SATURN’S MOON TITAN A FROZEN WORLD
SATURN’S MOON TITAN A FROZEN WORLD
2005-02-26 at 10:30:00 am #10543Saturn’s Moon Titan a Frozen
WASHINGTON – Data from the
Cassini-Huygens spacecraft suggest that Titan, a moon of Saturn, is a world with
the potential of life that was frozen in its youth, prevented by deep cold from
ever developing into a livelier place.
“Titan is the Peter Pan of our solar system. It’s a
little world that never grew up,” said Tobias Owen of the University of Hawaii,
a member of an international team monitoring the findings of the Huygens
spacecraft sitting on Titan’s surface.
The minus 290 degree F temperature of Titan prevented
the chemical reactions that are thought to have occurred on Earth, possibly
leading to the evolution of life, said Owen, one of a group of researchers
presenting papers on Titan at the national meeting of the American Association
for the Advancement of Science.
“All of the elements that we are made of are there,”
Owen said Friday, “but all of the water is frozen solid. There’s no oxygen
available. If it could warm up, it would be beautiful.”
Ice appears to form the bedrock of Titan, he said, and
there is some suggestion of cryovolcanoes, volcanic-like vents that spew forth
ice instead of lava. Owen said features detected by the Cassini spacecraft,
orbiting Titan, show channels resembling volcanic features on Earth, but they
may have been carved by creeping ice, not molten rock.
Owen said the evidence for ice volcanoes on Titan is
“shaky,” but it is the leading theory to explain some of the features seen on
the body.“We’re not expecting to find life on Titan. It’s just
too cold,” said Owen. “But we expect to find the primordial ice cream” – the
complex of chemicals that could possibly be the precursors to life.
Cassini-Huygens is a joint NASA-European Space Agency
project. The combined craft was launched in 1997 and arrived in orbit of Saturn
last year. Huygens, a lander developed and controlled by the ESA, touched down
earlier this year.Early studies show Titan is covered with pools of
methane, an organic chemical maintained on the surface by deep cold.
Owen said that Huygens apparently landed in a “mud”
formed by methane and that heat from the craft created a cloud of the gas that
instruments quickly analyzed and identified.
Titan’s intense cold and atmospheric pressure – about 1
1/2 times that of Earth – keep methane in a liquid state. Researchers earlier
said there are methane showers on Titan and a methane fog.
Methane is a highly flammable gas, but there is no free
oxygen on the moon to support combustion. Instead, methane flows and showers and
pools.“Methane takes the role that water does on Earth,”
said Owen. “And ice is like sand.” He said in Titan’s intense cold, chips of
ground ice could be like beach sand, drifting with the flow of methane.
Dennis Matson of NASA’s Jet Propulsion Laboratory said
that ice forms the bedrock of Titan and that sometime during the formation of
the moon the frozen water may have warmed enough to flow to the surface like
lava in a volcano on Earth.“It would be the consistency of magma. At some
temperatures below freezing, ice is pliable,” he said. “It could flow like
toothpaste out of a tube.”Matson emphasized that the ice volcano concept is still
a theory, but it offers the best explanation for some features seen on the
surface of Titan.Scientists at the conference also reported on the
progress of Spirit and Opportunity, two rolling robots that have been exploring
the surface of Mars for more than a year.
Steven W. Squyres of Cornell University, one of the
principal scientists on the Martian rover mission, said Spirit took a
self-portrait with one of its cameras that shows the craft’s solar power panels
coated with a reddish grime. This cuts down on the amount of sunlight the craft
can use to make electrical power.“It is so dirty that it is important that we always
orient it toward the sun,” said Squyres. “We are slaves to the sun.”
A self-portrait by Opportunity shows that its solar
panels are clean, “like it’s just off the showroom floor,” Squyres said.
Spirit, which is slowly exploring the north flank of a
Martian hill named Husband, has found bedrock sticking out of the red soil. It
also churned up surface soil, and pictures sent to Earth show a layer of
“bright stuff” that Squyres said is probably a type of sulfur salt.
The rover also photographed layers of fragile-appearing light
rock that researchers believe is basaltic sand glued together with a
magnesium-sulphur salt. Such a process could occur in a pool of water, said
Squyres. Earlier studies have shown that liquid water once flowed in great
quantities on Mars, but the planet’s surface is now very dry.
_____________________________________Astronomers Spy Monster Explosion in
WASHINGTON – A cosmic explosion just across the Milky
Way from Earth gave off as much energy in one-tenth of a second as the sun does
in 100,000 years, astronomers reported on Friday.
The blast observed on Dec. 27 came from a neutron star
– a collapsed dead star with a sun-like mass squeezed into a sphere just 15
miles across — in the constellation Sagittarius (the Archer).
Even at a distance of 50,000
light-years, the explosion was powerful enough to bounce off the moon and
disturb Earth’s upper atmosphere, researchers said at a briefing at NASA
headquarters. A light-year is about 6 trillion miles, the distance light travels
in a year.
It interfered with many
satellites and overloaded receptors on some spacecraft, but was blocked by the
atmosphere and had little practical effect on Earth except to disrupt some very
low-frequency radio transmissions, the scientists said.
“Astronomically speaking, this
burst happened in our backyard. If it were in our living room, we’d be in big
trouble,” said Bryan Gaensler of the Harvard-Smithsonian Center for
Astrophysics.Neutron stars are rare enough,
but this one was an exotic type known as a magnetar, with an ultra-strong
magnetic field capable of stripping information from a credit card at a distance
halfway to the moon.If such a blast occurred within
10 light-years of Earth, it could destroy much of the ozone layer and cause mass
extinction. Fortunately, the nearest known magnetar is about 13,000 light-years
away, astronomers said.It would have been impossible to
see the explosion with the naked eye. It also was impossible for optical
telescopes to spot because the blast was brightest in the gamma-ray range, not
in the optical light range.Instruments that measure gamma
rays, X-rays and radio waves detected it as a huge spike in energy.
It is only the third time
astronomers have detected this kind of blast in our galaxy, and this one is 100
times stronger than the previous