During their 2012 expedition to Antarctica, a team of Japanese and Belgian researchers stumbled upon a small rock, now known as meteorite Asuka 12236. It is now believed that this golf-sized object can help them solve a big mystery about early building blocks of life.
According to the press release, astrobiologists at NASA's Goddard Space Flight Center in Greenbelt, Maryland discovered that the primitive rock specimen is rich in amino acids, the building blocks of the human and animal body that is present in all body tissues and play an essential role in the functioning of physical and mental processes. Various types of amino acids make arrangements that form into proteins important for essential bodily functions. They found both left-handed and right-handed varieties. However, decoding meteorite's composition unveiled a great proportion of left-handed ones.
While Asuka 12236 remains one of the best-preserved rocks of its kind, it was found out that the amino acid concentration is twice as much as space rock called Paris. Paris is also a meteorite that was of the same class which was previously thought to be the best-preserved.
"The meteorites are telling us that there was an inherent bias toward left-handed amino acids before life even started," leading author of the study Daniel P. Glavin said. "The big mystery is why?"
"It is pretty unusual to have these large left-handed excesses in primitive meteorites," he added. "How they formed is a mystery. That's why it's good to look at a variety of meteorites, so we can build a timeline of how these organics evolve over time and the different alteration scenarios."
To find answers to their questions, the team of researchers has probed hundred of meteorites. Investigating the type and amount of amino acids found inside these rocks helped scientists develop insight into how these molecules have evolved over the centuries.
It is believed that Asuka is one of the oldest meteorites that "predates the solar system." This makes it the best preserved in a category of carbon-rich meteorites known as CM chondrites.
"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 joined the team in the investigation of Asuka 12236.
The study was published in the journal Meteoritics and Planetary Science.