'Wet' asteroids could serve as interplanetary rest areas
The recent discovery of an asteroid wrapped in ice suggests that astronauts could stop at space rocks for washing and refueling.
The recent discovery of an asteroid wrapped in a layer of water ice has revived the possibility that some space rocks would be great potential pit stops – as well as destinations – for manned or robotic exploration missions.Skip to next paragraph
In Pictures Asteroids
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If a space destination has water, that means astronauts traveling there could potentially use it for drinking and washing. But much more importantly, the water could be broken down into its component parts (hydrogen and oxygen) to make rocket fuel, experts say.
"Water is the main component in how you might make propellants," said Jerry Sanders, leader of in-situ resource utilization at NASA's Lunar Surface Systems Office at the Johnson Space Center in Houston. "If you're going to go repeatedly to an asteroid, then the ability to basically start setting up gas stations could be extremely beneficial."
Researchers announced last week that they had found definitive proof of frozen water, along with organic compounds, coating the surface of the large asteroid 24 Themis in the asteroid belt between Mars and Jupiter. Previously, scientists had believed that asteroids there were too close to the sun to harbor water without it evaporating away.
In addition to the practical benefit, water means that the site may potentially be habitable to life, which boosts the asteroid's scientific appeal as well. Although there's no sign yet that this or any other spot in the universe hosts extraterrestrials, the presence of water is the first thing researchers look for when scouting out where potential alien neighbors may reside.
President Barack Obama has set the goal of sending astronauts to a nearby asteroid by 2025. But those close space rocks would likely not have water ice since they would be even closer to the sun than the asteroid belt.
Space gas stations
Even small amounts of water on the surface of a planet or asteroid can bring big benefits for visiting missions.
For manned missions, a source of water for drinking and for extracting oxygen to breathe would be good as a backup, though hopefully closed-loop life-support systems could recycle most of the initial supplies, Sanders said. The real payoff of water would be in the possibility of using it to make fuel, said he added.