One of the Best-Preserved Meteorites Offers Key Insights on Life’s Building Blocks

One of the Best-Preserved Meteorites Offers Key Insights on Life’s Building Blocks

Meteorite Asuka 12236 was discovered in a 2012 expedition to Antarctica. It was at the time and remains one of the best-preserved meteorites of its kind ever discovered.


Today, NASA scientists believe it could help them uncover the mystery of how the building blocks of life came to flourish on Earth. And all it took was a teeny sliver of the meteorite.

Astrobiologists at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, first crushed a 50-milligram pinch of Asuka 12236 and suspended the amino acids from its dust in a water solution.

They then proceeded to run the liquid through an analytical machine that separated the molecules inside by mass, identifying each one. What did the researchers find inside this primitive rock?

A bunch of amino acids! But not any kind of amino acids. These were left-handed versions of the amino acids.

Aminos come in right-handed and left-handed mirror-image versions just like your hands are mirror images of each other. More interestingly, life forms use only left-handed amino acids to build proteins.

“The meteorites are telling us that there was an inherent bias toward left-handed amino acids before life even started,” said Goddard astrobiologist Daniel P. Glavin. “The big mystery is why?”

To answer that question Glavin and his team are studying all kinds of meteorites. Asuka 12236 is a particularly useful type of meteorite because it is so well-preserved.

This is because it was exposed to very little liquid water or heat, both during its time as an asteroid and later on when it landed in Antarctica.

“It's fun to think about how these things fall to Earth and happen to be full of all this different information about how the solar system formed, what it formed from, and how the elements built up in the galaxy,” said Conel M. O'D. Alexander, a scientist at the Carnegie Institution for Science in Washington, D.C., who helped on the Asuka 12236 analysis. What else may the NASA scientists discover?

Watch the video: Geochemistry 1: Building a Planet (May 2021).