For example, from spectral analyses, organic molecules are known to be present in comets and meteorites.

It looks like platinum and is found in asteroids and comets.

His main research field is the observational study and theoretical modelling of the dust environment in comets.

His main research field is the study of the dust environment in comets.

He specialized in comets and discovered five of them, but practically anyone can do that.

In the 1940's, a student interested him in comets.

The double-sun system was relatively poor in comets; there were only a hundred billion of them.

Iridium is much more common in asteroids and comets than on Earth.

"How do clays and carbonates form in frozen comets where there isn't liquid water?"

The simulation does not support dynamic change of mass, in the stars planets and comets.