Jump to content

Recommended Posts

  • Publishers
Posted

3 min read

Spheres in the Sand

A close-up color photograph from the Martian surface shows an overhead view of a patch of ground covered in what looks like very coarse, rust-colored sand, with numerous rocks in various colors resting atop the sand. Large pale-orange rocks, knobby and lined with small fractures, dominate the upper right and left corners of the frame. Most of the rest of the image is highlighted by dozens of smaller rocks, about half of them pale gray and nearly spherical, resembling dust-covered blueberries or frozen peas.
NASA’s Perseverance rover captured this image of spherule-bearing regolith at Rowsell Hill using its arm-mounted WATSON camera on July 5, 2025 — Sol 1555, or Martian day 1,555 of the Mars 2020 mission — at the local mean solar time of 12:46:29. WATSON (Wide Angle Topographic Sensor for Operations and eNgineering) is a close-range color camera that works with the rover’s SHERLOC instrument (Scanning Habitable Environments with Raman and Luminescence for Organics and Chemicals); both are located on the turret at the end of the rover’s robotic arm.
NASA/JPL-Caltech

Written by Andrew Shumway, Postdoctoral Researcher at the University of Washington

It is not common for a rover to spot nearly perfect spheres in the soil beneath its wheels. Over two decades ago, the Opportunity rover famously discovered spherules made of hematite (nicknamed “blueberries”) near its landing site in Meridiani Planum. More recently, the Perseverance rover has similarly encountered spherules embedded in bedrock and loosely scattered throughout the region informally called “Witch Hazel Hill.” In a previous blog post, we described Perseverance’s investigations of a spherule-bearing outcrop at the “Hare Bay” abrasion patch, where the team later collected a core. With the “Bell Island” sample added to the rover’s collection, the science team next decided to take a closer look at loose spherules in the area, which appear to have eroded out of the nearby bedrock.  

On Sol 1555, while the United States was celebrating the Fourth of July with hotdogs and fireworks, Perseverance was hard at work studying spherule-rich regolith at the target “Rowsell Hill” using the proximity instruments on its robotic arm. SHERLOC’s Autofocus and Context Imager and WATSON camera both captured high resolution pictures of the target (shown above), while PIXL measured the elemental makeup of the spherules and surrounding grains. 

Despite their superficial similarity to Opportunity’s “blueberries”, the spherules at “Rowsell Hill” have a very different composition and likely origin. In Meridiani Planum, the spherules were composed of the mineral hematite and were interpreted to have formed in groundwater-saturated sediments in Mars’ distant past. By comparison, the spherules in “Rowsell Hill” have a basaltic composition and likely formed during a meteoroid impact or volcanic eruption. When a meteoroid crashes into the surface of Mars, it can melt rock and send molten droplets spraying into the air. Those droplets can then rapidly cool, solidifying into spherules that rain down on the surrounding area.  Alternatively, the spherules may have formed from molten lava during a volcanic eruption. 

With these new data in hand, the Perseverance science team continues to search for answers about where these spherules came from. If they formed during an ancient impact, they may be able to tell us about the composition of the meteoroid and the importance of impact cratering in early Mars’s history. If they instead formed during a volcanic eruption, they could preserve clues about past volcanism in the region around Jezero crater. Either way, these spherules are a remnant of an energetic and dynamic period in Mars’ history! 

