This story took away one of my childhood (and grownup) dreams:
NASA’s Mars Global Surveyor spacecraft, in orbit around Mars, has been measuring the glow of infrared light from the rocks below, looking for patterns of colors that identify different minerals. In particular, scientists have been interested in minerals known as carbonates, which form only in the presence of liquid water. On Earth, the white cliffs of Dover in England are a notable example of carbonates.
In today’s issue of the journal Science, the researchers who run the infrared instrument report that Global Surveyor has detected small concentrations of carbonates in Martian dust, 2 percent to 5 percent by weight, but none of the large deposits that would probably form at the bottom of a lake or an ocean.
“I would say it’s extremely unlikely Mars had large bodies of warm, standing water that were exposed to the atmosphere for a long period of time,” said Dr. Philip R. Christensen, a professor of geological sciences at Arizona State University and senior author of the article. “It’s reasonably unlikely that massive carbonates exist and we haven’t seen them.”
Then again, it’s not like we weren’t going to have to terraform the place before establishing permanent settlements. But finding the water to do so just got that much harder.