While exploring a crater on Mars that could give scientists insight into life that may once have existed there, NASA said its Perseverance rover made an unprecedented discovery. The rover, which landed on the Red Planet in 2021 specifically to explore the ancient Jezero crater, found a mysterious light-colored boulder earlier this month that was the first of its kind seen on Martian land.
Perseverance encountered the boulder while traversing the Neretva Vallis, a dried-up river delta that flowed into the crater billions of years ago, en route to an area within the rim where rock outcrops are being examined for sediment that could shed light on Mars’ history. NASA said. The rover had changed course along the way to avoid rough terrain when, taking a shortcut through a dune field, it reached a hill that scientists have named Mount Washburn.
The hill was covered in boulders, some of which were described by NASA as belonging to “a type never before observed on Mars.”
One small boulder especially intrigued the scientists working with Perseverance from Earth. The speckled and strikingly light-colored rock was about 18 inches wide and 16 inches high and was spotted among a field of darker boulders on the hillside.
NASA/JPL-Caltech/ASU/MSSS
“The diversity of textures and compositions at Mount Washburn was an exciting discovery for the team, because these rocks represent a grab bag of geological gifts brought down from the crater rim and possibly beyond,” said Brad Garczynski of Western Washington University, who co- is leading the current Perseverance mission, in a statement. “But among all these different rocks, there was one that really caught our attention.”
Garczynski and his team named the mysterious boulder Atoko Point, and a deeper examination of the rock using the rover’s instruments suggested that it was composed of the minerals pyroxene and feldspar. NASA said the size, shape and overall arrangement of minerals in Atoko Point, as well as the boulder’s potential composition at a chemical level, puts the rock “in a class of its own” in terms of Martian sediment, at least among those already known to scientists.
Pyroxene and feldspar are minerals 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 detected at Atoko Point may have come from magma that originated beneath the surface of Mars and became exposed over time at the edge of Mars. the Jezero crater due to erosion.
Other members of the team suggested that the boulder might have seemed out of place on Washburn Hill if it had really been produced on another part of the planet and moved with the ancient river channel to its current location on the edge. But NASA said all Perseverance scientists believe more rocks with a similar composition must exist elsewhere on Mars.
NASA/JPL-Caltech
The rover discovered Atoko Point in the middle of its fourth “campaign” on Mars, which focuses on finding evidence of carbonate and olivine deposits in the interior of the Jezero Crater. Both groups of minerals are found on Earth, with carbonate typically found in deposits near the shores of lakes and olivine typically associated with volcanic activity.
They are of interest to scientists studying Mars – and both have already been observed by Perseverance – because of their ability to encapsulate remnants of the past for long periods of time. Identifying carbonate in Mars’ 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 Mars’ climate may have been conducive for organic compounds, such as flowing water, and, potentially, life.
Scientists say learning about the composition of Mars, and what it may have looked like long ago, could help them figure out whether the planet’s current landscape could ever be habitable for humans. It could also provide important clues about the origin and evolution of life on Earth.