WASHINGTON (Reuters) - International space missions have found ice on the moon and more evidence of ice on Mars -- good news for future settlements and also for scientists looking for extraterrestrial life.
Four reports published in Friday's issue of the journal Science show clear evidence of water, likely frozen, on the desert surfaces of both the Moon and Mars.
The U.S. space agency NASA said its Moon Mineralogy Mapper, or M3, found water molecules all over the moon's surface. The M3 instrument was carried there last October by the Indian Space Research Organization's Chandrayaan-1 spacecraft -- India's first space mission.
"Water ice on the moon has been something of a holy grail for lunar scientists for a very long time," said Jim Green, director of the Planetary Science Division at NASA in Washington.
"When we say 'water on the moon,' we are not talking about lakes, oceans or even puddles. Water on the moon means molecules of water and hydroxyl (hydrogen and oxygen) that interact with molecules of rock and dust specifically in the top millimeters of the moon's surface," Carle Pieters of Brown University in Rhode Island said in a statement.
Jessica Sunshine of the University of Maryland and colleagues used infrared mapping from the Deep Impact spacecraft to show water all over the moon. Roger Clark of the U.S. Geological Survey and colleagues used a spectrometer -- which breaks down light waves to analyze elements and chemicals reflecting them -- from the Cassini spacecraft to identify water.
"This water on the moon appears to be bound up with minerals such that it is stable in the airless and low-gravity environment of the moon," Marc Norman of Australian National University in Canberra said in a statement. "So we won't be able to pump it like groundwater, but will have to collect fairly large volumes of lunar soil, then extract and store the water for use."
In the fourth report, NASA said its Mars Reconnaissance Orbiter spotted ice at five new Martian craters, likely kicked up by meteor impacts.
"We now know we can use new impact sites as probes to look for ice in the shallow subsurface," Megan Kennedy of Malin Space Science Systems in San Diego, who worked on the study, said in a statement.
"This ice is a relic of a more humid climate from perhaps just several thousand years ago," added Shane Byrne of the University of Arizona.
"This is a real water resource," said Louis Friedman, executive director of the Planetary Society.
There is now no dispute that water exists on the surface of Mars -- robot explorers have found ice. There is also evidence that water may still seep to the surface from underground, although it quickly disappears in the cold, thin atmosphere of the red planet.
Planetary scientists have also seen what could be the shores of giant rivers and seas on Mars.
"Having any water or hydroxyl in the sunlit areas of the Moon is as surprising as it is intriguing," added the planetary society's Bruce Betts. "Will such results turn out to be the tip of the iceberg, or will the moon remain a dry desert with slightly more moisture than we thought?"
Editing by Chris Wilson