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Kepler-186f is one of the most Earth-like planets that NASA's space-venturing telescope has ever identified. First uncovered last April, it sits roughly 500 light years from Earth and is thought to be a rocky planet slightly larger than our own. Here, the artist is playing with the idea that photosynthesis on the surface could be affected by a nearby red dwarf star.

As the poster's design implies, HD 40307g (see, not very memorable) has a strong gravitational pull that far outstrips the one found on Earth. Uncovered by a team of astronomers using the HARPS spectograph at the European Southern Observatory, it's considered a super-Earth and sits 55.8 million miles from its parent star.

Two suns, you say? That's right, just like Luke Skywalker's home world of Tatooine, Kepler-16b orbits a pair of giant stars. NASA suspects the planet is a gas giant, so were you to make the trip we wouldn't recommend walking outside and taking in a huge gulp of fresh air.