Well, to be fair, we’re talking about meteorites today and not asteroids.
DEAL WITH IT.
Anyway, the idea that there is other life out there in the universe is a pretty tantalizing notion, one that teases us all, from conspiracy theorists to astrophysicists. With all of the galaxies with all of their star systems out there, it seems strange to not believe there could be some other form of “life” out there, going about its business.
But life on our own planet appears to have been a happy accident, a fortuitous combination of time and temperature and the infusion of the material building blocks of what would eventually become our world, teeming with life. The favored theory is that a meteorite carrying the requisite minerals and such that could provide the final link in the chain that is our origin plopped down in the ancient sea and BAM! Life happened (albeit not immediately… loses a bit of its gravitas when you explain that, though, doesn’t it?).
And recently, studies have shown that the creation of some of those required bits and bobs, amino acids (the building blocks of proteins which speed up chemical reactions and build essential structures like hair, skin, and nails), can occur in multiple ways.
Backing up for a second, a team at NASA’s Goddard Space Flight Center in Greenbelt, MD has been studying carbon-rich meteorites for a while now. They’ve already found amino acids in some that were created by a low-temperature process called Strecker-cyanohydrin synthesis. Which makes sense.
See, high temperatures tend to destroy amino acids.
But nature finds a way, and the researchers were surprised to find a type of amino acid present that was formed in much higher temperature (200- 1000°F) reactions called Fischer-Tropsch-type (FTT) reactions.
What’s particularly interesting about FTT reactions is that, unlike the Strecker reactions, liquid water is not required for amino acid creation. In fact, FTT reactions could have been creating amino acids on these meteorites long before water formed on them or other planets by snagging the needed components (hydrogen, carbon monoxide, and nitrogen, all common space gasses) right out of the air, so to speak.
While the FTT reactions produce fewer amino acids than the Strecker reactions, the idea that both are possible out there in spaceland is delicious to me, because it opens the door of plausible alien life a little wider. Having multiple ways that an essential building block of life can form makes it statistically more likely that more life does exist out there.
And don’t worry- these samples appear quite pristine, with the researchers citing the components and shape of the amino acid chains to be inconsistent with most amino acids that form naturally, as well as their careful study of the surrounding regions, which yielded extremely low amino acid counts, proving there was little terrestrial contamination. With these mostly pristine samples, we can safely believe that the majority of the amino acids found on the meteorites were formed in space.
The group plans to expand their research to include all groups of carbon-rich meteorites. While finding amino acids on these meteorites was considered a long-shot before, the scientists would now be more surprised to not find them.
I love this study. It’s not showy or anything, but it does build our ideas of how life could form both here and on other worlds, and it’s a tidy little example of how scientific discoveries can change how we view things, even if those things are simply amino acids on space rocks.