Astronomers searching for new planets have found a planet that appears to be a twin to Venus. The planet – GJ 1132b —about 16 percent larger than Earth — is rocky, hot, a similar size to Venus and orbits a similar type of star to the Sun, although at a much closer distance. The planet is around 39 light-years from Earth. GJ 1132b was discovered by the MEarth-South array in Chile.
The time-lapse movie below shows MEarth-South discovering the planet GJ 1132b; one telescope identified a dip in brightness of the star GJ1132 and immediately confirmed it with high-cadence observations.
The distance allows astronomers to assess the planet’s atmosphere, thanks to a new generation of telescopes. At nearly 400 trillion kilometers away, it is unlikely any spacecraft would ever reach it. An example of such future telescopes is the James Webb Space Telescope, set to come into operation in 2018.
The reason the planet is exciting is because it could once have been Earth-like. Although the planet cannot support life, it means to some astronomers that the hunt for an Earth-like planet is closer. Zachory Berta-Thompson, of Massachusetts Institute of Technology and who led the team that found the planet, told BBC Science: “The exciting thing is that, yes, it is probably true that the closest potentially habitable planets are going to be orbiting such stars.”
To study the atmosphere of a planet, light from a star must be scanned as the planet passes in front of the star and at a configuration as viewed from Earth. In the case of GJ 1132b visualization is easier because the star is a red dwarf. A red dwarf is a small and relatively cool star. They have a constant luminosity and many are orbited by planets.
