Extremophiles, Comets, and Alien Organisms: How did life on Earth Begin?

As we are all well aware, this is a fiercely debated topic. While there is convincing evidence which indicates that other planets could possibly harbor life, we still lack concrete evidence proving that there is even the simplest form of life existing on an alien planet.

However, we don’t have to look very far to find evidence which suggests that life could survive on climates that are far more hostile than what is generally found on Earth. Ultimately, Earth contains a number of extremophiles -- organisms that have evolved to live in the harshest conditions -- conditions that we, as humans, would consider completely inhospitable. As scientists made advancements in this field of research, they discovered creatures that survive without the presence of oxygen living down in the deepest depths of oceanic volcanoes; they found organisms that can live in subzero temperatures or survive 185F (85C) heat, and life forms that thrive with absolutely no sunlight.

These findings contradict our previous assumptions about the minimal conditions required for sustaining life. But if you weren’t blown away by how life can live in those habitats, then perhaps this creature will impress you. These miniscule creatures are known as tardigrades, and they can exist in the vacuum of space. Although these creatures can only exist here in a kind of hibernation, it is believed that they could travel throughout the cosmos, eventually crash into another plant, unfreeze themselves, and once again become fully functioning life forms (this is known as “Panspermia”).

How does this impact our understanding of the start of life on Earth? Find out at:
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Image source before editing:
http://www.daviddarling.info/encyclopedia/P/panspermia.html