The essentials of life

Astrobiologist Aditya Chopra is about to analyse the most primitive organisms on Earth to find the lowest common denominator of life in work that could give hints on where to look for living things on other planets.

Chopra, an ANU Honours student at Mount Stromlo Observatory in Canberra, is to analyse the chemical composition of bacteria and primitive lifeforms called archaea, the descendants of the common ancestor of all life on Earth.

He wants to find out the minimum elemental requirements of life.

"We want to see what life is made of - what is common to all life," he says. "What were the basic elements - the raw ingredients of life - back in the early days apart from carbon and hydrogen? That is the origin of life."

Chopra will collect samples of bacteria and archaea, including extremophiles, the lifeforms that thrive in punishingly hot or acidic environments.

The work could help settle the debate over whether life began on Earth or had extra-terrestrial origins, with the planet "seeded", perhaps by meteorites from Mars.

It could also point to where to look for life on Mars, and Chopra hopes to collaborate with NASA astrobiologists in future.

He plans to undertake a PhD at ANU on completion of his Bachelor of Science degree. He says the University's strength in astronomy, the earth sciences and biology makes it an ideal place to conduct astrobiology research.