Exploring a crater on Mars that may give scientists a glimpse of life that potentially once existed there, NASA says its Perseverance rover has made an unprecedented discovery. A rover that landed on the Red Planet in 2021 specifically to probe the ancient crater Lake found a mysterious, light-hued boulder earlier this month, the first of its kind on Mars.
Perseverance hit the boulder as it passed through Neretva Vallis, a dried-up river delta that drained into the crater billions of years ago, on its way to an area inside the rim where rock outcrops are being probed for sediment that could shed light on Mars’ history, NASA said. The rover changed course along its route to avoid rough terrain as it took a shortcut across a dune field to reach a hill that scientists named Mount Washburn.
The hill was covered in boulders, some of which NASA described as belonging to “a type never before seen on Mars”.
One small boulder in particular caught the eye of scientists working with Perseverance from Earth. The mottled and strikingly light rock, measuring roughly 18 inches wide and 14 inches tall, was spotted among a field of darker boulders on the hill.
NASA/JPL-Caltech/ASU/MSSS
“The variety of textures and compositions at Mount Washburn was an exciting discovery for the team because these rocks represent a bag of geological gifts brought down from the rim of the crater and potentially beyond,” said Brad Garczynski of Western Washington University, who leads the current Perseverance mission, in a statement. “But among all the different stones, there was one that really caught our attention.
Garczynski and his team dubbed the mysterious boulder Atoko Point, and a deeper examination of the rock using the rover’s instruments indicated that it was composed of the minerals pyroxene and feldspar. NASA said the size, shape and overall arrangement of the minerals in Atoko Point, as well as the potential composition of the boulder at a chemical level, put the rock “in a league of its own” in terms of Martian sediment, at least among them. already known to scientists.
Pyroxene and feldspar are minerals that are also found in the Earth’s crust and on the Moon, according to the US Geological Survey and NASA. The space agency said some scientists on the Perseverance team speculated that the minerals found at Atoko Point may have come from magma that originated beneath the Martian surface and was exposed over time at the edge of the Lake Crater due to erosion.
Other members of the team suggested that the boulder may have appeared out of place on Washburn Hill if it was actually produced on another part of the planet and moved with an ancient river channel to its current location on the edge. However, NASA said that all Perseverance scientists believe there must be more rocks of a similar composition elsewhere on Mars.
NASA/JPL-Caltech
The rover discovered Atoko Point in the middle of its fourth “campaign” on Mars, which is focused on searching for evidence of carbonate and olivine deposits inside Jezero Crater. Both groups of minerals exist on Earth, with carbonate typically found in deposits near lake shores and olivine typically associated with volcanic activity.
They are of interest to scientists studying Mars – and both have already been observed by Perseverance – due to their ability to encapsulate remnants of the past for long periods of time. The identification of carbonate in a Martian crater could theoretically give scientists access to traces of ancient life on the planet preserved in the mineral itself, and olivine helps them understand when in history the Martian climate may have been favorable for organic compounds such as flowing water, and, potentially, life.
Scientists say that learning about the composition of Mars and what it might have been like in the past could help them determine whether the planet’s current landscape could ever be habitable for humans. It could also offer important clues about the origin and evolution of life on Earth.