NASA's Perseverance rover made a discovery on the Martian surface, uncovering a skull-shaped rock formation dubbed Skull Hill. According to the New York Post, the rover spotted this unusual elevation on April 11 while descending a ridge known as Witch Hazel Hill within the Jezero Crater.
"Visually, it doesn't look like anything in its surroundings," said Margaret Deahn, a Ph.D. student at Purdue University working with NASA, according to the New York Post. "It looks as if it had been dropped there from somewhere else."
Skull Hill stands out sharply against the surrounding light-toned terrain due to its dark color and angular shape. The rock is also covered with small pits, which may be the result of wind erosion or softer minerals that were once embedded in the rock being worn away. These features led scientists to initially speculate that it might be a meteorite.
Using the rover's SuperCam laser to verify the chemical composition of a nearby similar rock, NASA scientists found that Skull Hill lacked the high iron and nickel levels typical of space rocks, ruling out the meteorite theory.
Another theory is that Skull Hill is an igneous rock formed when lava or magma cooled, possibly millions or billions of years ago. Such rocks are common on both Earth and Mars and often contain elements like iron and magnesium, which could explain the dark color of Skull Hill. Alternatively, it could be an igneous rock eroded from a nearby outcrop or ejected from an impact crater.
"Luckily for us, the rover has instruments that can measure the chemical composition of rocks on Mars," Deahn noted, signaling that more tests are likely to come to determine Skull Hill's origins.
The discovery of Skull Hill adds to a series of unusual Martian formations that provide scientists with insights into the geological history of the Red Planet. The Jezero Crater, where the formation was found, is a dry depression north of the Martian equator that likely housed a lake billions of years ago. This makes it a site for exploration in the quest to understand Mars's past environments and assess its potential habitability.
Since landing in the Jezero Crater in February 2021, the Perseverance rover explored a variety of Martian rock types. The rover collected samples from different rocks, analyzed others in detail, and used its laser for remote sensing to contribute to its key mission goals.
Understanding the composition of dark float rocks like Skull Hill will help the team reconstruct the geological story of this part of Mars—a story shaped by volcanic activity, impacts from space, the action of water or wind, or perhaps something unexpected. These findings could bring scientists a step closer to answering one of the biggest questions in planetary science: Did life ever exist on Mars?
The article was written with the assistance of a news analysis system.