Nasa's Curiosity rover has made an exciting nitrogen discovery on the surface of Mars.
When the rover analysed dust and rock samples it detected nitric oxide.
It's an important discovery because nitric oxide is essential for all forms of life, but it needs to be in the right form to be useful.
The experts found the signs of the nitrates in dust after the rover had drilled mudstones.
Scientists are excited because it adds to the evidence that the planet may have had the conditions necessary to sustain life in its past.