The news comes just a few days after a prominent chemist aired his theory that only on Mars were the right chemical elements – specifically boron, molybdenum and oxygen – present at the right time to produce RNA molecules. RNA is widely thought to be the precursor to DNA and therefore to life as we know it.
Both studies have brought renewed attention to the idea that life on Earth was seeded from space, a theory known as panspermia. However, they can't both be right. One idea requires Mars to be covered in liquid water, while the other needs it to be as dry as a desert.