ALH84001 - Martian meteorite discovered in the Allan Hills ice field in Antarctica in 1984. It has been suggested that this meteorite contains evidence of martian microbial life.
Amino acids link together in chains to form proteins .
Archaea - One of three domains of life, along with the Bacteria and the Eucarya . The archaea are prokaryotic organisms which were shown to be a distinct group from the bacteria by molecular phylogeny using 16S ribosomal RNA . The archaeal domain includes many extremophilic organisms. Archean - The period in the history of the Earth from 4000 million years ago to 2500 million years ago, part of the Precambrian . The Archean is preceeded by the Hadean and followed by the Proterozoic .