What hydrocarbon species have been detected on Mars though, other than a possible (and controversial) trace of methane?

Such observations were regarded as important in finding possible traces of the animals' preadaptation to crawling on land.

But, because it was the only possible trace, he turned in the direction it pointed.

The set of possible traces of unitary matrices belonging to the group SU(3) forms a deltoid.

Marigold patted her lips with her table napkin, removing the last possible trace of after-dinner mint.

Extensive quarrying around the site has removed any possible traces of a moat.

He had just found a possible first trace - the first sign - of his parents' fate!

Fischer reports that on side b pencil rubbings reveal possible traces of an inscription at the edge of the burnt area.

It is not required that all possible traces be present (which would be countably infinite for a net with a loop).

According to the same author, there are possible traces of Minoan and Mycenaean Greek influence in the island.