One common theory for how life on Earth began is through a concept known as panspermia. According to this theory, certain microorganisms could survive the lifeless space between planets. The microorganisms could have been flung from a far away planet after an asteroid hit said celestial body.
Fragments of rock from the destroyed planet and asteroid could then be ejected into deep space, and over the course of billions of years, these fragments dotted with microbes litter other planets, thus seeding life elsewhere in the universe.
This theory would suggest that life in the universe stemmed from a single “genesis” – the seemingly miraculous point where life emerges.
However, researchers have now stated life elsewhere in the solar system would not be the result of panspermia, but rather its own “second genesis”.
Purdue University geophysicist Jay Melosh ran simulations to show the chance of Enceladus – a moon of Saturn and somewhere scientists have touted as being a possible home for life – being hit by a meteorite or other space fragment which carried the same microbial life to Earth more than 4.5 billion years as just 0.0000002 percent to 0.0000004 percent.
Running the same simulation for Europa – one of Jupiter’s moons – the chances are slightly higher, but still extremely unlikely at 0.00004 percent to 0.00007 percent.
This would suggest that life emerging in the cosmos is not a miracle, but that the universe has the conditions to support life and it is in fact common throughout.
Mr Melosh said at the annual meeting of the American Geophysical Union: “So, the bottom line: If life should be found in the oceans of Europa or Enceladus, it is very likely that it’s indigenous rather than seeded from Earth, Mars or (especially) another solar system.”
NASA has plans to travel to Europa, which is one of 79 moons orbiting Jupiter, between 2023 and 2025 with its Europa Clipper spacecraft.