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- The best images ever taken of Saturn's mysterious moon
Titan reveals a complex surface that may be home to icy landforms and frigid
hydrocarbon seas. They would be the only known open oceans in the solar
system, other than on Earth.
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- Astronomers from the US Lawrence Livermore National Laboratory
and the University of California have captured the images using the world's
largest telescope, the Keck reflector on Hawaii.
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- Sharper than those obtained by the Hubble Space Telescope,
the Keck images show dark regions that may be seas of liquid hydrocarbons,
as well as bright regions that may be ice-and-rock continents or highlands.
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- Secrets of life
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- Titan is 5,120 kilometres (3,200 miles) in diameter,
larger than the planet Mercury and is the only body in the solar system
with a nitrogen-rich atmosphere like the Earth's. Being 900 million miles
from the Sun, Titan is much colder than Earth, with a surface temperature
of minus 180 degrees Celsius (-290 F).
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- Scientists believe that Titan could be one of the most
important objects for scientific scrutiny in the entire solar system as
it may contain some of the secrets of the beginning of life.
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- The new observations confirm that Titan is chemically
rich. It contains many of the molecules that were on the Earth before life
arose on our planet.
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- When the Voyager spacecraft passed by in 1980, it saw
only the orange-brown top of Titan's smoggy skies. Now using the Keck telescope
scientists can get a more detailed view.
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- First map
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- "With the tremendous power of the Keck Telescope
we are able to map surface features 150 miles in size on a moon that is
more than 800 million miles from Earth. I find this tremendously exciting
to think about," said Claire Max of the Lawrence Livermore Laboratory.
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- "These models give the first quantitative map of
Titan's surface. The bright region shaped somewhat like a rubber duck seems
to be made of a mixture of rock and ice," astrophysicist Seran Gibbard
added.
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- A kidney-shaped region near the left edge of that image
is made of an extremely dark material. Scientists have long suggested that
ethane smog could condense and rain onto Titan's surface as a black liquid.
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- The dark material could be a sea of liquid methane, ethane
or other hydrocarbons," Livermore's Bruce Macintosh said. "It's
one of the darkest things in the solar system. It could also be solid organic
material."
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- Either possibility is exciting to scientists. If it is
a sea, it represents the only such open body of liquid known beyond planet
Earth.
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- A walk on Titan
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- Using this information it is possible to imagine standing
on Titan's frozen surface.
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- The ground beneath your feet would have the reddish colour
that dominates everything around you. As you look towards the horizon you
would see undulating hills of ice with dark red and yellow peaks and rivulets
of ochre on their flanks.
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- Looking down you could see how the Ethane sea has eroded
the base of one hill and you could see the scars made by recent icefalls.
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- It may even rain on Titan, but not rain as we know it.
Methane rain would fall more slowly and in bigger drops than on Earth.
They may lead to streams, rivers and oceans with rolling waves larger and
slower than on our own planet.
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- The Cassini spacecraft is currently en route to Saturn.
When it reaches it in 2004 it will drop a probe into Titan's atmosphere
that, with luck, will land on its surface and send back pictures.
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