Could the blueprint for life have been generated in asteroids?

Scientists have found the last two of the five informational units in meteorites, using new analyses. This discovery shows that the genetic parts are available for delivery and could have contributed to the development of the instructional molecule on early Earth. The discovery, by an international team with NASA researchers, gives more evidence that chemical reactions in asteroids can make some of life's ingredients, which could have been delivered to ancient Earth by meteorite impacts or perhaps the infall of dust.

The instructions to build and operate every living being on Earth are contained in all DNA andRNA. Scientists had only found three of the five samples. A recent analysis by a team of scientists identified the final two nucleobases that have eluded scientists.

Purines and pyrimidines are classes of organic molecules that have a wide variety. It is not known why more types haven't been discovered in meteorites.

"I wonder why purines and pyrimidines are exceptional in that they don't show structural diversity in carbonaceous meteorites unlike other classes of organic compounds such as amino acids and hydrocarbons."

Danny Glavin, a co-author of the paper, said that the complete set of nucleobases used in life today could have been available on Earth.

The more delicate structure of the newly discovered pair of nucleobases may have made them hard to find in previous analyses. In the earlier experiments, scientists created something of a meteorite tea and placed the grains in a hot bath to let the molecules on the sample extract into the solution.

The good stuff in the water extracts could have been key building blocks for the origin of life on Earth, according to Glavin.

The team was skeptical to see the two nucleobases in the samples. The team used cool water to extract the compounds instead of hot formic acid, which could have destroyed the fragile molecule in previous samples. Second, more sensitive analytic tools were used that could pick up smaller amounts of these molecules.

The group has managed a technique that is more like cold brew than hot tea and is able to pull out more delicate compounds.

The finding doesn't provide a smoking gun as to whether life on Earth got an assist from space or came about exclusively in the prebiotic soup in the planet's infancy. The completion of the set of nucleobases that make up life today, in addition to other compounds found in the sample, gives scientists who are trying to understand the beginning of life more compounds to experiment with in the lab.

Dworkin said that meteorites have been found to have sugars and bases.

This analysis adds to the kit for those modeling the beginning of life on Earth, as well as providing a proof of concept for a more effective technique to extract information from asteroids in the future, especially from the samples of Bennu making their way to Earth in the next year via NASA.

More information: Yasuhiro Oba, Identifying the wide diversity of extraterrestrial purine and pyrimidine nucleobases in carbonaceous meteorites, Nature Communications (2022). DOI: 10.1038/s41467-022-29612-x. www.nature.com/articles/s41467-022-29612-x Journal information: Nature Communications Citation: Could the blueprint for life have been generated in asteroids? (2022, April 26) retrieved 26 April 2022 from https://phys.org/news/2022-04-blueprint-life-asteroids.html This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.