In a ground-breaking announcement from NASA,  the Martian rover, Curiosity, has discovered organic molecules on the surface of Mars. The Curiosity Rover was launched in 2011 and has spent the last five years exploring the Martian surface in the hopes of assessing whether Mars ever had an environment able to support microbes, life forms which are too small to be seen with the naked eye.

The molecules do not necessarily mean that life was, or still is, present on Mars. Their existence merely indicates that the building blocks for life are present on the Red Planet. Microbes are commonly associated with life, however can also be formed by non-biological processes. Despite its dry, barren surface, Mars has ice underground and at its polar ice caps, and scientists speculate that it is likely that there was once liquid water present on the surface. These factors combine to increase the likelihood of life on the planet at some point in time, as well as indicating that there is potential for the planet to be increasingly hospitable to future human exploration.

The second announcement from the space agency was regarding methane, first detected in the Martian atmosphere by Curiosity in 2014. Methane is the simplest organic molecule and is perhaps best known as a greenhouse gas here on Earth. Methane’s presence on Mars is something that has continued to puzzle scientists as a vast majority of methane on Earth is produced by biological organisms, while the source of methane on Mars is still undetermined. As methane on Mars has a short lifespan of only 300 years, the molecule’s presence indicates that there is a source of renewal. NASA’s announcement today also unveiled research, suggesting that it is likely that seasonal changes release the gas from where it resides underneath the surface of the planet, where Curiosity detected it.

“With these new findings, Mars is telling us to stay the course and keep searching for evidence of life,” said Thomas Zurbuchen, associate administrator for the Science Mission Directorate at NASA headquarters in Washington. “I’m confident that our ongoing and planned missions will unlock even more breathtaking discoveries on the Red Planet.”