A team of researchers in Germany is presenting a new method for searching for life on Mars that’s cost-effective, doesn’t require computer analysis, and could be used to locate alien life on other worlds.

Though Rovers sent to Mars by NASA are equipped with tools to search for alien life trapped in rocks at the surface, the rover isn’t sophisticated enough to detect low biomass samples. A new study, however, proposes a method of locating signs of life on the Red Planet, focusing on motility.

“Microbial motility, the directed motion of microbes under their own propulsion, can be clearly distinguished from random Brownian movement by microscopic techniques and is, therefore, a prominent biosignature of life,” the team explains in the study. “Given that it has evolved independently multiple times on Earth, motility might also be a fundamental trait of extraterrestrial life that can be exploited for its detection in a resource-depleted setting.”

Since motility in microbes is more difficult to detect on other worlds than on Earth, the team tested a means of stimulating it. Researchers tested three types of microbes and discovered that they all moved through a chemical called L-serine. This movement is known as chemotaxis, and it could serve as an indicator of living organisms on other planets.

The three microbes tested, two bacteria and one type of archaea, were chosen for their ability to survive in extreme Earth conditions that closely mimic Mars’s environment. Bacillus subtilis, for example, was chosen for its ability to withstand temperatures up to 212°F, while Pseudoalteromonas haloplanktis was selected because it resides in the cold Antarctic waters. The final microbe, Haloferax volcanii, was chosen because it can survive in highly saline environments.

To conduct the test, the team used slides with two chambers separated by a thin membrane, with the sample placed in one chamber and L-serine in the other. The results showed that if the microbes were alive and able to move, they would swim toward the L-serine through the membrane.

“This approach could make life detection cheaper and faster, helping future missions achieve more with fewer resources,” Max Riekeles, a researcher at the Technical University of Berlin, explained in a statement. “It could be a simple way to look for life on future Mars missions and a useful addition for direct motility observation techniques.