Ice, ice, baby. NASA is looking for it in our own backyard again - this time on the moon.
Just two days after the Jet Propulsion Laboratory announced the discovery of a giant, previously invisible ring around Saturn, the space agency is looking for another hidden gem in our solar system - evidence of water on the dark side of the moon - and they're pulling out all the stops to find it.
Well, technically, it's only two stops being pulled. The plan, see the video walkthrough here, is to basically ram an Atlas V rocket into the crater Cabeus on the moon's south pole so a probe can analyze the debris thrown into the the sky for evidence of water. Then that probe wil smash into the moon's surface to create a debris field for Eartbound and orbital observers to study.
Here's how the obviously giddy NASA folks explain the process:
Just imagine. A spaceship plunges out of the night sky, hits the ground and explodes. A plume of debris billows back into the heavens, leading your eye to a second ship in hot pursuit. Four minutes later, that one hits the ground, too. It's raining spaceships!
And you thought science wasn't fun? It's like a galactic smashup derby up there! But why go to the trouble of finding what at best would be evidence of water on a molecular level? Moon Base Alpha, baby!
A discovery of ice could give future explorers a vital supply of drinking water or, by breaking it down into hydrogen and oxygen, air for breathing or rocket fuel, according to the rocket scientists.
NASA researchers will analyze the data and compare notes with other observatories to confirm if water was detected in the plume, said Jonas Dino, a spokesman for NASA. Photos of the impact will be released within hours of the event, while a report on the findings will take months to prepare, he said.
"These craters have floors that have not seen sunlight for perhaps billions of years," said Dino, who works at NASA's Ames Research Center in Moffett Field, California. "So it would be one of those places where we would have ancient ice that we can possibly sample in the future to see how the solar system was formed."
The mission is dubbed LCROSS, for Lunar CRater Observation and Sensing Satellite, seen to the right in an artist rendering. The rocket propelling the satellite will detach first and smash into the moon's surface, creating a crater about 20 meters wide and 3 meters deep and disturbing about 250 metric tons of lunar dust, NASA said. The cloud will be visible to some Earth observers with telescopes of 10 inches to 12 inches and larger. Or, you can watch a couple of other ways, says NASA:
First, turn on NASA TV. The space agency will broadcast the action live from the Moon, with coverage beginning Friday morning at 5:15 a.m. Central time. The first hour or so, pre-impact, will offer expert commentary, status reports from mission control, camera views from the spacecraft, and telemetry-based animations.
The actual impacts commence at 6:30 a.m. The Centaur rocket will strike first, transforming 2200 kg of mass and 10 billion joules of kinetic energy into a blinding flash of heat and light. Researchers expect the impact to throw up a plume of debris as high as 10 km.
Close behind, the LCROSS mothership will photograph the collision for NASA TV and then fly right through the debris plume. Onboard spectrometers will analyze the sunlit plume for signs of water (H2O), water fragments (OH), salts, clays, hydrated minerals and assorted organic molecules.
We mere mortals stuck back home have a fighting chance of watching the show, though with fairly common telescope equipment:
"We expect the debris plumes to be visible through mid-sized backyard telescopes - 10 inches and larger," says Brian Day of NASA/Ames. Day is an amateur astronomer and the Education and Public Outreach Lead for LCROSS. "The initial explosions will probably be hidden behind crater walls, but the plumes will rise high enough above the crater's rim to be seen from Earth."
The Pacific Ocean and western parts of North America are favored with darkness and a good view of the moon at the time of impact. Hawaii is the best place to be, with Pacific coast states are a close second, says NASA. Any place west of the Mississippi River, however, is a potential observing site.
When the plumes emerge from Cabeus, they will be illuminated by sunshine streaming over the polar terrain. The crater itself will be in the dark, however, permanently shadowed by its own walls. "That's good," says Day. "The crater's shadows will provide a dark backdrop for viewing the sunlit plumes."
LCROSS is part of NASA's $120 billion plan to return to the moon by 2020 as a step toward the eventual goal of a manned mission to Mars and comes the just as the 40th anniversary of the first lunar landing was celebrated this summer.
Dating to at least 1999, when a lunar mission detected water signatures from the supposedly bone-dry moon, NASA scientists have pondered whether ice left from comet impacts may have pooled and cooled in the permanently shaded potholes - probably strangers to sunlight for billions of years - dotting the lunar poles. In 2004, when the Bush administration pushed for moon bases, glaciers hidden in those craters looked attractive as water and fuel sources for future moon colonists.
Last month, Science magazine reported evidence of water migrating out of the lunar soil in the solar wind, or streams of gas particles from the sun, and perhaps some of the water ended up in those shaded craters.
The discovery has potential, though. Future astronauts might conceivably wring enough water from not-completely-desiccated lunar "soil" to drink or even to fuel their rockets. Equally enticing, the water seems to be on its way to the poles, where it could be pumping up subsurface ice deposits that would be a real water bonanza.
There is the chance this is a big bang for nothing. That 1999 prospecting expedition didn't turn up so much as drop of hope. The year before, the probe had detected hydrogen at the moon's polar region.
"Water on the moon has haunted us for years," says William Hartmann of the Planetary Science Institute. "It's all part of humanity's quest to understand our nearby cosmic environment."