LIFE’S COSMIC ORIGIN
The most fundamental and philosophical mystery around has got to surround where life came from. It is one thing to discuss how life grew from a single-cell organism to this global presence of intelligent life, but to then ask how the first single-cell organism arrived in the first place further complicates things. Here we’ll explore one possibility, the introduction of the ingredients via asteroids and comets.
Let’s examine the timeline based on known facts about the Solar System and Earth. The Sun, the planets and all the comets and asteroids scattered across the Solar System came into existence roughly 4.5 billion years ago, 9.3 billion years after the formation of the universe. 4.2 billion years ago, water was able to condense on Earth in the Solar System’s habitable zone – the distance from the Sun where temperatures allow liquid water to exist. Then, 3.7 billion years ago, the oldest-known form of life was present on Earth in the form of cyanobacteria known as stromatolites.
