Origin of Life on Earth: What Do DNA, RNA, and Chemical Reactions in Asteroids Have to Do With It?

In a new set of analyses, researchers recently discovered the last two of the five informational units of RNA and DNA that had yet to be found in samples from meteorites.

As specified in a EurekAlert! report, while it is improbable that DNA could be formed in a meteorite, the finding shows that these genetic portions are available for delivery, not to mention, could have added to the development of the "instructional molecules on early Earth."

The finding, by an international research team from NASA, provides more evidence that chemical reactions in asteroids can make some of the ingredients of life, which could have been sent to ancient Earth by the meteorite effects or probably, the dust's infall.

Essentially, all RNA and DNA, which comprises the instruction to construct and operate each living being on this planet, consists of five information components known as nucleobases.

Nucleobases

At present, researchers souring extraterrestrial specimens had only discovered three of the five. Nevertheless, a recent assessment by a team of researchers led by Yasuhiro Oba, an associate professor from Hokkaido University, Hokkaido, Japan, specified the last two nucleobases that have elevated scientists.

As indicated in the study published in the journal Nature Communications, nucleobases are part of the classes of organic molecules known as "purines and pyrimidines," which have a great range.

Nevertheless, it stays a mystery, the reason more types have not been found in meteorites so far. Oba explained, he wonders why the said organic molecules are remarkable in that they do not exhibit structural diversity in "carbonaceous meteorites" unlike other classes of organic compounds like hydrocarbons and amino acids.

Oba, the lead author of the study added, "since purines and pyrimidines can be synthesized in extraterrestrial settings, as has been revealed by their own research, one would expect to discover a wide diversity of the organic molecules in meteorites.

'Extraterrestrial Broth'

According to the co-author of the paper, Danny Glavin from NASA's Goddard Space Flight Center in Greenbelt Maryland, they now have evidence of when life occurred.

This newly found pair of nucleobases, thymine, and cytosine have been elusive in past analyses likely due to their more delicate structure, which may have degraded when researchers extracted samples in the past.

In the earlier investigations, scientists developed something of a meteorite tea, placing grains of meteorite in a hot bath to enable the molecules on the sample to extract into the solution, and then, examined the molecules' makeup of the so-called "extraterrestrial broth."

Glavin explained that they are studying such water extracts since they contain the good stuff, archaic organic molecules that could have been key building blocks for the origin of life on this planet.

Due to how delicate the two nucleobases are, the researchers were skeptical at first, to see them in the specimens.

But the two factors may have added to the new finding. First, they used cool water to extract compounds, rather than hot formic acid, which is very reactive, not to mention, could have destroyed such fragile molecules in previous specimens. Second, more sensitive analytics were used that could pick up on smaller quantities of these molecules.

Related information about life on asteroids is shown on Destiny's YouTube video below:

Check out more news and information on Asteroids in Science Times.