Messenger comets might be why Earth has life, asteroid Ryugu samples suggest

[Admin]

Samples of the asteroid Ryugu, returned to Earth by the Hayabusa2 mission, carry evidence that organic molecules important to life were once delivered to Earth by comets.

Messenger comets might be why Earth has life, asteroid Ryugu samples suggest : Read more

 

[rod]

Interesting report by space.com and the paper cited, https://www.science.org/doi/10.1126/sciadv.adi7203

Very detailed study but I did not find one reference in the paper to *life* or Earth getting life kick started for example via abiogenesis because asteroids, comets, or meteorites brought the stuff of life here. 15 references to earth and the paper made it clear this asteroid has been in a short orbital period now in its present location in the solar system.

"Ryugu should have experienced some degree of regolith resurfacing (33). Okazaki et al. (34) estimated cosmic ray exposure age of Ryugu samples to be ~5 Ma. As the average resurfacing time of the top ~1-m layer of Ryugu has been estimated to be longer at the near-Earth region (~2 to 8 Ma) than at the asteroid belt (<1 Ma), the relatively long sample exposure age suggests residence at the near-Earth region (1 au from the sun) for several Ma (14, 33, 34). This further suggests that the microcrater and the melt splashes reported here probably formed during Ryugu’s residence in a near-Earth orbit within the last ~5 Ma."

Whatever interpretation of organics said to be found, Ryugu has not existed for billions of years in its present position around the Sun.

 

[Manix]

So in a nutshell, without quite saying it, this is mounting evidence for the Panspermia hypothesis

 

[Torbjorn Larsson]

So in a nutshell, without quite saying it, this is mounting evidence for the Panspermia hypothesis

More likely it is evidence against it since it provides data on how organic material got to Earth where evolution could start. Panspermia is a hypothesis that life evolved elsewhere so is inherently less likely.

Life evolves and diversify fast, and we have now a trait phylogeny that show biology splitting from geology, so it is an easy process all the way. Thus we can take a recent analysis as suggesting life evolved on Earth (or most habitable planets) by more than 5 sigma compared against panspermia.

“We conclude that the maximum probability that panspermia sparked life on Earth is on the order of magnitude of 10-5, or 0.001%.

https://www.universetoday.com/16509...rth-in-the-past-could-they-have-brought-life/