... Also, the home star to CoRoT-7b , although 500 light years distant, is very similar to our Sun. Unfortunately, the similarities likely end there, as CoRoT-7b orbits its home star well inside the orbit of Mercury , making its year last only 20 hours, and making its peak temperature much hotter than humans might find comfortable. ... Future observations will likely narrow the composition of one of the first known rocky planets discovered outside of our Solar System. ... NASA Official: Jay Norris. ...