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| A panoramic view of the surface of Mars from the Curiosity rover. Mount Sharp can be seen in the distance (NASA) |
For lifeless chemical compounds to organize themselves into something alive, scientists generally
agree, three sets of things must be present:
■ Standing water and an energy source.
■ Five basic elements: carbon, oxygen, hydrogen, phosphorus and nitrogen.
■ And time, lots of time.
In its search for environments where life might have started on Mars, the Curiosity rover has found the standing water, the energy and the key elements with the right atomic charges. As a result, scientists have concluded that at least some of the planet must have been habitable long ago.
But the period when all conditions were right was counted in hundreds to thousands of years, a very small opening by origin-of-life standards.
That has now changed. John P. Grotzinger of Caltech, the project scientist for the mission, reported at a news conference on Monday that the rover’s yearlong trek to Mount Sharp provided strong new evidence that Gale Crater had large lakes, rivers and deltas, on and off, for millions to tens of millions of years. The geology shows that even when the surface water dried up, plenty of water would have remained underground, he said.
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