Panspermia & evidence of extra-terrestrial life

While men go … “to and fro over this globe about their little affairs” (in the words of H.G. Wells) a major scientific discovery was announced (26 April 2022) relating to extra-terrestrial life that supports the theory of panspermia. The theory is that life on earth originated from microorganisms or chemical precursors of life present in outer space and able to initiate life on reaching a suitable environment.

Researchers from Hokkaido University, Japan (and NASA) have discovered that the last two nucleobases (purines and pyrimidines) of the five needed to code for life are present in space. It provides evidence that life on earth may have come from space. It might even, with a stretch of the imagination, make us the children of extra-terrestrials.

The panspermia hypothesis

The panspermia hypothesis suggests that life exists throughout the universe because bacteria and microorganisms are spread by asteroids, comets, space dust and possibly even interstellar spacecraft. We have transferred bacteria to Mars and the Moon from contaminated spacecraft. Scientists have shown that rock fragments have travelled to Earth as ejected material from meteor impacts on Mars.

The building blocks of life from space

No living organisms have been found but the discovery shows that life’s “building blocks” are present in space. On Earth, all life relies on the deoxyribonucleic acid (DNA) and ribonucleic acid (RNA) molecules which contain instructions to build and maintain living things.

Information in DNA and RNA is made up of five components (nucleobases) composed of the organic molecules, purines and pyrimidines. Scientists have been unsuccessfully analysing meteorites for purines and pyrimidines for several decades. However, new experimental techniques were used in this study.

The Murchison Meteorite from Victoria

One of the meteorites containing purines and pyrimidines was found in Australia. It exploded in the atmosphere over Murchison, Victoria, 160 kilometres north of Melbourne, in 1969 and fell over an area around 35 square kilometres.

Museums Victoria holds fragments of the Murchison Meteorite, which is a rare “carbonaceous chondrite” type. Unlike most meteorites, it contains a lot of organic molecules and water (8%). Previously over 70 amino acids had been identified from the meteorite, only 19 known from Earth. It also contains tiny pre-solar grains—nano-diamonds and silicon carbides—that formed before our sun came into existence.

Should we be worried about aliens?

The hypothesis of panspermia that life on earth has come from outer space is still not supported by evidence. Experiments with bacteria, lichens, and fungi show they cannot survive long periods of time in space.

This new evidence does not prove that life evolved in space but only that the raw materials may have come from space with the conditions on Earth bringing them to life.