Scientists have found evidence of ancient sea floor hydrothermal deposits on Mars, a major breakthrough that could help us understand how life began here on Earth. The report is based on observations by the Mars Reconnaissance Orbiter circling the Red Planet, which found huge deposits in a basin in the southern end of the planet.

Scientists think this data shows that deposits were formed by heated water from a place in the crust of Mars that had active volcanoes many, many years ago. Scientists are excited about what this discovery could tell them about how life began on Earth, as experts think that these hydrothermal vents are the kind where life first emerged eons ago on Earht, but it’s been tough to study what the conditions were like billions of years ago.

These Martian deposits are probably about 3.7 billion years old. Today, the planet doesn’t have any standing water or active volcanoes, but scientists think that long ago it may have been a very active place and could have even harbored life.

“The Eridania region in the southern highlands of Mars once contained a vast inland sea with a volume of water greater than that of all other Martian lakes combined,” reads the abstract from the paper, which was published in Nature Communications. “Here we show that the most ancient materials within Eridania are thick (>400 m), massive (not bedded), mottled deposits containing saponite, talc-saponite, Fe-rich mica (for example, glauconite-nontronite), Fe- and Mg-serpentine, Mg-Fe-Ca-carbonate and probable Fe-sulphide that likely formed in a deep water (500–1,500 m) hydrothermal setting. The Eridania basin occurs within some of the most ancient terrain on Mars where striking evidence for remnant magnetism might suggest an early phase of crustal spreading. The relatively well-preserved seafloor hydrothermal deposits in Eridania are contemporaneous with the earliest evidence for life on Earth in potentially similar environments 3.8 billion years ago, and might provide an invaluable window into the environmental conditions of early Earth.”