New research from a team of scientists at Penn State found that Mars could have once hosted flowing rivers, a potential indicator of ancient extraterrestrial life.

The team of researchers analyzed Curiosity rover data and the study was published recently in Geophysical Research Letters. The study determined that many of the craters covering Mars could have been habitable rivers.

“Mars could have had far more rivers than previously believed, which certainly paints a more optimistic view of ancient life on Mars,” Penn State geosciences professor Benjamin Cardenas, the study’s lead author, said in a statement. “It offers a vision of Mars where most of the planet once had the right conditions for life.”

While evidence for rivers on Mars has been known since the Mariner 9 mission, the recent study suggests that rivers may have been more widespread than previously believed. This study was the first to map the erosion of ancient Martian soil by training a computer model on a combination of satellite data, Curiosity images, and 25-year-old scans of Earth’s own rock deposits.

Researchers stated that 3D scans from beneath the Gulf of Mexico seafloor provided a benchmark to compare Mars stratigraphy – layers of rock deposited over millions of years. The team of scientists simulated Mars-like erosion over millennia using Earth scans to show that common crater formations could be the remnants of ancient riverbeds.

According to the study, this is the first time that data on erosional landforms collected by Curiosity at Mars’ Gale Crater have been interpreted as possible river deposits. As water is a crucial component of life, researchers responsible for the study have theorized that this could serve as evidence for the existence of ancient extraterrestrial organisms.

The scientists also claimed that the findings may indicate the presence of more undiscovered river deposits elsewhere on the planet and that a large portion of Mars may have been built by rivers during a more habitable period of the planet’s history.

“We see signs of this all over the planet,” Cardenas said. “What we see on Mars today is the remnants of an active geologic history, not some landscape frozen in time.”

The recent findings are among a series of discoveries that have heightened researchers’ interest in Mars and NASA astronauts have aspirations of soon visiting the red planet.

For example, data from NASA’s Perseverance rover led researchers to the conclusion that organic molecules were present in rocks where a lake long ago existed on Mars. This study, concluded in July 2023, was another piece of evidence that Mars once hosted extraterrestrial life.

“Mars is exciting, and still may have signs of life,” Andrew Steele, a Carnegie Institution staff scientist who has investigated the Mars rock, said in a statement at the time. “But it is also teaching us about how the building blocks of life can form.”

With its Artemis program, NASA has resumed lunar missions for the first time in decades and plans to send astronauts to the moon in 2025. Once there, NASA plans to establish a permanent human presence on or around the moon which will serve as a base of operations for future Mars missions.