It is at a distance 20 light years from earth. The fourth planet, G, is a planet that could sustain life. Astronomers (scientists who study space) have discovered some planets that orbit Gliese 581. Although this is far in earth terms, it is relatively close in astronomical distances. Like our solar system, the planets around Gliese 581 have nearly-circular orbits. Gliese 581 (/ ˈ ɡ l iː z ə /) is a star of spectral type M3V (a red dwarf) at the center of the Gliese 581 planetary system, about 20 light years away from Earth in the Libra constellation.Its estimated mass is about a third of that of the Sun, and it is the 89th closest known star to the Sun. The closest habitable planet to Earth is Gliese 581 c. It was discovered in 2007. The planet was announced on November 30, 2005 and was discovered by … The Gliese 581 star has about 30% the mass of our sun, and the outermost planet is closer to its star than we are to the sun. Image Credit: National Science Foundation/Zina Deretsky
It is also known as HO Librae, GL 581, or GJ 581. The two planetary neighbours of Gliese 581 c are way bigger planets with Gliese 581 b exceeding the size of Neptune (i.e. The astronomers agree that four of the planets are real, but some think there are two more planets. This brings the total number of known planets around this star to six, the most yet discovered in a planetary system outside of our own.
fifteen to seventeen earth masses) in our own solar system and Gliese 581 d being of some eight earth masses.

Gliese 581b is an extrasolar planet orbiting the red dwarf star Gliese 581.It is the second planet in order of the three currently known, and was the first planet in the Gliese 581 system to be discovered. Gliese 581 is an M-class red dwarf star that is not far from the Earth.It is 22 light years away from the Solar system.This makes it the 89th closest known star to the Sun. The orbits of planets in the Gliese 581 system are compared to those of our own solar system. It is also known as HO Librae, GL 581, or GJ 581.. Astronomers have discovered some planets that orbit Gliese 581. The Gliese 581 planetary system now has four known planets, with masses of about 1.9 (planet e, left in the foreground), 16 (planet b, nearest to the star), 5 (planet c, centre), and 7 Earth-masses (planet d, with the bluish colour). Earth like Life on Gliese 581c Physical Science The planet Gliese 581c, located just 20 light-years from the solar system (in the constellation Libra) and for a time one of the smallest known extrasolar planets, has captured attention in recent years as one of the most likely candidates for life-bearing planets outside of our own solar system. The Gliese system has now become a focus for future investigation by mainstream space research astronomy. Gliese 581 is an M-class red dwarf star that is not far from the Earth.It is 22 light years away from the Solar system. The atmosphere should be thick enough to reflect the rays coming from the red dwarf and the surface temperature ranges between 32 to 104 F. The new planet designated Gliese 581g has a mass three to four times that of Earth and orbits its star in just under 37 days. This makes it the 89th closest known star to the Sun. Gliese 581 c or Gl 581 c is a "Super-Earth", a large extrasolar terrestrial planet, orbiting the red dwarf star Gliese 581. As Gliese 581c is 15 times closer to the red dwarf as compared to the distance between earth and sun.