Life’s building blocks discovered on surprising meteorite

WASHINGTON - Scientists have identified amino acids, a fundamental building block of life, in a meteorite where none were expected.

“This meteorite formed when two asteroids collided. The shock of the collision heated it to more than 2,000 degrees Fahrenheit, hot enough that all complex organic molecules like amino acids should have been destroyed, but we found them anyway,” said Daniel Glavin of NASA’s Goddard Space Flight Center.

“Finding them in this type of meteorite suggests that there is more than one way to make amino acids in space, which increases the chance for finding life elsewhere in the Universe,” he said.

Previously, scientists at the Goddard Astrobiology Analytical Laboratory have found amino acids in samples of Comet Wild 2 from NASA’s Stardust mission, and in various carbon-rich meteorites.

Finding amino acids in these objects supports the theory that the origin of life got a boost from space-some of life’s ingredients formed in space and were delivered to Earth long ago by meteorite impacts.

Because of an unusually violent collision in the past, this asteroid’s ingredients for life were a “culinary disaster” and now mostly in the form of graphite. The small asteroid, estimated at six to fifteen feet across, was the first to be detected in space prior to impact on Earth on October 7, 2008.

A meteorite sample was divided between the Goddard lab and a lab at the Scripps Institution of Oceanography at the University of California, San Diego.

The extremely sensitive equipment in both labs detected small amounts of 19 different amino acids in the sample, ranging from 0.5 to 149 parts per billion. The team had to be sure that the amino acids in the meteorite didn’t come from contamination by life on Earth, and they were able to do so because of the way amino acids are made.

The sample had various minerals that only form under high temperatures, indicating it was forged in a violent collision. It’s possible that the amino acids are simply leftovers from one of the original asteroids in the collision-an asteroid that had better conditions for amino acid formation.

However, the team thinks its unlikely amino acids could have survived the conditions that created the meteorite, which endured higher temperatures more than 2,000 degrees Fahrenheit (over 1,100 Celsius) over a much longer period.

Instead, the team believes there’s an alternate method for making amino acids in space.

“Previously, we thought the simplest way to make amino acids in an asteroid was at cooler temperatures in the presence of liquid water. This meteorite suggests there’s another way involving reactions in gases as a very hot asteroid cools down,” said Glavin.

The study was published in the Meteoritics and Planetary Science. (ANI)