London, July 31 - Did far-off comets housing vast oceans of water during the first million years of formation harbour some kind of primitive life?

The existence of water in comets bolsters support for a possible connection between life on Earth and comets.

The theory, known as Cometary Panspermia and pioneered by Chandra Wickramasinghe and the late Sir Fred Hoyle, argues that life was introduced to Earth by comets.

'These calculations, which are more exhaustive than any done before, leaves little doubt that a large fraction of the 100 billion comets in our solar system did indeed have liquid interiors in the past,' Chandra Wickramasinghe, professor at Cardiff University and study leader, said.

The Cardiff University team has calculated the thermal history of comets after they formed from interstellar and interplanetary dust approximately 4.5 billion years ago.