CNUFOS.COM
11-08-2007
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Nov 8, 2007 9:31 AM |
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New Planet Discovery Thrills Astronomers |

WASHINGTON (Nov. 6) - NASA scientists said they discovered a fifth
planet orbiting a star outside our own solar system and say the
discovery suggests there are many solar systems that are, just like
our own, packed with planets. The new planet is much bigger than
Earth, but is a similar distance away from its sun, a star known as
55 Cancri, the astronomers said on Tuesday.
<---Image byLynette Cook, NASA / Getty Images The giant planets that
orbit 55 Cancri, as depicted in this artist's concept, are
inhospitable to life. But astronomers say it's possible water could
exist on a moon of the newly discovered planet.
Four planets had already been seen around the star, but the
discovery marks the first time as many as five planets have been
found orbiting a solar system outside our own with its eight
planets, said Debra Fischer, an astronomer at San Francisco State
University.
Life could conceivably live on the surface of a moon that might be
orbiting the new planet, but such a moon would be far too small to
detect using current methods, the astronomers said.
"The star is very much like our own sun. It has about the same mass
and is about the same age as our sun," Fischer told reporters.
"It's a system that appears to be packed with planets."
It took the researchers 18 years of careful, painstaking study to
find the five planets, which they found by measuring tiny wobbles in
the star's orbit. The first planet discovered took 14 years to make
one orbit.
They said 55 Cancri is 41 light-years away in the constellation
Cancer, a light-year being the distance light travels in one year --
about 5.8 trillion miles.
The newly discovered planet has a mass about 45 times that of Earth
and may resemble Saturn, the astronomers said.
HARBORING LIFE?
It is the fourth planet out from the star and completes one orbit
every 260 days -- a similar orbit to that of Venus.
"It would be a little bit warmer than the Earth but not very much,"
said Jonathan Lunine, a planetary scientist at the University of
Arizona.
The planet is 72 million miles from its star -- closer than the
Earth's 93 million miles, but the star is a little cooler than our
own sun.
"If there were a moon around this new planet ... it would have a
rocky surface, so water on it in principle could puddle into lakes
and oceans," said Geoff Marcy, an astronomer at the University of
California, Berkeley.
But the moon would have to carry a lot of mass to hold the water, he
said. Water is, of course, key to life.
"This discovery of the first-ever quintuple planetary system has me
jumping out of my socks," Marcy added. "We now know that our sun and
its family of planets is not unusual."
Marcy and other astronomers strongly believe that many stars are
hosts to solar systems similar to our own. But small objects such as
planets are very hard to detect.
Technology that would allow scientists to detect planets as small as
Earth is decades away, the scientists agreed.
The researchers have been looking at 2,000 nearby stars using the
Lick Observatory near San Jose, California, and the W.M. Keck
Observatory in Mauna Kea, Hawaii.
The inner four planets of 55 Cancri are all closer to the star than
Earth is to the sun. The closest, about the mass of Uranus, zips
around the star in just under three days at a distance of 3.5
million miles
Source - NASA |
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