Space - Tullamore Astronomical Society

NEWS UPDATE
From Around The Universe
New crater formation theory • HST searches for oxygen on the Moon •
Russia to launch Brazils first astronaut • 10 th ‘planet’ has a moon • Mars
was once like Earth • 2 new moons for Pluto • Life’s building blocks
abundant in space
Hubble Searches for Oxygen on the Moon
During the summer, scientists pointed the Hubble
Space Telescope at the Moon to take a closer look at
its soil. Initial findings support the potential existence of
some unique varieties of oxygen–rich glassy soils in
both the Aristarchus and Apollo 17 regions. They could
be well suited for visits by robots and human explorers
to learn how to live off the land on the Moon.
While Hubble wasn't specifically designed to
look at the Moon (it only has the resolution of a football
field for an object so close) scientists can use the
ultraviolet capability of its Advanced Camera for
Surveys to analyse the contents of lunar soil, particularly
minerals and ore that might contain oxygen.
Since the Moon does not have a breathable
atmosphere, and spacecrafts have limited load capacities,
harvesting oxygen from the soil may be critical for longterm
human missions. Hubble found that the soil in the
regions examined contained abundant amounts of
ilmenite, a mixture of titanium, iron, and oxygen.
Laboratory experiments on Earth have shown
that applying certain chemical processes to terrestrial
ilmenite can easily liberate oxygen and water. Water can
then be turned into oxygen and hydrogen, which could
also be used for rocket fuel.
Other studies have found evidence for water ice
near the lunar poles. While those areas might serve well
for human outposts, they are not necessarily the first
choices for science missions.
The Hubble team examined three lunar sites,
two of which – the Apollo 15 and 17 landing sites –
where soil chemistry is well known. The third was the
Aristarchus crater, a "geologic wonderland" that has
piqued geologists' interest for decades. The Aristarchus
crater is the brightest feature of the Moon's near side,
nearly twice as bright as most spots on the Moon and
visible to the naked eye. It's just 25 miles across but
more than two miles deep. At only 450 million years old,
it is one of the younger major features on the Moon.
More importantly, it sits in a region of the Moon
that scientists believe was once rocked by volcanic
explosions and tectonic shifts. The two-mile gouge
exposes the historical record of what went on in the
region, including the history of crust and mantle
formation on a young satellite.
Aristarchus crater was the planned landing site for
Apollo 18, but no human or robot has ever set foot there,
making it a likely target for the Lunar Reconnaissance
Orbiter as it explores the lunar surface in 2008,
according to current plans. Data from that mission,
combined with Hubble's observations, will help plan the
location of future robotic and human missions.
Craters in Planets and Moons Not What They Seemed
A hole in a moon or planet does
not always mean what
astronomers thought. Most of the
craters on Jupiter's moon Europa
are formed by chunks of rock and
ice splashing back down onto the
moon's surface after a meteor
strike, a new study suggests. It was
previously thought that most of the
craters seen on moons and planets
were the work of direct, or
"primary" impacts from asteroids
and comets. The new finding
suggests that most of those craters
might instead be "secondaries,"
impacts that formed by the
material ejected from primary
impacts.
For Europa, secondaries
account for as much as 95% of all
the small craters - those less than a
mile in diameter - observed on the
moon. The finding has
implications for how astronomers
date the ages of planetary surfaces.
Asteroids, comets and
chunks of cosmic debris routinely
bombard the surface of planets and
moons. Earth's atmosphere protects
us from most of these impacts,
incinerating most objects before
they hit the ground. Even so, Earth
has experienced countless meteor
impacts throughout its long
history. The evidence for most of
those impacts have been erased by
erosion from wind and rain and by
constant turnover of the Earth's
Réalta – Volume 7, Issue 2 – November/December 2005 – Tullamore Astronomical Society 5