NASA’s Perseverance rover has discovered a mysterious “Skull Hill” rock formation on Mars, leaving scientists puzzling over how this dark, angular structure with tiny pits ended up in an area dominated by lighter-colored terrain.

At a Glance

• NASA’s Perseverance rover discovered “Skull Hill” on April 11 while exploring Witch Hazel Hill in Jezero Crater
• The dark, angular rock with distinctive pits stands in stark contrast to the surrounding lighter-colored terrain
• Initial theories suggested it might be a meteorite, but chemical analysis has ruled this out
• Scientists now believe it may be an igneous rock formed from ancient lava flows
• Further tests are underway to determine its origins and what it may reveal about Mars’ geological history

An Unusual Discovery on the Red Planet

During its exploration of the Jezero Crater on Mars, NASA’s Perseverance rover has encountered an intriguing rock formation nicknamed “Skull Hill.” The discovery occurred on April 11 as the rover traversed an area called “Port Anson” on “Witch Hazel Hill” along the crater’s rim. Jezero Crater, a 28-mile-wide basin, is believed to have once contained a lake, making it a prime location for studying Mars’ potential past habitability and searching for signs of ancient microbial life.

“Last week, NASA’s Mars 2020 rover continued its journey down lower ‘Witch Hazel Hill’ on the Jezero crater rim,” reported Margaret Deahn, Ph.D. Student at Purdue University.

Distinctive Features That Raise Questions

What makes “Skull Hill” particularly noteworthy is its stark contrast to the surrounding Martian landscape. The formation is characterized by its dark coloration, angular structure, and numerous small pits covering its surface. These distinctive features stand out dramatically against the predominant light-colored rocky outcrops in the area. Scientists have observed that the rock appears to be out of place, suggesting it may have been transported from elsewhere on Mars, a phenomenon known as “float.”

“Alternatively, ‘Skull Hill’ could be an igneous rock eroded from a nearby outcrop or ejected from an impact crater,” explained Margaret Deahn, Ph.D. Student at Purdue University.

The pits observed on the rock’s surface may have formed through erosion or wind scouring over extensive periods, adding another layer to the mystery of this unusual Martian feature. These weathering patterns could provide valuable clues about Mars’ past environmental conditions and the geological processes that have shaped the planet’s surface over billions of years.

Scientific Theories and Ongoing Analysis

Initial speculation suggested that “Skull Hill” might be a meteorite, as its dark color resembles meteorites previously found in Mars’ Gale Crater. However, preliminary chemical analysis conducted using Perseverance’s SuperCam instrument has ruled out this possibility. The rock doesn’t contain the high levels of iron and nickel typically found in meteorites, requiring scientists to consider alternative explanations for its origin.

“Luckily for us, the rover has instruments that can measure the chemical composition of rocks on Mars,” noted Margaret Deahn.

The leading theory now suggests that “Skull Hill” is an igneous rock formed from cooled lava or magma, potentially dating back millions or billions of years. Its current location may be explained by erosion from a nearby outcrop, ejection from an impact crater, or displacement by another powerful natural event in Mars’ distant past. NASA scientists are continuing to analyze data from Perseverance’s suite of instruments to determine the rock’s precise chemical composition and origin.

Implications for Understanding Mars

The discovery of “Skull Hill” represents more than just an interesting geological curiosity. By studying unusual formations like this, scientists can piece together a more comprehensive understanding of Mars’ complex geological history. If confirmed as an igneous rock, “Skull Hill” could provide valuable insights into the planet’s volcanic past and the processes that have shaped its surface over billions of years.

Perseverance’s mission in Jezero Crater continues to yield fascinating discoveries that help scientists build a more complete picture of Mars. Each rock, formation, and soil sample analyzed adds another piece to the puzzle of the Red Planet’s history and potential to have once harbored life. As analysis of “Skull Hill” continues, it may reveal new clues about Mars’ ancient past and further our understanding of planetary geology beyond Earth.