Space research

DTU researchers are "closer than ever" to proving that there has been life on Mars

Leopard-spotted deposits in fossilized mud on Mars may have been left behind by living organisms. But to be absolutely sure, we need to bring the samples down to Earth, researchers from DTU and NASA write in the scientific journal Nature.

The Perseverance rover has been searching for signs of past life on Mars since 2020. The PIXL instrument at the top of the rover was developed in collaboration with DTU Space. Photo: NASA/JPL-Caltech/MSSS

Wednesday 10 September 2025

Simon Koefoed Toft

For five years, NASA’s Mars rover Perseverance has been driving around the red planet with equipment from DTU on board. Using advanced instruments and cameras, it is searching for signs of past life.

And it may already have found them. In an article published in the renowned scientific journal Nature, a team of researchers, including several DTU scientists, shows that Perseverance, using its PIXL instrument, has found chemical compounds that we typically associate with biological life.

This is not definitive proof that there has been life on Mars, says Professor John Leif Jørgensen of DTU Space, who has contributed key technology to PIXL and is co-author of the article. But it is closer than ever before, he believes:

"If the same findings had been made here on Earth, we would unequivocally say that they were traces of very early life billions of years ago. But because it is on Mars, where no life is known to exist today, we cannot say with 100 percent certainty that this is evidence of past life on Mars. However, we can say that we have not been able to find any other explanations for our data than that there has been life on Mars."

The remarkable findings have been reported previously, but have now been analyzed further and published in Nature, which is considered to be one of the most recognized peer-reviewed scientific journals in the world.

And this will spark a major debate in scientific circles, John Leif Jørgensen predicts:

"Discoveries like this can really cause a stir, because if there has been life on Mars, it challenges our entire understanding of the universe. Our results have already been peer-reviewed, but we naturally invite everyone with insight into the field to approach them with an open mind and a critical eye. It is in the nature of science that we question each other's work."

Facts

About DTU's contribution

DTU Space has played a central role in the development of the advanced PIXL instrument, which is mounted on the end of Perseverance's robotic arm. PIXL has been used to examine and analyze the chemical compounds in the Jezero crater.

DTU researchers have worked closely with NASA’s Jet Propulsion Laboratory to design and build the PIXL instrument and have supplied several of the subsystems:

The hyperspectral camera, which can "see" ultraviolet, visible, and infrared light. The camera is used to provide visual context for the other instruments, to determine the geological composition of rock types, to measure grain sizes, and to identify the target areas to be scanned by the X-ray microscope.
The two structured lasers, which, together with the context camera, accurately measure the distance to the target.
The ultra-precise navigation system "Terrain Relative Navigation", which uses the camera system to ensure, among other things, that PIXL scans the desired area and does not collide with the uneven rocks.

All three systems are key technologies that PIXL cannot function without.

DTU researchers perform all image interpretations from the systems and have thus played a fundamental role in understanding the data on which the new scientific article is based.

Home to Earth

The promising chemical signatures have been found on a rock in a now-dry river delta that flowed into a crater on Mars called Jezero.

On the banks of the river, fossilised material has been found embedded in petrified mud, containing elements that here on Earth would be interpreted as signs of the former presence of microorganisms.

It is these chemical compounds, including oxygen, organic carbon, hydrogen and phosphorus, that the researchers in their article refer to as "potential biosignatures" – i.e. evidence of biological life.

The big question is whether there could be other explanations for how these particular chemical compounds ended up on the dried-up riverbank:

"The research team has been searching intensively for a non-biological process that can explain what we have seen on Mars. But so far, we have not been able to come up with a plausible explanation that does not involve life," says John Leif Jørgensen.

However, in order to determine with certainty whether the substances originate from living organisms and to establish their age, we need to be able to examine them thoroughly in a laboratory:

"We can only determine this conclusively if we bring the samples collected from Mars back to Earth for further examination. That is why NASA has proposed the Mars Sample Return mission, to which we are also contributing, and which will bring our samples back to Earth. So we are closer than ever to a definitive answer," says John Leif Jørgensen.

The Mars Sample Return mission has not yet been finally approved, but is being planned in collaboration between NASA and the European Space Agency, ESA.

Find the complete research article in Nature and DTU Orbit.

Contact

John Leif Jørgensen Professor and Head of Measurement and Instrumentation National Space Institute jlj@space.dtu.dk

David Arge Klevang Associate Professor National Space Institute Phone: +45 45253609 dakp@dtu.dk