Australian meteorite behind 'space DNA' discovery

August 10, 2011

Researchers have discovered some of the building blocks of DNA found on meteorites actually came from space. Picture: NASA

A METEORITE which crashed in Australia more than four decades ago has led to a major new discovery about the nature of humankind.

Writers and filmmakers have for decades hypothesised about little green men "out there" somewhere, but it turns out alien life may actually exist closer to home.

Much, much closer.

NASA overnight said researchers had discovered that some of the building blocks of DNA found in meteorites were actually created in space — lending weight to the idea that life on Earth began with materials from the cosmos.

Scientists were previously unsure if the meteorites had brought the materials with them, or been "contaminated" by humans or animals after landing.

Dr Michael Callahan of the agency's Goddard Space Flight Centre said it was the famous Murchison meteorite which led to the discovery.

"There's a meteorite that landed in 1969 in Murchison in Victoria. It's actually the most well studied meteorite for organic molecules," he told

"It's kind of like the benchmark meteorite that people look at for organic molecules."

To prove the meteorites hadn't been contaminated, Dr Callahan and his team looked at soil and ice samples from near the Murchison crash site and another in Antarctica.

"We compared terrestrial samples to our meteorite result and they looked very different," he said.

"It's kind of given us another clue that these compounds looked indigenous to the meteorite and it’s not something like contamination."

Dr Callahan said he was stunned to have stumbled upon another missing piece of the puzzle of life's origins.

"I was shocked," he said.

"I was very surprised. I didn't believe it at first. I didn't think my result was real.

"I took a lot of time to verify the results, through lots of control samples and state of the art analysis. It took me about a year to convince myself that was I was looking was real, but it was."

Dr Callahan's discovery has led some to question whether other planets might contain the same building blocks for life as those that exist on Earth, however the scientist said it was not a given.

"The likelihood of life elsewhere, the possibility does increase a little bit," he said.

"(However) it takes a lot of steps to go from building blocks to life."