When NASA scientists sent two rovers to Mars, they thought the mission might last three months. "In my secret heart of hearts, I was hoping to stretch it out to six months," says Stephen Squyres, one of the scientists. Today, more than a year later, the rovers are still going strong!
Spirit and Opportunity continue to roam the Red Planet and send back extremely clear pictures as well as other data. At the same time, two orbiting crafts, Mars Global Surveyor and Europe's Mars Express, are taking supersharp long-distance images. Earthlings are getting a better look at Mars than they had ever hoped.
Exploring the Red Planet
On January 3, 2004, Spirit touched down on Mars. Opportunity followed a
few weeks later, landing on the opposite side of the planet. Both rovers
got to work, digging into the soil and drilling into rocks and sending
back data about their findings. They were looking for signs of water.
As luck would have it, one rover landed inside a small crater created long ago by the impact of a meteorite. The walls of the crater gave Opportunity a look at ancient layers of Mars's crust. Scientists think the layers were created by a shallow lake that had periodically dried up and refilled. This information confirmed what scientists had long believed: Water once flowed on Mars. Water could have nourished Martian life.
The rovers' probing has revealed information that continues to surprise researchers. "Not only can we say there was water," Squyres told TIME, "but we've made substantial strides in understanding what conditions were actually like."
The presence of water on Mars doesn't prove that life once thrived there, but it's a promising sign that it could have. Spirit has uncovered soil that is more than half salt, adding to the evidence that the planet had oceans in the past. The rovers also have detected methane gas in the Martian air. Methane is produced by living organisms. If bacteria still live under Mars's surface, they could be releasing the gas.
Revealing More Secrets
The discoveries keep coming. This month, the Mars Express orbiter found
what may be huge slabs of ice from a frozen sea buried under a thick
layer of dust.
Spirit has already unearthed the first meteorite found on another world. Both rovers will continue to lay bare the secrets of the Red Planet. Spirit recently climbed a hill, looking for new places to explore. Opportunity is heading south toward an area that may give scientists a look at deeper layers of rock and soil than they have seen so far.
The scientists are making the most of each Martian moment. "I have no idea how much longer (the rovers) will last," Squyres says. "So you plan for the long term--but each day you drive like there's no tomorrow."