Meteorites, or space rocks, revealed amino acids which make up proteins, essential building blocks of life that could have been an important source of the organic compounds of life on Earth.

Key DNA components exist in extraterrestrial meteorites, and another team has also discovered molecules linked with a vital ancient biological process.

What this means is that the earliest forms of life on earth could have been made partially from materials delivered to planet Earth from space.

Researchers found a variety of nucleobases, key DNA ingredients, in meteorites before and were trying to figure out if they are of biological origin, but it had been difficult to prove if the molecules were merely contamination from sources on Earth.

Scientists sampled a dozen meteorizes using the latest scientific analysis techniques to confirm if any nucleobases were of extraterrestrial origin. They discovered three rare nucleobase compounds.

"...it looked like the nucleobases in these meteorites were terrestrial contamination - these results were a very big surprise for me," NASA chemist and astrobiologist Michael Callahan, also lead author of the study, told Space.com.

The finding reveal that meteorites may have been molecular tool kits, providing the essential building blocks for life on Earth, chemist Jim Cleaves of Carnegie Institution of Washington told Space.com.

"All this has implications for the origins of life on Earth and potentially elsewhere," said Callahan.

NASA NASA