instance, Mars Express is conducting the most thorough search so far: from several kilometers below the ground, and up into the atmosphere. Before entering martian orbit, the cruise took just over six months. Mars Express travelled at an average speed of about 10 kilometers per second (around 2100 miles per hour) and covered a distance of about 400 million kilometers (240 million miles).
From orbit, Mars Express is scanning the surface and atmosphere of the planet with seven instruments. In particular it will:
- search for signs of water down to a few kilometres underground;
- map the Martian surface more accurately than ever before (in colour and stereo);
- determine the detailed composition of the surface;
- determine the composition and circulation of the atmosphere;
- study the interaction of the solar wind with the planet.
Mars Express's orbiter will operate for a whole Martian year (687 Earth days). It is expected that the mission will be extended by another Martian year. After the mission, the Mars Express orbiter will simply keep orbiting the planet for at least 50 years. Then it will probably burn up in Mars's atmosphere. This will also ensure that debris will not pollute the planet's surface. Many of Mars Express elements will be used for Venus Express, and probably other missions in the future.
- Mars Reconnaissance Orbiter (MRO) launch, Mars Orbiter to collect high-resolution, 1-meter, images in stereo-view of Mars
- European Venus Express, Venus Orbiter for two-year nominal mapping life [486 days, two Venus year]
- New Horizons, Pluto and moon Charon flyby, mapping to outer solar system cometary fields and Kuiper Belt
- Dawn, Asteroid Ceres and Vesta rendezvous and orbiter, including investigations of asteroid water and influence on meteors
- Kepler, Extrasolar Terrestrial Planet Detection Mission, designed to look for transiting or earth-size planets that eclipse their parent stars [survey 100,000 stars]
- Europa Orbiter, planned Orbiter of Jupiters ice-covered moon, Europa, uses a radar sounder to bounce radio waves through the ice
- Japanese SELENE Lunar Orbiter and Lander, to probe the origin and evolution of the moon
- Japanese Planet-C Venus Orbiter, to study the Venusian atmosphere, lightning, and volcanoes.
- Mars Scout mission, final selections August 2003 from four Scouts: SCIM, ARES, MARVEL and Phoenix
- French Mars Remote Sensing Orbiter and four small Netlanders, linked by Italian communications orbiter
- BepiColumbo, European Mercury Orbiters and Lander, including Japanese collaborators, lander to operate for one week on surface
- Mars 2009, proposed long-range rover to demonstrate hazard avoidance and accurate landing dynamics
Related Web Pages
2003: Year in Review
Solar System Exploration Survey
Mars Opportunity Rover
Mars Spirit Rover
Planet Ten: Beyond Pluto?