NASA space scientists are puzzled after finding vital ingredients for life in a place they thought impossible. Amino acids, which are used to make proteins, were discovered in a meteorite formed when two asteroids collided.
The space crash turned the rock so hot that such building blocks for life should not be able to exist. The fact they are there boosts the chances that life was seeded from space, experts say.
NASA’s Dr Daniel Glavin, of the Goddard Space Centre, Maryland, said: “The shock of the collision heated it to more than 2,000 degrees Fahrenheit (1,093 C), hot enough that all complex organic molecules like amino acids should have been destroyed, but we found them anyway.”
The meteorite was one of a shower of stones seen to crash to Earth in a desert in Sudan in October 2008. In a rare occurrence, the asteroid, six to 15 ft wide, that produced the shower was spotted in space just days before the impact.
Dr Peter Jenniskens, of alien-hunters the SETI Institute, California, approached NASA to suggest searching for amino acids in the carbon-rich meteorite debris.
Astronomers knew that the asteroid, dubbed 2008 TC3, had been involved in an unusually violent collision in the distant past, thanks to it containing minerals that only form under high temperatures, and so were not expecting to find the acids. But to their surprise they found 19 different amino acids which they are certain are not due to contamination once it had landed on Earth.
Instead they believe the amino acids may have been created once the asteroid had cooled down after its cosmic collision.
Dr Glavin said: “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.”
Amino acids are used to make proteins, the workhorse molecules of life, used in everything from hair to enzymes. Just as 26 letters of the alphabet are arranged in limitless combinations to make words, life uses 20 different amino acids in a huge variety of arrangements to build millions of different proteins.
The NASA results are published this week in the journal Meteoritics and Planetary Science.
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