Earth's airglow is seen with an oblique view of the Mediterranean Sea area. - Photo by Reuters

London: Scientists claim to have discovered a potentially habitable planet which has an environment much similar to that of Earth and may contain water and even life.

Exoplanet, called Gliese 581g, is located around 123 trillion miles away from Earth and orbits a star at a distance that places it squarely in the habitable or Goldilocks zone, scientists said.

The research, published in a paper published in Astrophysical Journal, suggests that the planet could contain liquid water on its surface, meaning it tops league of planets and moons rated as being most like Earth, they said.

“Our findings offer a very compelling case for a potentially habitable planet,” Vogt, lead researcher a professor of astronomy and astrophysics at the University of California Santa Cruz said.

The new findings are based on 11 years of observations of nearby red dwarf star Gliese 581 using HIRES spectrometer on Keck I Telescope by a team from UC Santa Cruz & Carnegie Institution of Washington.

The team reported discovery of two new planets around Gliese 581.

This brings total number of known planets around this star to six, the most yet discovered in a planetary system outside of our own.

“Like our solar system, planets around Gliese 581 have nearly-circular orbits,” team said.

It found that Gliese 581g has a mass three to four time the Earth's and orbits its star in just under 37 days.

Its mass indicates that it is probably a rocky planet with a definite surface and enough gravity to hold on to an atmosphere, they said.

Gliese 581 has two previously detected planets that lie at edges of habitable zone where atmosphere is just right temperature for liquid water to exist – one on hot side, other on cold face, scientists said.

While some astronomers still think “planet d” may be habitable if it has a thick atmosphere, others are sceptical.

The newly-discovered planet g, however, lies right in middle of habitable zone, they said. The planet is tidally locked to the star, meaning that one side is always facing the star and basking in perpetual daylight, while side facing away from star is in perpetual darkness. One effect of this is to stabilize planet's surface climates, according to Vogt