NASA's far-flung space robots keep findings signs of water

Robotic explorers have found signs of long-lost water on Mars and extensive ice still present on the dwarf planet Ceres — evidence that water truly is almost everywhere we look.

The results were announced at the fall meeting of the American Geophysical Union — the world's largest gathering of Earth and space scientists. There, NASA scientists discussed the results from several of the dozen space probes currently exploring the universe beyond our planet.

The rover Curiosity has been trundling across the Martian landscape for more than four years. But recently, the plucky robot rolled onto a patch of ground with veins of calcium sulfate, in the form of the mineral gypsum, running through it. Hiding within those veins was the element boron, which usually appears only in once-flooded sites where the water has evaporated away.

According to scientists at the Los Alamos National Laboratory, the discovery in Mars's Gale Crater suggests that there was once liquid water on the Red Planet — and that the water was habitable. The calcium sulfate and boron could only precipitate out of water that was between 32 and 140 degrees Fahrenheit and was not too acidic.

This was the first discovery of boron on Mars, and the latest finding suggesting that Mars used to be much wetter, warmer and far less hostile than it is now.

In the asteroid belt between Mars and Jupiter, the space probe Dawn has been surveying the rocky, icy body known as Ceres. The dwarf planet is the largest thing in the asteroid belt, and it's pocked with craters deep enough that their interiors are cast in permanent shadow.

Dawn scientists announced at AGU that they have new evidence that some of Ceres's craters act as cold traps that accumulate pockets of permanent water ice. In addition, the protoplanet has huge amounts of ice just below its rocky surface and may even have a slushy ocean of liquid water in its interior.

This means that Ceres is less like fellow asteroid-belt inhabitant Vesta, a dry rocky world that Dawn visited before the current phase of its mission, than it is like the icy moons that exist in the outer part of the solar system.

"It's pointing toward Ceres being a really interesting object," Carol Raymond, Dawn's deputy principal investigator, said at a news conference. "Similar to Europa or Enceladus in terms of its habitability potential."

Europa and Enceladus, moons of Jupiter and Saturn, respectively, are thought to contain liquid water oceans in their interiors and are considered prime targets in the search for life beyond Earth.