Astronomers have found a planet and a star that are more like Earth and Sun than any previously found pair. The approximately 3000 light-years distant star Kepler-160 and its orbiting planet KOI-456.04 are close enough that even liquid water could be on the surface of the planet.
The discovery was made by researchers from the Max Planck Institute for Solar System Research (MPS) in Germany, who were studying a star that was first observed with NASA's Kepler space telescope. Investigations from 2010 indicated that Kepler-160 could be surrounded by two exoplanets. Now the researchers believe that the star actually hosts three or even four exoplanets, including the earth-like KOI-456.04.
The representation of an earth-like exoplanet by an artist. NASA / JPL-Caltech / T. Pyle
Most of the exoplanets discovered to date are larger than Earth, about four times the size or about the size of Neptune, and they usually orbit relatively close to their stars. But occasionally, astronomers discover a potentially rocky planet the size of the Earth. However, these are often orbiting red dwarf stars that emit only weak radiation and make the planet uninhabitable.
What makes KOI-456.04 so special is not only the fact that it is comparable in size to Earth, less than twice the size of Earth, but also that its star is similar to our Sun and at almost the same distance from Earth encircled. This means that it may be the right temperature to have liquid water on its surface.
Even if KOI-456.04 should absorb liquid water, do not plan to move there yet. Other factors affect habitability, e.g. B. whether the planet has an atmosphere that can have a profound influence on its surface temperatures. However, the potential for the planet is still impressive.
"The surface conditions on KOI-456.04 could be similar to those on Earth, provided the atmosphere is not too massive and not Earth-like," wrote the MPS in a statement. “The amount of light received by its host star is approximately 93% of the amount of sunlight received on Earth. If KOI-456.04 has a mostly inert atmosphere with a mild earth-like greenhouse effect, its surface temperature would average +5 degrees Celsius, which is about ten degrees below the mean global temperature of the earth. "