UNITED NEWS INTERNATIONAL (UNI) — Scientists say they’ve found the building blocks for life on Mars.

NASA’s Curiosity rover discovered organic matter on the surface of the Red Planet.

The rover drilled into the Gale Crater and collected rock samples some 3 billion years old.

It took a long time for scientists to decipher the rover’s tests but researchers finally described the results in a study published June 7 in the journal Science.

The soil samples contained organic carbon molecules.

Carbon could have come from one of three places: meteorites, rock-forming processes, or it could be all that’s left from organisms that once lived in a Martian lake.

Whether-or-not life ever existed on Mars remains a mystery but the Curiosity rover found another intriguing clue.

Methane — which is also organic — is fluctuating in Mars’ atmosphere.

Scientists say it’s leaking from the surface and might be coming from underground lakes.