What does that mean? The European Space Agency says it’s a sign of organic material.

Adding even further to the excitement, the Rosetta spacecraft orbiting the comet is reported to have picked up organic material that look resembles viral particles. It also has icy “seas” and craters with small lakes and organic debris.

The science is a little unusual, according to ESA scientist Chandra Wickramasinghe: “The dark material is being constantly replenished as it is boiled off by heat from the sun. Something must be doing that at a fairly prolific rate.”

Read more from The Guardian.