An odd rock spotted on Mars

 Perseverance rover spots an unusual zebra stripes rock on Mars          

NASA's Mars Perseverance rover captured an image of a black-and-white striped rock using its Left Mastcam-Z camera. Mastcam-Z is a pair of cameras located high on the rover's mast. This image was acquired on 13 Sep, 2024 (Sol 1268) at the local mean solar time of 12:40:29. The Perseverance rover has spotted a black-and-white striped rock on Mars, amazing scientists and the general public. The rover made the discovery while climbing the steep slopes of the Jezero Crater and marching towards its rim. While the initial ascent was slower, Perseverance is now moving remarkably faster and has cruised along a flatter stretch. The Freya Castle is the only one of its kind in the region of the Jezero Crater, but more of them might be found once the rover moves to a higher region.

Last week, team scientists and the internet alike were amazed when Perseverance spotted a black-and-white striped rock unlike any seen on Mars before. While the rover was travelling through a pebbly terrain of Jezero, team members spotted a cobble in the distance that looked unusual. Low-resolution Navcam images showed that it likely had an unusual texture. They named it Freya Castle and planned a multispectral observation using the Mastcam-Z camera. It has now nearly been a month since the rover began its climb up the steep slopes leading to the crater rim, on the hunt for ancient rocks which could teach us about early Martian history. While these tricky slopes made for a slow initial ascent, drive progress has improved greatly in recent days, as Perseverance has cruised along a flatter stretch. From this overlook, the rover can now spot landmarks from earlier in the mission like the iconic Kodiak butte on the hazy horizon, thick with dust from nearby dust storms.

While driving across unremarkable pebbly terrain, beady-eyed team members spotted a cobble in the distance with hints of an unusual texture in low resolution Navcam images, and gave it the name Freya Castle. The team planned a multispectral observation using the Mastcam-Z camera in order to get a closer look before driving away. After the Perseverance rover had moved on in its journey, data downlinked a couple of days later surprised the researchers. Clearer photos of the rock showed that Freya Castle is around 20 cm across in size and has alternating black and white stripes. 

When this data was downlinked a couple days later, after Perseverance had already left the area, it became clear just how unusual it was. Freya Castle is around 20 cm across, and has a striking pattern with alternating black and white stripes. The internet immediately lit up with speculation about what this "zebra rock" might be. Scientists say that the rock is unlike any other ever found not only in the Jezero Crater but all of Mars. While they are not sure of its chemical composition, as per early interpretations igneous and/or metamorphic processes could have created its stripes. 

The Freya Castle is a lone stone and completely different from the underlying bedrock. Experts think that the rock likely rolled downhill from somewhere higher where more such rocks might be present. The science team thinks that this rock has a texture unlike any seen in Jezero Crater before, and perhaps all of Mars. Our knowledge of its chemical composition is limited, but early interpretations are that igneous and/or metamorphic processes could have created its stripes. Since Freya Castle is a loose stone that is clearly different from the underlying bedrock, it has likely arrived here from someplace else, perhaps having rolled downhill from a source higher up. This possibility has researchers excited, and they hope that as they continue to drive uphill, Perseverance will encounter an outcrop of this new rock type so that more detailed measurements can be acquired.

Freya Castle is merely the latest in a series of intriguing rocks found recently. Ever since arriving in the vicinity of the crater rim, the team has noticed an increased variety of rocks, such as the diverse collection of boulders at Mount Washburn. As Perseverance continues to travel upwards, scientists are excited by what more it might find. Finding more such rocks will help them acquire more detailed measurements. This is not the first time that a fascinating rock has been found on Mars. The vicinity of the crater rim had earlier presented an increased variety of rocks, such as the diverse collection of boulders at Mount Washburn. A few weeks back, Curiosity Rover drove over some stones, cracking open one of them and yellow sulfur crystal tumbled out, a first for the red planet. “Finding a field of stones made of pure sulfur is like finding an oasis in the desert,” Curiosity’s project scientist, Ashwin Vasavada of NASA’s Jet Propulsion Laboratory in Southern California, said.