A new analysis of decades-old research suggests that NASA’s first rover mission to the Red Planet 20 years ago may have explored the edges of a Martian ocean the size of California.
In 1997, the space agency sent its first rover named Sojourner to Mars by the Pathfinder spacecraft in an attempt to test the Martian mega-flood hypothesis, a theory that explains how the planet’s large channels – the largest in the Solar System – came into being following a cataclysmic flood around 3.4 billion years ago. Sojourner took images from areas around a marine spillover landscape that showed the channels to be 10 times shallower than depths estimated by the hypothesis when compared against orbital observations of the channels from 50 years ago during the Mariner 9 spacecraft. Many within the scientific community argued that the channels were instead created by lava flow or other debris.
Writing in Scientific Reports, researchers from the Planetary Science Institute reanalyzed previous research and argue that the channels were in fact carved by an ancient massive flood.
“Our paper shows a basin, with roughly the surface area of California, that separates most of the gigantic Martian channels from the Pathfinder landing site. Debris or lava flows would have filled the basin before reaching the Pathfinder landing site. The very existence of the basin requires cataclysmic floods as the channels’ primary formational mechanism” said study author Alexis Rodriguez in a statement.
Researchers say that the landing site of the rover was a spillway of the ancient sea. The presence of this sea – which is similar to the Aral Sea in that both lack distinct shorelines – could have prevented certain fluvial flows and instead allowed shallow spillovers.
“The basin is covered by sedimentary deposits with a distribution that precisely matches the inferred extent of inundation from potential catastrophic floods, which would have formed an inland sea,” Rodriguez said. “This sea is approximately 250 kilometers (155 miles) upstream from the Pathfinder landing site, an observation that reframes its paleo-geographic setting as part of a marine spillway, which formed a land barrier separating the inland sea and a northern ocean."
Furthermore, the prospect that Mars could have been sculpted by flowing water means that there is a possibility that life may have once thrived on it.