Bennu asteroid samples yield watery historical past, key molecules for all times – Melissas Meals Freedom

Till scientists had been capable of conduct a managed pattern return with a spacecraft and punctiliously curate and retailer the samples in nitrogen, we had by no means seen this set of minerals in a meteorite.

An sudden discovery

Earlier than returning the samples, the OSIRIS-REx spacecraft spent over two years making observations round Bennu. From that two years of labor, researchers realized that the floor of the asteroid is roofed in rocky boulders.

We might see that the asteroid is wealthy in carbon and water-bearing clays, and we noticed veins of white carbonate a couple of ft lengthy deposited by historical liquid water. However what we couldn’t see from these observations had been the rarer minerals.

We used an array of methods to undergo the returned pattern one tiny grain at a time. These included CT scanning, electron microscopy, and X-ray diffraction, every of which allowed us to have a look at the rock at a scale not attainable on the asteroid.

Cooking up the components for all times

From the salts we recognized, we might infer the composition of the briny water from which they fashioned and see the way it modified over time, changing into extra sodium-rich.

This briny water would have been a perfect place for brand spanking new chemical reactions to happen and for natural molecules to kind.

Whereas our staff characterised salts, our natural chemist colleagues had been busy figuring out the carbon-based molecules current in Bennu. They discovered unexpectedly excessive ranges of ammoniaan important constructing block of the amino acids that kind proteins in dwelling matter. Additionally they discovered all 5 of the nucleobases that make up a part of DNA and RNA.

Based mostly on these outcomes, we’d enterprise to guess that these briny pods of fluid would have been the right environments for more and more difficult natural molecules to kind, such because the varieties that make up life on Earth.

When asteroids like Bennu hit the younger Earth, they may have offered a whole package deal of complicated molecules and the components important to life, comparable to water, phosphate, and ammonia. Collectively, these parts might have seeded Earth’s initially barren panorama to supply a liveable world.

With out this early bombardment, maybe when the items of the Revelstoke meteorite landed a number of billion years later, these fragments from outer area wouldn’t have arrived right into a panorama punctuated with glaciers and bushes.

Timothy J McCoy is a supervisory analysis geologist on the Smithsonian Establishment, and Sara Russell is a professor of planetary sciences on the Pure Historical past Museum.

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