Researchers have discovered the closest rocky planet outside Earth's solar system orbiting a nearby star, according to research published in the journal Nature on Wednesday.
The planet known as Proxima b is located just four light-years away from Earth around the red dwarf star Proxima Centauri, the closest star to the Sun, a team of scientists led by British researchers write in the magazine.
The scientists discovered the planet with data from the European Southern Observatory telescope in Chile by monitoring shifts in the light from the star to determine presence of the planet.
Proxima b has a mass 1.3 times that of Earth, but orbits much closer to its star, circling it every 11 days. Because the star itself is weaker than the Sun, Proxima b could be within the so-called habitable zone, where it is neither too hot nor too cold to support life and where temperatures could allow the presence of liquid water, the researchers said.
Researchers however have no idea whether the planet has an atmosphere or contains water, but "the existence is plausible," said Angsgar Reiners, a German scientist who is among the research's co-authors.
Scientists have discovered more than 3,500 so-called exoplanets outside the solar system, but Proxima b bring one within possible reach of a future space mission.