A team of US astronomers announced recently they have discovered a planet very similar to our Earth orbiting a red dwarf star “only” 42 light years away. What is most interesting about a discovery heralded as a ”major breakthrough in humanity’s search for life on other planets”, according to CNN, is that the planet is composed mainly of water, possibly in liquid form.

According to self-described space geek Ian O’Neill, writing for Discovery News, the planet could be a “super-Earth”, an exoplanet, or extra-solar planet, with a mass of five to 10 Earths. In this case, the planet, called GJ 1214b, is six-and-a-half times the mass and nearly three times wider than our planet.

A team at the Harvard-Smithsonian Center for Astrophysics in Cambridge, Mass., estimates that this super-Earth could be made of up to three quarters of water. However, GJ 1214b not likely to be habitable, having a surface temperature of around 530 degrees Fahrenheit (280 degrees Celsius). Atmospheric conditions prevent water from boiling, as it would happen on Earth, O’Neill reported.

“This planet is the most Earth-like planet yet discovered,” said Geoffrey Marcy of the University of California at Berkeley. Sara Seager of MIT told magazine Science News that this discovery marks the “eve of a new phase of exoplanets studies.” She added, ”This planet is a harbinger of what’s to come. It’s not just that we can study this one object in more detail. It’s the torch, telling us about this new thing that’s going to happen.”

The discovery, made with a network of amateur telescopes, is just the first step of an on-going project.  David Charbonneau, who led the observations, said: “In time, we expect to find planets that are further away from their parent stars and so are likely to have surface temperatures much closer to those found on Earth.”

The discovery was reported in the science journal Nature.