Earth already contains organisms that survive conditions humans could never endure. Alien life, if it exists, may force ...

Alien life may not need the kind of home humans instinctively search for. Some of the strangest possibilities begin once ...

When scientists search for alien life, they usually look for planets that resemble Earth. The reasoning is simple. Every known living thing depends on liquid water, carbon based chemistry, and the ...

Claims that aliens are already here are everywhere, but proving them is another matter. The strongest cases become more ...