NASA’s Perseverance rover stumbles upon bizarre rock formation on Mars, sparking hopes of uncovering the Red Planet’s watery past.
A rock containing many smaller round stones could indicate that there was once a large amount of liquid water on the Red Planet.
NASA’s Perseverance rover recently discovered a strange rock on Mars, which appears to be made up of small rounded stones a few hundred millimeters in diameter. The rover is exploring the Jezero Crater, a region of Mars thought to have once been a river delta. This discovery is not the first time such a strange rock has been found on the Red Planet.
The Perseverance rover is a robotic spacecraft designed by NASA to explore Mars' Jezero crater.
Launched in July 2020, it landed on February 18, 2021.
The rover is equipped with advanced instruments to study Martian geology and search for signs of past life.
Its primary mission is to investigate the crater's ancient lakebed, which may have once supported microbial life.
Perseverance carries a helicopter drone, Ingenuity, to aid in its exploration.
The Origin of St. Paul’s Bay
The Perseverance science team is trying to determine the origin of the small round stones that make up St. Paul’s Bay, which was discovered in March 2025. ‘The rock appears to be made up of smaller, round, dark gray stones each several hundred millimeters in size.’ The shapes of these small round stones vary: some are oval-shaped, some have sharp edges, and some have small holes in them.
It is possible that these spherules are concretions, formations created by groundwater moving through pores in a rock, which suggests that there might have once been abundant liquid water on Mars. However, on Earth, these spherules are also created when molten rock cools rapidly, ‘for example after a volcanic eruption.’
A Similar Discovery by Other NASA Rovers
The Mars Exploration Program is a NASA-led mission to explore Mars through robotic rovers and orbiters.
The program began with the Mariner 4 flyby in 1964, followed by the Viking missions in the 1970s.
In 1996, NASA launched the Mars Global Surveyor, which mapped the Martian surface.
Since then, several rovers have been sent to Mars, including Sojourner, Spirit, Opportunity, Curiosity, and Perseverance.
These rovers have greatly expanded our knowledge of Mars' geology, climate, and potential habitability.
NASA’s Mars rovers have also discovered a number of other strange rocks during their missions. The first pictured below were nicknamed ‘blueberries‘ and were found by the rover Opportunity. They were discovered near Fram Crater, which Opportunity explored during April 2004. ‘Opportunity launched in July 2003 and landed on the Meridiani Plain on Mars’ equator in January 2004.’
The Curiosity photographed a similar formation, known as the ‘sheepbed,’ exposed in an area on Mars called Yellowknife Bay. These small round pebbles are often found in other parts of the sheepbed as well. ‘Curiosity was launched in November 2011 and continues to explore Mars.’
A New Discovery by Perseverance
The Perseverance also discovered a sedimentary rock formation with a ‘popcorn‘ texture, which contains small rounded stones. After completing its exploration of a part of the Jezero Crater called Mt. Washburn, Perseverance headed north and reached an area in the Neretva Valley called Bright Angel, where layered, light-colored rocks are exposed on the surface.
The Perseverance rover, launched by NASA in July 2020, has made several significant discoveries about the Martian surface.
In February 2021, it found evidence of past water on Mars, including 'sedimentary rocks and a lakebed.'
The rover's findings suggest that Mars may have had a more Earth-like environment in the past, with flowing water and a stable climate.
This discovery has important implications for the search for life beyond Earth.
This story originally appeared on WIRED Japan and has been translated from Japanese.
