The key to finding out whether or not life once existed on Mars, or could exist in the future, might come down to microscopic data.

A paper in the journal Astrobiology, says that researchers taking part in the search for life might need to rely on the chemical analysis of rock samples from the planet. This type of analysis could reveal microfossils that show whether or not there was once life on Mars simply through the presence of the element vanadium.

Luckily, the rover that NASA is planning to launch to Mars in 2020 will be equipped with the technology to do such tests there and send the results back to Earth. The paper says that the element vanadium combined with Raman spectroscopy would help confirm traces of organic material, or the very basis of life. Raman spectroscopy is the process of using lasers to identify mineral phases and their compounds as well as the organic compounds present, according to NASA. It’s a newer technology that has steadily gained support and has been considered for pre-selection sampling on other planets.

The technology can reveal the very cellular composition of samples. This comes in very handy when dealing with samples that are billions of years old. The samples aren’t identifiable on most levels because they have broken, changed and combined with other things over the years. But the Raman technology and the detection of vanadium in a sample could help confirm that it was once life.

The Raman spectroscopy technology alone could detect carbon but that doesn’t necessarily mean life. So the reason for introducing the vanadium test to the equation is to tell the microfossils from other samples that have carbon but were not once alive.

The researchers who worked on the paper propose that NASA use a technique they developed called X-ray fluorescence microscopy that looks at the elemental composition of samples. The idea is that if a sample looks like a microfossil and had carbon as well as vanadium then it would be confirmed as a life form, according to a release from the University of Kansas. This is because vanadium is present in organisms and in things like crude oil, asphalt and black shale, which form from acknowledged biological sources, said the release.

To test this theory before recommending it for future space exploration, the lead author on the paper, Craig Marshall, and his colleagues tested actual known microfossils for vanadium and used the spectroscopy technique. These were microfossils that were already known to have contained life. Conducting this test and finding that the vanadium technique did help them properly identify the microfossils solidified the recommendation.

Marshall was hoping that the paper would grab NASA’s attention and that they would maybe take the research into account when deciding how to move forward with the Mars exploration missions, according to the release.