After years of research and analysis, scientists state that rounded pebbles hint to flowing rivers on Mars, based on their research on tiny pieces of rock found in 2013 by the Mars Curiosity rover.
- Researchers analyzed rounded pebbles found in 2013 by the Mars Curiosity rover
- They ran simulation tests on limestone, and observed rocks in river flows in Puerto Rico and New Mexico
- They estimated that the pebbles were transported for 30 miles down the river from their source
- The rocks had lost 20% of their initial mass
It’s a major challenge to undertake the study of small pieces of rock from millions of miles away. Douglas Jerolmack from Penn State College, and Gábor Domokos from the University of Budapest set out to determine the history of pebbles based purely on their shape. In essence, they attempted to understand how far a rock has travelled down a river given its rounded edges.
Due to erosion and impact with other pebbles, the jagged shapes often become smooth after prolonged exposure to the flow of a river. They collide and scrape against each other, losing a small portion of their mass along with it. According to one of the researchers, by knowing whether a rock travelled 2 miles or 62 miles, they could understand how stable the water flow used to be on the Red Planet.
Their findings could potentially debunk theories that streams on Mars were short lived.
The rounded shape of a few pebbles found in the Gale Crate on the Red Planet suggests that a river flow might’ve been much longer than estimated. The researchers took to testing by seeing limestone fragments into a rotating, water-filled drum. This helped them estimate the volume that was chipped off by erosion.
They examined rocks from a mountain river in Puerto Rico, and stones at the Dog Canyon alluvial fan in New Mexico. The latter is reportedly much more similar to what Martian deposits once looked like. Through extensive simulation and analysis of pictures of the rounded pebbles, they began to understand that there is a certain “code”.
By looking at the shape, they could determine how much of mass was lost, and through that, for how long it rolled down the river. It’s an exceptional use of information, and a exciting proof of how small details can lead to useful knowledge about foreign environments.
But, as stated by Jerolmack, given that the Curiosity rover is a multi-billion dollar project, any data sent over should be squeezed dry of information.
Through images sent over by NASA’s Curiosity rover, and NASA’s Mars Reconnaissance Orbiter, they were able to determine that the water transported sedimentary deposition for between 500 to 650 feet. The rounded pebbles, however, could have travelled for around 30 miles down the river, given that the reduced gravity on the Red Planet is 40% less than on Earth.
That is suggested to have flown from the northern rim of Gale Crater. The exciting find may hint toward the fact that the Red Planet was in fact littered with streams, rivers, and lakes. Instead of the short-lived water flows, it may have been home to an extensive and vast system.
Image source: nasa.gov