Could this be panspermia?
If it were panspermia by an alien race, perhaps they know of an impending doom on the earth, and are throwing some life here that can live on the new earths surface? A wild notion, but just a conversational piece...
Anyway here are a few more links
Does this article rule out the fact that this stuff can grow and metabolise at 300 celsius? Are there spores on earth that can do that?