New Planetary System
New planet has a mass 45 times that of Earth
by Liz Olson
In 2007, scientists announced that they found five planets
circling a star 41 light-years away from Earth in the constellation Cancer.
It is the most extensive planetary system ever discovered and one that
resembles our solar system. The first planet was detected in 1996 orbiting
its star called 55 Cancri at a distance of 500 million miles.
Until
2007, there were four known planets orbiting 55 Cancri. A fifth planet was
detected early in 2007 with a mass 45 times that of Earth. It orbits its
star in 260 days at a distance of 70 million miles, which is roughly the
distance of Venus from the Sun. The new planet may also have rocky moons
orbiting it, but none have yet been spotted. It is unlikely that the moons
could harbor life even if they do exist.
Although the newest addition
to 55 Cancri’s solar system is located in the so-called habitable zone
warm enough for liquid water, it is thought to resemble Saturn or Neptune
with an environment uninhabitable for life.
Professor Debra Fischer
of San Francisco State University led the team that reported this new
planetary system. With the discovery, Prof. Fischer and her team have shown
that our solar system is not unique in our universe, and with time and more
data, it is possible for astronomers to find more planets that resemble
Earth. In the last decade alone, 250 planets have been discovered orbiting
around stars.
Scientists detect planets using a wobble technique that
monitors the star’s light for variations that could be induced by the
gravitational pull of orbiting planets. At first, scientists could only
identify Jupiter-size planets, but with technological improvements they can
now find planets only a few times the size of Earth.
There is an
interesting 450 million mile gap between the new planet and the outermost
planet. A similar gap exists in our solar system between Jupiter and Mars
due to the disruptive effects of Jovian gravity on planetary formation. So
far no other planets have been detected, but there is a chance that other
planets could exist in the new planetary system’s gap. We can be
certain astronomers will be closely monitoring the gap in the future.
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