Similarly, with fullerenes, a form of carbon molecule with hollow atoms discovered in the 1980s and now used in biomedicine.

They are also the most common class of carbon molecule in meteorites and in cometary and asteroidal dust (cosmic dust).

The experimental evidence, a strong peak at 720 atomic mass units, indicated that a carbon molecule with 60 carbon atoms was forming, but provided no structural information.

Those traits together mean the thin, one-atom-thick sheets of carbon molecules can be applied in lots of ways.

Scientists say life would require three prerequisites: water, energy and complex carbon molecules.