With Curiosity parked, videos from the rover show its shadow moving across the Martian surface during a 12-hour sequence.
when NASAinterest in tuesday While the rover is not in motion, it works well as a sundial, as seen in two black-and-white videos recorded on Nov. 8, the 4,002nd Martian day, or sol. The rover used its black-and-white hazard-avoidance cameras, or Hascams, to capture its own shadow on the Martian surface.
The instructions for recording the videos were part of the last set of instructions issued to Curiosity just before the start of Mars' solar conjunction, the period when the Sun is between Earth and Mars. Because Plasma Radio communications from the Sun can be interfered with, during which operations to transmit commands to the Mars spacecraft are halted for several weeks. (The expeditions were completely unrelated: they regularly radioed back routine health checks.)
NASA's Curiosity rover captured 12 hours of the Martian day using its front and rear black-and-white HASCAMs during a two-week standstill on Mars during its solar conjunction in November 2023. The shadow of the rover can be seen on the surface in these images taken by the pre-Hazcam. Credit: NASA/JPL-Caltech
Rover drivers typically rely on Curiosity's Hascams to spot rocks, slopes and other hazards. But with the rover's other operations deliberately curtailed just before docking, the team decided to use Hascams to record 12-hour snapshots for the first time, hoping to catch clouds or dust devils that might reveal more about the Red Planet's weather.
When the images arrived back on Earth after merging, scientists didn't see any weather, but a pair of 25-frame videos they stitched together capture the passage of time. The videos, which span from 5:30 a.m. to 5:30 p.m. local time, show Curiosity's shadow changing as the day moves from morning to afternoon.
The first video features images from the front of Haskam, which looks southeast over the Gediz Vallis, a valley found on Mount Sharp. Curiosity has been climbing the base of the 3-mile (5-kilometer-high) mountain that sits in Gale Crater since 2014.
As the sky brightens at sunrise, the shadow of the rover's 7-foot (2-meter) robotic arm moves to the left, and Curiosity's front wheels emerge from the darkness on either side of the frame. A circular calibration target mounted on the shoulder of the robotic arm is visible on the left. Engineers use it to test the target Accuracy of Alpha particle X-ray spectrometerAn instrument that detects chemical elements on the surface of Mars.
By mid-day, the front Hazcam's auto-exposure algorithm settles exposure times to a third of a second. At night, that exposure time grows by more than a minute, causing typical sensor noise known as „hot pixels” to appear as white snow across the final image.
In this 12-hour view looking toward the floor of Gale Crater, Curiosity's rear Huscam captures the shadow of the rover's rear. A number of image artifacts were caused by a variety of factors, including a black spot, a distorted appearance of the Sun, and rows of white pixels emanating from the Sun. Credit: NASA/JPL-Caltech
The second video shows a view of the rear Haskam from the slopes of Mount Sharp looking northwest to the floor of Gale Crater. The rover's right rear wheel is visible along with Curiosity's shadow power system. During the 17th frame, a small black artifact appears in the middle left of the video. Cosmic Ray Hitting the camera sensor. Likewise, the bright flashes and other noise at the end of the video are a result of heat from the spacecraft's power system affecting Hascom's image sensor.
These images have been re-projected to accommodate the Hascams' wide-angle lenses. 11 years of Martian dust has settled on the lenses, giving the images a speckled appearance, especially in rear-facing camera video.
More about the mission
Curiosity was built by NASA's Jet Propulsion Laboratory, which is managed by Caltech in Pasadena, California. JPL is leading the mission on behalf of NASA's Science Operations Directorate in Washington.