Share

Details

Last Updated
Jul 29, 2025

Related Terms

View the full article

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Similar Topics

    • By NASA
      Curiosity Navigation Curiosity Home Mission Overview Where is Curiosity? Mission Updates Science Overview Instruments Highlights Exploration Goals News and Features Multimedia Curiosity Raw Images Images Videos Audio Mosaics More Resources Mars Missions Mars Sample Return Mars Perseverance Rover Mars Curiosity Rover MAVEN Mars Reconnaissance Orbiter Mars Odyssey More Mars Missions Mars Home 2 min read
      Curiosity Blog, Sols 4600-4601: Up and Over the Sand Covered Ramp
      NASA’s Mars rover Curiosity acquired this image using its Left Navigation Camera on July 13, 2025 — Sol 4598, or Martian day 4,598 of the Mars Science Laboratory mission — at 15:24:10 UTC. NASA/JPL-Caltech Written by Sharon Wilson Purdy, Planetary Geologist at the Smithsonian National Air and Space Museum
      Earth planning date: Monday, July 14, 2025
      The Curiosity rover continues to navigate through the region of Mount Sharp characterized by the boxwork terrain.  After successfully completing a drive of about 34 meters over the weekend (about 112 feet), the rover parked near the edge of a smooth, sandy stretch at the base of a ridge that leads to the most prominent and complex network of boxwork structures seen so far.
      Due to the lack of exposed bedrock in the immediate workspace, the science team opted to give some of the rover’s contact science instruments a break. With the dust removal tool (DRT) and APXS instruments stowed, the extra energy allowed the Mars Hand Lens Imager (MAHLI) to take high resolution images of “Playa de la Gallina” to survey the uniform, smooth surface consisting of sand and pebble-sized material.
      The ChemCam and Mastcam teams scheduled several observations in this two-sol plan that further investigated the rocks and structures in our immediate vicinity and surroundings. ChemCam LIBS was used to target “El Olivo” to determine the chemistry of the bumpy textured bedrock near the rover, which was also imaged by a Mastcam stereo mosaic. Additional Mastcam stereo mosaics include fractures at “El Corral” and linear troughs at “Chapare.” Further away, ChemCam’s Remote Micro Imager (RMI) will provide insight into an intriguing section of scoured features within the Mishe Mokwa butte.
      The environmental working group continues to keep an eye in the sky and planned a supra-horizon movie and a dust-devil survey as part of their ongoing monitoring campaign of the atmospheric conditions in Gale Crater.
      The 21-meter-long drive (about 69 feet) at the end of this plan will maneuver the rover past the sandy ramp to the top of the main boxwork region. From here, the science team will be able to explore this fascinating area of particularly large boxwork structures. Stay tuned as Curiosity continues to climb higher and delve deeper into the geologic history of Mars!

      For more Curiosity blog posts, visit MSL Mission Updates


      Learn more about Curiosity’s science instruments

      Share








      Details
      Last Updated Jul 16, 2025 Related Terms
      Blogs Explore More
      2 min read Curiosity Blog, Sols 4597-4599: Wide Open Spaces


      Article


      1 hour ago
      3 min read Curiosity Blog, Sols 4595-4596: Just Another Beautiful Day on Mars


      Article


      23 hours ago
      4 min read Curiosity Blog, Sols 4593-4594: Three Layers and a Lot of Structure at Volcán Peña Blanca


      Article


      5 days ago
      Keep Exploring Discover More Topics From NASA
      Mars


      Mars is the fourth planet from the Sun, and the seventh largest. It’s the only planet we know of inhabited…


      All Mars Resources


      Explore this collection of Mars images, videos, resources, PDFs, and toolkits. Discover valuable content designed to inform, educate, and inspire,…


      Rover Basics


      Each robotic explorer sent to the Red Planet has its own unique capabilities driven by science. Many attributes of a…


      Mars Exploration: Science Goals


      The key to understanding the past, present or future potential for life on Mars can be found in NASA’s four…

