Gliese 581c- the New Planet Discovered in April Could Mean Extraterrestrial Life

On 4/4/07 a team of astronomers lead by Stephane Udry found a new planet in the constellation Libra that could potentially support life. The newly discovered planet, named Gliese 5281c, is 220th extrasolar planet found since the early 1990s and has scientists very excited. An extrasolar planet is any planet beyond our Solar System.

Xavier Delfosse, one of the team members stated, "Because of its temperature and relative proximity, this planet will most probably be a very important target of the future space missions dedicated to the search for extraterrestrial life. On the treasure map of the universe, one would be tempted to mark this planet with an X."

Gliese 581c orbits around the red dwarf sun, Gliese 581, which is only one third of the mass of our sun. Red dwarf suns are much more common, smaller, and cooler than our sun, which is a yellow dwarf. This allows Gliese 581c to maintain a comfortable surface temperature of 32-104 degrees Fahrenheit despite being only 7 million miles from its sun. Earth in comparison is 92.9 million miles from our sun. Astronomers are also speculating the Gliese 581c is 1.5 times the diameter of Earth and over five times heavier. Gliese 581c's orbital period or year would be about thirteen earth days.

Stephane Udry and his team found this new planet using HARPS (High Accuracy Radial Velocity Planet Searcher) at the European Southern Observatory in Chile. Udry has been involved in discovering eight-four extrasolar planets. The HARPS uses the radial velocity technique or "wobble effect" to detect potential planets far out in the universe. This means the astronomers can see small variations in the parent star's orbit because of the gravitational effect of the planet's size and mass.

Since Gliese 581c is so much closer to its sun that Earth, the tidal effects could be more than four hundred times as strong as the tidal influence of the Moon on Earth. Scientists have speculated that this could cause one hemisphere to be locked into daylight and have very high temperatures, while the other hemisphere would be forever in the dark and be very cold. Potential life would more than likely live in the "twilight" zone between the two hemispheres where temperatures would be more moderate. The potential for life and its complexity would also depend on whether the planet is rocky or icy and watery.

The next step in finding out more about Gliese 581c is to observe it from Canada's MOST space telescope. Future space missions would most likely involve sending a long-range probe, since Gliese 581c is 20 light years away or 120 trillion miles.

Astronomers are also still looking for extraterrestrial life closer to home. Life could be possible on the planet Mars since life forms do exists in very inhospitable places on Earth such as deep in the polar ice caps and on the edges of volcanoes and lava flows. Jupiter's moon, Europa, has large planetary fluctuations that may cause enough internal heat to keep water liquid under the surface ice and support life.