When we think about what could go wrong when we make first contact with an alien race, the first thing that usually comes to mind is total planetary destruction.
Earth is pretty good at supporting life, but according to a new estimate of what constitues a planetary "habitable zone," it looks like our planet (and perhaps many others) is only barely in the right place.
A lot of people have claimed they can prove aliens are real over the years, but very often those people are just self-proclaimed experts with no real evidence.
A while back we told you about the discovery of a former star that had basically formed into a huge, planet-sized diamond. Now scientists think they've found another cosmic body with a thick diamond core, and it's only 40 light-years away.