“We got it.” Those words from the Jet Propulsion Laboratoy (JPL) in California, mission control center for the Mars Exploration Rover (MER) Spirit, have opened a period that will prove to be the most exciting yet in humanity’s quest to understand the solar system and Earth’s mysterious neighbour.
Late on the night of January 3, tension and excitement were both high at the JPL as Spirit safely went through all its landing sequences, from entry, descent, and landing. Now, just over a week later, the rover already has its arm and all six of its wheels free, has cut the cord connecting the rover to the lander, and is almost ready to roll off the landing platform, after which it will be free to explore uncharted Martian vistas.
While the last Mars rover was about the size of a computer monitor, Spirit stands about five feet tall. The rover will explore the Gusev crater, which is the size of Connecticut and was probably once a Martian lake. “There’s not much doubt: this site contained a body of liquid water, at least for some amount of time,” says Jim Garvin, NASA’s lead scientist for Mars Exploration. It is thought that sediments may have been deposited into the crater by water entering the lake from a channel system.
The rover, equipped with a robotic arm and a drilling tool, will have the capability to grind away surface dust and will be able to analyze rocks for minerals that form as water dries up, such as gypsum, familiar on Earth, and calcium magnesian sulfate. Minerals of carbonate, known to be often produced by life and nearly always a sign of water, may be discovered.
The rover, designed to survive for at least three months, will be able to move to interesting rocks and deposits at a speed of one km/day. At the end of the month Spirit will be joined by its twin rover Opportunity, which will land nearly halfway around the planet so that day and night there will be rovers roaming the Martian surface.
Opportunity is nearing the planet and will arrive by January 25 on a region known as Meridiani Planum, which contains exposed deposits of a mineral called gray hematite that forms most often under long-term watery conditions. Scientists may find proof for a past lake or hot spring, ideal conditions for life.
Unfortunately this unprecedented period of discovery began with a disaster when the British Mars lander, Beagle 2, failed to make contact with Earth. Beagle 2 had successfully detached from the orbiter Mars Express five days earlier, but contact was never made after the lander entered the Martian atmosphere.
However, Mars Express was successfully placed into a stable orbit from where it will perform studies on the planet’s atmosphere, surface, and crust down to a few kilometers below the surface. Since NASA’s Mars Odyssey confirmed the presence of frozen water buried under dry ice (frozen carbon dioxide), the European Space Agency’s Mars Express hopes to continue these investigations.
These investigations into the existence of life (or at least the ingredients necessary to sustain life) on Mars are absolutely essential, regardless of the result, explains Ivan Semeniuk, a science commentator for Discovery. They will help to define the boundary of the “lifespace” in the universe, and the habitable zone of our solar system.
“Of all the solar system planets, Mars has the climate most like that of Earth. Both are sensitive to small changes in orbital parameters,” said planetary scientist Dr. James Head of Brown University. “Now we’re seeing that Mars, like Earth, is in a period between ice ages.” As Mars is so similar to Earth, information on its past will help us understand our own planet’s past.
But more than that, Semeniuk explains, Mars is special because it is more like a “real” place than any other planet in the solar system, save Earth, with a landscape, a horizon and a sky. When you look at images of Mars, you “feel like you could step into the frame and start walking around.”
