This requires a mutli-disciplinary approach to research across the physical, life, chemical, Earth, social and economic sciences.

UNESCO: Providing scientific leadership towards Rio+20

We know from scientific studies on Earth that, given the right chemical elements and some energy, organic compounds form.

CNN: Three more homes for life in the universe?

There was also a widely shared view that so long as any nation on earth retained the capability to manufacture chemical weapons this sort of residual deterrent stockpile would be required.

CENTERFORSECURITYPOLICY: Center for Security Policy | Banning Chemical Weapons: Negotiating Unilateral US Disarmament

Here's one example why we should care: in 1977, diving in the human occupied vehicle Alvin, scientists investigating a volcanic ridge 2500 m (1.5 miles) below sea-level found something totally unexpected -- lush ecosystems thriving at hydrothermal vents fueled by chemical energy released from the Earth's interior.

CNN: Probing the ocean's undiscovered depths

"The early Earth could well have been seeded with the chemical building blocks you need for life to start, " said Dr. Smith.

WSJ: Russia Meteor Was Largest in More Than a Century

But this theory predicts Earth and its satellite should have a quite different chemical make-up - and the data shows in fact they are very similar.

BBC: Moon formation: New spins put on old questions

Chemical analysis of martian meteorites has revealed that Mars boasts more manganese than Earth.

CNN: Researcher: Mars rock varnish hints of life

Astrobiologists like the idea that life can be built with a completely different set of chemical building blocks because it means that life could then exist in all sorts of places that Earth-based living things would find intolerable.

FORBES: Why Those Cool Arsenic Bacteria Are Not A New Form Of Life