I'm Shirley Griffith.
And I'm Steve Ember with
EXPLORATIONS in VOA Special English. This week, we tell about the discovery of water
on the moon.
learn where scientists found one of the basic substances necessary for life. And we hear about the newly improved Hubble
The moon appears to be a
dry and dead place. Scientists have long
believed that Earth's satellite lacks the ability to hold water near its
surface because it has no atmosphere. So
the announcement by the United States space agency shocked many in the
CARLE PIETERS: "Widespread water has been detected on
the surface of the moon."
was Carle Pieters, a professor at Brown University, in
Providence, Rhode Island. She is lead
investigator for a NASA team studying the lunar findings.
NASA scientists discovered water molecules mainly in the moon's extreme northern
and southern areas. The researchers
note, however, that they could also be seeing evidence of another molecule,
is the combination of one hydrogen atom and one oxygen atom. Water is made of one oxygen atom and two
hydrogen atoms. The NASA team still is
not sure how much of what they have found is water and how much is hydroxyl.
Instruments on three separate spacecraft have now shown
evidence of lunar water. NASA's Moon Mineralogy
Mapper provided the most recent evidence.
It was one of eleven scientific devices carried by the Chandrayaan-One
spacecraft of the Indian Space Research Organization.
The mapper is a spectrometer, a
device that measures reflected light wavelengths. It is able to show scientists what an object
is made of from great distances. Similar
devices on NASA's Cassini and Epoxi spacecraft also reported the presence of
water. But those observations were made
years ago and NASA scientists had not trusted the results without clear
confirmation. Now, Mizz Pieters calls
the new results completely conclusive.
The findings were published in the journal Science.
Moon Mineralogy Mapper can only observe lunar soil to a depth of a few
And the amount of water present in that layer is very
small. Jim Green is director of NASA's
Planetary Science Division. He points
out that even the driest deserts on Earth have more water than the surface of
the moon near its poles.
Still, the discovery raises some
important questions. Was water brought
to the moon by space rocks and icy bodies called comets? Or could processes deep within the moon
produce water? If that is the case, it
may be possible that the moon could hold enough water for future explorations
or even colonies.
space officials lost contact with Chandrayaan-One late in August. But another NASA project, the Lunar Crater
Observing and Sensing Satellite, or LCROSS, could provide answers to what lies
deeper beneath the moon's surface.
project involves crashing a rocket stage into the moon's south pole. LCROSS will then study the soil thrown up to
ten kilometers above the lunar surface before it too crashes into the moon. NASA scientists hope to extend their search
for water as deep as five meters beneath the surface of the moon. LCROSS is expected to crash into the moon next
Scientists have wondered for a long time
about where the substances necessary for life came from. Water exists on Earth and the planet Mars.
But what about important carbon-based molecules? Astronomers have recently found some
surprising evidence that some of those materials may have come from comets.
at the Goddard Space Flight Center in Greenbelt, Maryland, found the substance glycine
in material brought back to Earth from a comet.
Glycine is one of the common amino acids. On Earth, organisms use glycine to create
proteins. The discovery is exciting
because it suggests that the building blocks of life may be more common in the
universe than scientists had thought.
story of how space scientists were able to recover the material and bring it back
to Earth is just as exciting. NASA
captured the material using the Stardust spacecraft launched in nineteen
ninety-nine from Cape Canaveral, Florida.
Stardust passed through a cloud of material surrounding comet Wild Two in January of two thousand four.
A comet is a huge ball of
frozen gas and dust that often releases a long trail of material as it nears
the sun. A specially designed collector
gathered dust particles from the comet and stored them on the spacecraft. Stardust then returned to Earth and released
a special reentry capsule containing the material it had collected.
The recovery of the Stardust capsule
was difficult because of its high reentry speed. The capsule was traveling at almost forty-six
thousand kilometers an hour. It set a
record as the fastest human-made object to ever enter the atmosphere.
The Stardust capsule successfully parachuted onto a dry
plain in the state of Utah on January fifteenth, two thousand six. Since then, scientists around the world have
been working to identify substances gathered from Comet Wild-Two.
The discovery of glycine was not completely
unexpected. But it is the first time an
amino acid has been discovered on a comet.
Amino acids have already been found in space rocks called meteorites. There is also early evidence suggesting that
amino acids may also exist in the space between stars.
it took some time for the team to confirm that the amino acid glycine came from
space. Glycine is very common on Earth. And the team at Goddard Space Flight Center
was testing extremely small amounts of material. The researchers found the presence of carbon
thirteen, a version of the carbon atom that is usually found in space. The presence of carbon thirteen confirmed
that the glycine was from space.
Elsila led the research team. She said
the discovery "supports the theory that some of life's ingredients formed in
space and were delivered to Earth long ago by meteorite and comet impacts." The team's findings are to be published in
the journal Meteorics and Planetary Science.
The Hubble Space Telescope has again captured the
imagination of the public by returning extraordinary images of the solar system
and beyond. The telescope recently
received new equipment and instruments to make it even more powerful. NASA released some new pictures earlier this
month. One shows the remains of a dying
star four thousand light years away which has thrown off a cloud of glowing
of the Butterfly nebula shows the intense color and detail that only Hubble can
provide with such clearness.
Hubble Space Telescope was launched into orbit in April of nineteen ninety. The project cost one and a half billion
dollars. But when the telescope reached orbit,
NASA scientists were shocked to discover that the costly mirror of the
telescope had not been shaped correctly.
Hubble was still able to carry out observations. But it was not until nineteen ninety-three
that the problem was completely solved using corrective mirrors.
Hubble orbits about six hundred kilometers above the Earth's
surface. We think of the telescope as
moving slowly in its orbit. But it is
really traveling at twenty-eight thousand kilometers an hour. It completes an orbit of the Earth in only
The first image taken by Hubble
hardly showed its extraordinary power. It
was of a small area of a group of stars. Although it was not a colorful
picture, scientists were pleased. They
could compare it with images taken by Earth-based telescopes.
have now been five missions to service and repair Hubble. The repairs carried out in May by the crew of
the Space Shuttle Atlantis are expected to be the last. Astronauts added a new wide field camera and
a new spectrograph. They repaired an
existing infrared wavelength camera and spectrometer. And they fixed Hubble's directional controls
and batteries. The work required five
separate spacewalks over eleven days.
But the mission will keep Hubble alive until at least two thousand
This program was written and produced by Mario Ritter. I'm Steve
And I'm Shirley Griffith. You can see pictures from the Hubble Space
Telescope and find transcripts, MP3s and podcasts of our programs at
voaspecialenglish.com. Join us again next week for EXPLORATIONS in VOA Special