GabyA team of astronomers at the Hong Kong Polytechnic University reports that about 3.68 billion years ago an ocean likely covered much of Mars’ northern hemisphere.
This month on the Red Planet a new year began — the 38th Martian New Year since November 12, 1956 (Mars completes an orbit around the Sun in 1.88 Earth years).
The current Martian year began with the publication of an analysis of data that Zhurong sent to Earth during its brief mission. The rover studied Mars from 2021 until excessive sand buildup on its solar panels forced it to stop operating in May 2022.
What did the scientists learn?
The university team that analyzed the rover’s data says it found new evidence supporting the long-standing idea that an ancient ocean once covered parts of Mars billions of years ago.
Since landing in one of Mars’ largest and oldest impact basins, Utopia Planitia, the Zhurong rover traveled about two kilometers, studying local geology for signs of water or ice.
By combining observations from the rover’s onboard cameras with remote-sensing data from orbiting satellites, the team identified several water-related features: crater-like cones, troughs, and sedimentary channels where they saw traces of an ancient shoreline.
The report says an ocean likely existed in northern Mars about 3.68 billion years ago. Researchers think water-related minerals, such as hydrated silica, formed on the ocean floor. The ocean then froze for roughly 10,000 to 100,000 years — a short period in geological terms — which smoothed the coastline. About 3.4 billion years ago the ocean disappeared, leaving traces of the shoreline, Live Science reported.
The presence of water in those distant times suggests Mars once had conditions that could have supported microbial life. Scientists also propose that at least part of the ocean may have migrated underground. Data from NASA’s InSight lander suggest that a large volume of water — enough to cover Mars with an ocean 1 to 2 kilometers deep — seeped into the planet’s crust and remains stored in tiny cracks and pores.
Confirming the Martian ocean will require rock samples returned to Earth. Future Mars missions could help solve the long-running mystery of why Mars lost so much water.
The study was published in the journal Scientific Reports.
