CHILE: Earth-like planet discovered just outside solar system
- 00:00:28
- ITN Source
CHILE: Earth-like planet discovered just outside solar system
European astronomers have spotted what they say is the most Earth-like planet yet outside our solar system, with balmy temperatures that could support water and, potentially, life. They have not directly seen the planet, orbiting a red dwarf star called Gliese 581. But measurements of the star suggest that a planet not much larger than the Earth is pulling on it, the researchers say in a letter to the editor of the journal Astronomy and Astrophysics. "We have discovered a very low mass planet. In fact, it is the lowest mass ever discovered. It's only five times the mass of the Earth," said Michel Mayor of the Geneva Observatory in Switzerland. Most of the 200 or so planets that have been spotted outside this solar system have been gas giants like Jupiter. But this one is small. It appears to have a mass five times that of Earth's. The research team includes scientists credited with the first widely accepted discovery of a planet outside our solar system, in 1995. Many teams are looking for planets circling other stars. They are especially looking for those similar to our own, planets that could support life. That means finding water. "It is the first time that a planet is discovered with a mass similar to that of Earth's. It is not the same kind of mass but very close and, once again, with a distance that permits us to think that there may be water in the form of liquid," Chilean astronomer Claudio Melo said. Gliese 581 is among the 100 closest stars to Earth, just 20.5 light-years away in the constellation Libra. It is smaller and dimmer than the sun, so the planet can be close to it and yet not be overheated. A light-year is the distance light travels in a year, about 6 trillion miles (10 trillion km). The same team has identified one larger planet orbiting Gliese 581 already and say they have strong evidence of a third planet with a mass about eight times that of the Earth. Future missions, perhaps in 20 to 30 years, may be able to block the light from the star and take a spectrographic image of the planets. The colour of the light coming from the planet can give hints of whether water, or perhaps large amounts of plant life, exist there.
ITN Source | April 25, 2007
