Don't get your hopes up yet for galactic colonization, but a new planet has just been added to the Habitable Exoplanets Catalog. Gliese 832 c of the Gliese 832 star system is theorized to have temperatures close to Earth's, making it possibly habitable except for one glaring flaw: it has large seasonal shifts.
To some extent it is to be expected. Gliese 832 c has a mass at least 5 times that of the Earth. It receives the same amount of energy from its red dwarf sun as does Earth. All things considering, it is expected to have extreme seasons like this. In fact, while the theory is that it could be habitable, a denser planet such as this might also be too hot, making it more of a super-Venus rather than a super-Earth. In addition, there is still other unknowns that could tip the scales in either way, particularly the actual composition of the atmosphere.
Gliese 832 c is part of a star system that almost resembles our own Sol, just on a different size scale. The earth-like Gliese 832 c sits in the inner sanctum, closer to its star. But it wasn't the first to be discovered in that system. Gliese 832 b was actually discovered in 2009 and resembles our Jupiter, both in size relation to the super-Earth but also in distance, being further away from the red dwarf. Astronomers theorize that Gliese 832 b had the same role that our own Jupiter played in the formation of our solar system, particularly in the composition of the asteroid belt and Mars' stunted growth.
Despite these factors, Gliese 832 c is still one of the closest candidate to sustaining Earth-like life It has an Earth Similarity Index (ESI) of 0.81. The other top two contenders are Gliese 667C c with 0.84 and Kepler-62 e with 0.83. Gliese 832 c is also only 16 light years away.. In addition, given the similarities between our Sol and the red dwarf Gliese 832, scientists are curious if there are other Sol-like planets and materials in that system, though they aren't holding their breath as it is quite a rare case in space.
SOURCE: Planetary Habitability Laboratory of the University of Puerto Rico at Arecibo