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Did we just prove panspermia?

Analysis of samples from a couple of asteroids visited by robotic craft has just provided a substantial boost to the theory of panspermia.

What is panspermia?

It's the theory that life could be (or has been) spread across the universe by hitching a ride on chunks of space rocks, in the form of asteroids or even meteors.

Scientists examining samples from the asteroid Bennu have discovered some very interesting molecules that could well be the precursors to life.

This New Scientist article reports that "the presence of ribose, as well as other sugars, including lyxose, xylose, arabinose, glucose and galactose" has been detected in the samples that were returned to earth from Bennu by the OSIRIS-REx craft.

These relatively complex organic molecules are apparently a surprise and lend weight to the theory that life on Earth may have originated as the result of similar asteroids crashing into its surface several billions of years ago.

The article quotes Dr Sara Russell from the Natural History Museum in London as stating “The one missing ingredient was the sugar [ribose], which has now been reported, so now all of the ingredients of RNA are known to be in primitive asteroids.”

If panspermia turns out to be a real thing then it significantly increases the chances that we are not alone in the universe. Whether wandering asteroids are themselves the catalyst for the precursors to life or whether they have scooped up organic material as the result of glancing blows with other worlds is unsure but the potential for distributing life across celestial bodies is significant.

For many decades, scientists have been trying to solve the puzzle of how the self-replicating molecules that are the basis of life managed to form on the surface of a primitive Earth.

Many experiments which attempted to reproduce the chemical environment of our planet back in the pre-life era involved passing electrical currents to simulate lightning, through mixtures of ammonia and methane gases in the hope that more complex organic chains would be formed. One such attempt, conducted in the early 1950s, was the Miller-Urey experiment which did successfully create some basic amino acids but nothing rivalling the complexity of organic molecules recently discovered on Bennu.

Now we have two possible pathways to the appearance of life on Earth but much work remains to determine which, if either, was the likely winner.

I guess the bottom line, when it comes to the spontaneous appearance of life in an otherwise lifeless universe is that "given enough time, anything that can happen, will happen".

Carpe Diem folks!

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