There is a lot more water on the
moon than previously believed, according to an analysis of
NASA data being published Friday, a finding that may bolster
the case for a manned base on the lunar surface.
The discovery grew out of an
audacious experiment last year, when the National
Aeronautics and Space Administration slammed a spent-fuel
rocket into a lunar crater at 5,600 miles an hour, and then
used a pair of orbiting satellites to analyze the debris
thrown off by the impact. They discovered that the crater
contained water in the form of ice, plus a host of other
resources, including hydrogen, ammonia, methane, mercury,
sodium and silver.
NASA announced its groundbreaking
discovery of lunar water last November. Now, a more detailed
analysis of the data—the subject of six research papers
being published in the journal Science—concludes that there
is a lot more water on the moon than anyone expected, about
twice the concentrations seen in the Sahara Desert.
"It's really wet," said Anthony
Colaprete, co-author of one of the Science papers and a
space scientist at NASA Ames Research Center at Moffett
Field, Calif. He and his colleagues estimate that 5.6% of
the total mass of the targeted lunar crater's soil consists
of water ice. In other words, 2,200 pounds of moon dirt
would yield a dozen gallons of water.
The presence of water doesn't make
it more likely that there ever was life on the moon, as the
location studied is among the coldest in the solar system.
But the large quantity boosts the case for a manned lunar
base from which to launch other interplanetary adventures.
Water is crucial because its components, hydrogen and
oxygen, are key ingredients for rocket fuel. Oxygen can also
be extracted from water to make breathable air.
Finding a water source on the moon
has long been a dream, because it could save on the expense
of transporting it from earth. A bottle of water on the moon
would run about $50,000, according to NASA, because that is
what it costs, per pound, to launch anything to earth's
Scientists have discovered significant amounts of
water on the moon, a finding that may bolster the
case for establishing a manned base on the lunar
surface. Lee Hotz has details. Plus, who owns the
moon? And why stocks were so volatile today.
The U.S. likely won't be involved
in manned voyages to the moon anytime soon. President Barack
Obama recently canceled a NASA program to return astronauts
to the lunar surface a decade from now. The agency, however,
is working on the grander, longer-term prize of a manned
trip to Mars.
But other countries are gearing up.
China has pledged to land astronauts on the moon by 2025,
and India has plans to do the same by 2020. Japan wants to
establish an unmanned moon base in a decade, potentially
setting the stage for a manned mission later. So far, only
the U.S. has sent astronauts to the moon.
NASA chose its impact site
carefully. Because of the tilt of the moon's axis, the
floors of large craters at either pole haven't received
direct sunlight for billions of years. NASA's target was a
crater, Cabeus, near the southern pole.
Cabeus is a cosmic trap. Any
material that lands there sticks. "There's almost no energy
to warm up the molecules, so that they can't bounce off
again," said G. Randall Gladstone, co-author of one of the
Science papers and a planetary scientist at the nonprofit
Southwest Research Institute in San Antonio.
Dr. Gladstone and others believe
that Cabeus contains cosmic material that has accumulated
over a billion years or more. Scientists know that most of
the moon is almost entirely dry. But some remote
observations had suggested that water might be present at
cold-trap regions of the moon.
The quantity of water discovered
was 50% greater than NASA's initial estimates. Other
measurements suggest there's even a "lunar permafrost"
covering about 30% of the southern polar region of the moon,
with ice lying just below the surface.
In its search for lunar water, NASA
launched an Atlas V rocket stacked with an upper-stage
rocket known as Centaur. Above it sat the Lunar Crater
Observation and Sensing Satellite, or LCROSS, roughly the
size of a Volkswagen Beetle. Atop that sat another
satellite, the Lunar Reconnaissance Orbiter, or LRO.
The LRO went into moon orbit.
Centaur eventually flew toward the Cabeus crater, followed
by a hurtling LCROSS. Drained of fuel, Centaur was now the
equivalent of an empty soda can 36 feet tall.
It slammed into the crater's
"fluffy, snow-covered dirt," scientists said, spewing at
least 8,800 pounds of debris, dust and vapor. LCROSS's
instruments took measurements on the quantity of water vapor
and ice in the plume, then smashed into the moon as well.
The LRO satellite, meanwhile,
orbited 30 miles above the moon. Its main task—which it
continues to do today—was to create a three-dimensional map
of the moon's surface, but it collected data on the impact
plume as well.
A surprising amount of the Cabeus
dirt, about one-fifth, is a mix of different elements and
volatile compounds, including water. The rest is made from
the typical components of moon rock, including feldspar and
How NASA Found Water on the Moon
The scientists also found molecular
hydrogen in the soil. "That's interesting because if you
want to make rocket fuel you could heat up the soil and
hydrogen would come pouring out," said Dr. Gladstone.
Write to Gautam