Did you know that there are AI models out there trained to detect alien life? No, not the little green people flying around in UFOs. (We won’t need an AI model to identify one of those!) We’re talking about traces of living things on other planets 

This is the field of astrobiology in which scientists scour the planets around us for signs of life—anything from a shell to a trace of an extinct plant. While it’s not nearly as exciting as fighting off an alien invasion with laser guns, these “hints” of life are still considered “aliens” from another world.

So, where do you start to look for remains of ancient life? The same place you do on Earth; in the ground. Since we can’t get an industrial digger up to Mars, we have to make do with what our rovers see and the little samples they collect. There’s a lot of stuff in dirt, however, and it can be hard to tell what was made from an ancient animal and what is just space grit.

This is where artificial intelligence comes in. Instead of having a human look through the dirt themselves, astrobiologists want to send a rover with a built-in AI module to study dirt samples at a molecular level and deduce whether they contain signs of biological life. They can check for signs of ‘modern’ life, which usually involves molecules that make up teeth or hair. Or, they can look for signs of ‘ancient’ life; compounds you’d only find if something once lived there. Coal, for instance, is created from trees that died millions of years ago, so finding coal on Mars is a sign that something grew there once.

So how good is this dirt-analyzing AI? Astrobiologists put the model to the test on Earth’s dirt and found that it had a 90% accuracy rate when detecting signs of modern and ancient life. It also could distinguish if it was given a sample with only abiotic molecules in it–that’s the fancy way of saying ‘stuff that isn’t part of biology’.

Are we close to finding alien life? Maybe not for a while. After all, astrobiologists need to find a way to put this AI on a rover, ship it into space, and land it on another planet so it can do its job. But if they’re successful, this AI model may help us make a breakthrough in answering the question; was there once life on Mars?