Mars Rover Prepares to Drill Rock Studded With Strange Discs and Needles

NASA’s Curiosity rover is getting ready to drill into a new rock on Mars, a target the science team has named Nazca. The rock is covered in lumps shaped like discs and needles, a texture that scientists hope will reveal how the rock formed, according to a mission blog post by planetary scientist Lucy Lim of NASA’s Goddard Space Flight Center.

The post describes planning work for Oct. 16, 2026, after Curiosity finished its earlier Basque Lakes drill campaign. The rover has now returned to a spot a few meters from a block called Chiu Chiu, where the next drilling effort will take place.

Why did Curiosity move to Nazca?

Chiu Chiu itself turned out to be a poor candidate for drilling, but the block just beyond it looked more promising, so the team made it the rover’s driving target. Close-up images taken after the drive showed that this neighboring block was crowded with the same disc- and needle-shaped lumps seen on Chiu Chiu. The team quickly approved preparations for drilling and gave the spot its new name.

What are the discs and needles?

One leading hypothesis is that the shapes first appeared as crystals grew. Minerals tend to form particular shapes depending on their microscopic structure, much like the salt crystals many people grow at home as a school science project.

The fairly large size of these features at Nazca and Chiu Chiu offers clues about the temperature when they grew and how much salt and fluid was available. There is a catch, though. The rock’s present-day makeup may not match the original mineral, because crystals can later be swapped for different minerals. The replacements are called pseudomorphs: they keep the shape of the first mineral but not its composition or molecular structure.

What will the rover do before it drills?

Ahead of the drill preload test, the team planned several special observations to study the crystal shapes in fine detail.

• The MAHLI camera will take a Quantitative Relief Model observation made of five overlapping images at slightly different angles, which can be combined into a detailed 3D model of the surface.
• MAHLI will also add extra frames to its sharpest imaging by doubling the number of focus steps, which should increase the resolution of those 3D models.
• The ChemCam laser instrument will run a depth profile on a nearby target called Toucan, which is also rich in crystal forms. Normally the 150 laser shots in a day’s observation are spread over five points, with 30 shots at each. This time all 150 will hit one spot.
• The LIBS, DRT and APXS instruments will examine the Nazca surface before the preload test, so the team knows its surface composition as thoroughly as possible before drilling.

Each laser shot vaporizes a tiny amount of rock into a plasma. According to the post, the 150-shot profile should reach about five times deeper than a normal 30-shot observation, letting scientists check whether the inside of a crystal form differs from its surface.

Why does it matter?

Whether the inside matches the outside could say something about two things: how the surface has been affected by today’s Martian environment, and the conditions in which the crystal form first developed. Lim called it an experiment worth pursuing. The results will help the team judge what these odd textures are before the drill goes in, and the drilled sample should give a fuller picture of the rock.

The third LIBS observation in the plan is aimed at a nearby block named Condor, where a finely layered texture is exposed.

Is Curiosity studying anything else?

Yes. As twilight cloud season begins, the rover also kept watching the modern Martian atmosphere. The plan includes nighttime images of Phobos, the larger and brighter of Mars’ two moons. When Phobos is full, sunlight reflecting off the moon and scattering in the atmosphere can help estimate the particle sizes in clouds. Solar observations can do something similar, but the Phobos images let scientists measure cloud particles later in the night. The team expects this observation to capture high-altitude clouds of carbon dioxide.

Around Prague, based on reporting by NASA