Nicole Karlis of Salon –
Could life as we know it have begun on Mars instead of Earth? A handful of scientists believe so, and even more think we should at least consider the possibility.
This special case of the overall theory of panspermia, where life on Earth began somewhere else and traveled or was planted here, has some prominent supporters. In a new Salon article, these proponents say the theory makes intuitive sense based on what the two planets are like.
Let’s review the facts. First, no one knows for certain where and how life began. We can backform theories based on what we know now, and what life is like throughout the fossil and carbon record on Earth.
Though the idea that life started on Mars before migrating on Earth sounds like some far-fetched sci-fi premise, many renowned scientists take the theory seriously. The general idea of life starting elsewhere in space before migrating here has a name, too: Panspermia. It’s the hypothesis that life exists elsewhere in the universe, and is distributed by asteroids and other space debris.