      View the full article
    • By NASA
      In northwest Australia, the Great Sandy Desert holds great geological interest as a zone of active sand dune movement. While a variety of dune forms appear across the region, this astronaut photograph features numerous linear dunes (about 25 meters high) separated in a roughly regular fashion (0.5 to 1.5 kilometers apart).NASA On March 25, 2013, an astronaut aboard the International Space Station took this photo of the Great Sandy Desert in northwest Australia, showcasing linear dunes separated in a roughly regular fashion. When you fly over such dune fields—either in an airplane or the space station—the fire scars stand out. Where thin vegetation has been burned, the dunes appear red from the underlying sand; dunes appear darker where the vegetation remains.
      Strings of narrow lakes that represent ancient rivers are also present in the region. The white feature down the center of the image is Lake Auld. The color is the result of a cemented combination of fine, clay-like sediment and salts from the evaporation of flood waters that occasionally fill the lake. Linear dunes can be seen entering Lake Auld on the east side. During flooding events, the sand of the dune noses is dispersed, becoming incorporated into the muds and salts of the lake floor sediments. During the long, intervening dry periods, sand can blow across the lake floor to build thinner, smaller dunes, visible as linear accumulations on the west side of the lake.
      See more photos taken by astronauts.
      Text credit: NASA/M. Justin Wilkinson
      Image credit: NASA
      View the full article
    • By NASA
      Curiosity Navigation Curiosity Home Mission Overview Where is Curiosity? Mission Updates Science Overview Instruments Highlights Exploration Goals News and Features Multimedia Curiosity Raw Images Images Videos Audio Mosaics More Resources Mars Missions Mars Sample Return Mars Perseverance Rover Mars Curiosity Rover MAVEN Mars Reconnaissance Orbiter Mars Odyssey More Mars Missions Mars Home 3 min read
      Sols 4500-4501: Bedrock With a Side of Sand
      NASA’s Mars rover Curiosity acquired this image using its Left Navigation Camera on March 28, 2025 — Sol 4494, or Martian day 4,494 of the Mars Science Laboratory mission — at 17:06:34 UTC. NASA/JPL-Caltech Written by Sharon Wilson Purdy, Planetary Geologist at Smithsonian National Air and Space Museum
      Earth planning date: Wednesday, April 2, 2025
      Wow, sol 4500. What an impressive number of sols (Martian days) exploring the Red Planet! This delightfully even sol number made me wonder where the Mars Exploration Rover (MER) Opportunity was at this point in her mission (Opportunity’s twin rover, Spirit, explored Gusev crater on Mars for roughly 2210 sols). As it turns out, Opportunity was driving over fairly smooth terrain on sol 4500 and was approaching a light-toned rounded hill named “Spirit Mound” on the western rim of Endeavour crater in Meridiani Planum. 
      I am always so impressed and proud when I stop to think about the incredible fleet of rovers we have safely landed and operated on Mars, and the amazing scientific discoveries that have resulted from these missions!
      Today I served on science operations as the “keeper of the plan” for the geology and mineralogy theme group. In this role, I assembled the activities in our team planning software for this two-sol plan. Our small plan becomes part of a much larger set of instructions that will be relayed up to the rover later today. Currently, the Curiosity rover is driving up Mount Sharp over broken-up blocks of bedrock and sand through a small canyon en route to the boxwork structures ahead. This bumpy terrain can sometimes make it hard to pass the “Slip Risk Assessment Process” (SRAP) where all six wheels are required to be stable on the ground before we can unstow our robotic arm to use the contact science instruments. After our successful 8-meter drive (about 26 feet) from yestersol we passed SRAP and got to work selecting targets for contact and remote observations.
      The team chose to characterize a bedrock target in front of us called “Chuckwalla” using the dust removal tool (DRT), APXS, and MAHLI.  ChemCam used its LIBS instrument to analyze the chemistry of a nearby bedrock target with a knobby texture, “Pechacho,” and took a long distance RMI image to study the interesting layering in the “Devil’s Gate” butte. Mastcam assembled an impressive portfolio of observations in this two-sol plan. The team imaged variations in bedrock textures at “Jalama” and “Julian” and documented the nature of the “Mishe Mokwa” ridgeline. In addition, Mastcam imaged darker rocks within a previously acquired mosaic of Devil’s Gate and investigated narrow troughs (small depressions) within the sand in the workspace.
      The environmental theme group, with their eye on the sky, included activities to measure the optical depth of the atmosphere, constrain aerosol scattering properties, and observe clouds. A very busy day of planning for sols 4500-4501, with many more to come!
      Share








      Details
      Last Updated Apr 07, 2025 Related Terms
      Blogs Explore More
      3 min read Sols 4498-4499: Flexing Our Arm Once Again


      Article


      4 days ago
      2 min read Sols 4495-4497: Yawn, Perched, and Rollin’


      Article


      7 days ago
      3 min read Visiting Mars on the Way to the Outer Solar System


      Article


      1 week ago
      Keep Exploring Discover More Topics From NASA
      Mars


      Mars is the fourth planet from the Sun, and the seventh largest. It’s the only planet we know of inhabited…


      All Mars Resources


      Explore this collection of Mars images, videos, resources, PDFs, and toolkits. Discover valuable content designed to inform, educate, and inspire,…


      Rover Basics


      Each robotic explorer sent to the Red Planet has its own unique capabilities driven by science. Many attributes of a…


      Mars Exploration: Science Goals


      The key to understanding the past, present or future potential for life on Mars can be found in NASA’s four…

      View the full article
    • By USH
      On December 25, 2024, NASA's Stereo Lasco C3 satellite captured an extraordinary phenomenon near the sun. In a split second, the satellite's imaging was disrupted by what appeared to be a swarm of spherical objects hurtling through space at incredible speeds. 

      Speculation surrounds the event, with some suggesting it could be a meteor debris field. However, the unusual appearance of the objects has raised questions. Could debris naturally form into such perfectly round shapes, each featuring a dark center that resembles donut-shaped UFOs? 

      This event might be a natural occurrence, however, with all the recent strange sightings of unknown drones, UFOs, and orbs combined with predictions from several specialists that something significant might happen soon in the realm of the UFO phenomena, one might wonder if these mysterious spheres are connected to something larger on the horizon?


      View the full article
    • By NASA
      Curiosity Navigation Curiosity Home Mission Overview Where is Curiosity? Mission Updates Science Overview Instruments Highlights Exploration Goals News and Features Multimedia Curiosity Raw Images Images Videos Audio More Resources Mars Missions Mars Sample Return Mars Perseverance Rover Mars Curiosity Rover MAVEN Mars Reconnaissance Orbiter Mars Odyssey More Mars Missions The Solar System The Sun Mercury Venus Earth The Moon Mars Jupiter Saturn Uranus Neptune Pluto & Dwarf Planets Asteroids, Comets & Meteors The Kuiper Belt The Oort Cloud 3 min read
      Sols 4325-4326: (Not Quite) Dipping Our Toes in the Sand
      NASA’s Mars rover Curiosity captured this image using its Left Navigation Camera on Sol 4323 — Martian day 4,323 of the Mars Science Laboratory mission — on Oct. 4, 2024, at 00:29:40 UTC. NASA/JPL-Caltech Earth planning date: Friday, Oct. 4, 2024
      If you read this blog very often, you know that nearly every time the rover stops for science, MAHLI and APXS focus on interesting (and accessible!) rocks as targets. The rover science team is, after all, built with a lot of geologists. But geology is not all rocks, all the time — sand is former rock that if buried and pressurized long enough will become rock again. Today was time for sand to shine, as the workspace was cut by troughs of sand of different colors and brightnesses, and it had been nearly 500 sols since we acquired our last dedicated sand measurement with APXS and MAHLI. The “Pumice Flat” target was one of the brighter sand patches while “Kidney Lake” was one of the darker sand patches. APXS uses a special placement mode over sand targets so the instrument gets close, but not too close, to the loose material which could foul up the instrument. Not-rock was also the purview of our environmental observations. Navcam is scheduled for imaging seeking out clouds and dust devils, and changes in the sand and dust on top of the rover deck. Both Navcam and Mastcam will make observations to measure the amount of dust in the atmosphere. REMS will keep track of our weather with regular measurements, RAD will monitor our radiation environment, and DAN will look through rock for signs of water beneath our drive path.
      Unsurprisingly, the rest of the rover could not ignore bedrock. We managed to squeeze in DRT cleaning of a nice bedrock slab, “Ribbon Fall,” for MAHLI-only imaging. In places, the bedrock slabs were cut by thin veins of darker gray material, similar to dark gray materials we saw in the bedrock on the other side of Gediz Vallis. ChemCam targeted one of these dark gray examples at “Black Divide,” and also rastered across some of the prominent layers visible in the vertical faces in the workspace at the aptly named “Profile View.” 
      Our imaging efforts could be roughly divided between looking back at our path through Gediz Vallis from our new and higher perspective, and looking ahead to what awaits us. ChemCam planned RMI mosaics back toward a field of the white stones we spent time studying in Gediz Vallis and toward a part of the edge of Gediz Vallis that we did not explore previously. Mastcam looked back at the part of the edge of Gediz Vallis we just traversed, “Pilot Peak,” for clues as to why it sits higher than the bedrock farther from the channel edge. They also targeted “Clyde Spires,” which was a gravel ridge in Gediz Vallis of interest as we drove by it initially. Looking ahead, Mastcam imaged a puzzling gray rock sitting atop the bedrock slabs south of us at target “Buena Vista Grove,” and further south still, they planned a large mosaic covering a very big rock — the spectacular “Texoli” butte that has loomed and will continue to loom over our path for months to come.
      Written by Michelle Minitti, Planetary Geologist at Framework
      Share








      Details
      Last Updated Oct 07, 2024 Related Terms
      Blogs Explore More
      2 min read Perseverance Matters
      It is an important and exciting juncture in Mars exploration and astrobiology. This year, the…


      Article


      5 hours ago
      2 min read Sols 4323-4324: Surfin’ Our Way out of the Channel


      Article


      4 days ago
      2 min read Sols 4321-4322: Sailing Out of Gediz Vallis


      Article


      5 days ago
      Keep Exploring Discover More Topics From NASA
      Mars


      Mars is the fourth planet from the Sun, and the seventh largest. It’s the only planet we know of inhabited…


      All Mars Resources


      Explore this collection of Mars images, videos, resources, PDFs, and toolkits. Discover valuable content designed to inform, educate, and inspire,…


      Rover Basics


      Each robotic explorer sent to the Red Planet has its own unique capabilities driven by science. Many attributes of a…


      Mars Exploration: Science Goals


      The key to understanding the past, present or future potential for life on Mars can be found in NASA’s four…

      View the full article
  • Check out these Videos

×
×
  • Create New...