Curiosity Blog, Sols 4838-4844: Wrapping Up the Boxwork Terrain
Written by Deborah Padgett, MSL Operations Product Ground System Project Manager at NASA’s Jet Propulsion Laboratory
Date of earthworks: Friday March 20, 2026
Curiosity has just concluded a very intense week of scientific observations and engineering activities, as it wraps up its month-long investigation of the Martian box terrain. Three days of planning this week by the MSL science and engineering team led to three rover moves, three sets of targets for detailed study by the instruments on Curiosity’s arm, and a vast array of in situ data characterizing the southern portion of the box terrain on the shoulder of Mount Sharp on Mars.
As the week began on the soil of Mars 4838, Curiosity used cameras on Mastcam and ChemCam to image the ridge and mound targets “Salar de Maricunga”, “El Misti”, the “Saipina” ridges and the “Paniri” mound. Mastcam also examined bedrock fractures at the “Sajta” target. The ChemCam laser spectrometer examined the composition of the “Tacitas” target. After sweeping a large part of the dust from the rock target “Toro Wharku” with the DRT, MAHLI and APXS studied it in detail. MAHLI also carried out detailed imaging of the neighboring rim “Rincodillas”. In the afternoon, line-of-sight observations from Mastcam Tau and Navcam measured the amount of dust in the Martian atmosphere.
On sol 4839, Curiosity completed its investigation of Toro Wharku with ChemCam laser spectroscopy and Mastcam imaging. A long distance ChemCam RMI 10×1 mosaic was obtained on Paniri Butte, and Navcam filmed clouds and dust. The rover then traveled 35 meters (about 115 feet) toward the southern contact of the box terrain with the adjacent sulfate unit, and performed post-trip photography of a 360-degree panorama around the vehicle using Navcam.
On Sol 4840, these images made it possible to select a uniquely shaped rock formation called “Llisa” for a study by laser spectrometer with ChemCam and Mastcam. Although no accessible bedrock is smooth enough for DRT brushing, MAHLI obtained microscopic images of “Chusumayo” and the APXS target “Sierra Gorda”, in bedrock showing very intriguing sedimentary layers. Mastcam also photographed these layers on the “Limbaba” and “Limbaba2” targets. The ChemCam telescope’s RMI camera looked along Curiosity’s path to the now-distant Mishe Mokwa Butte, observing its stratigraphy from a different angle. Atmospheric studies included a Mastcam sky survey, Mastcam tau, and a Navcam Dust-Devil film. The next sol, 4841, concluded the Chusumayo study with ChemCam LIBS observations of the nearby target “La Troya”.
On Sol 4841, Curiosity traveled 39 meters (about 128 feet) farther south. In Friday’s plan for soils 4842 to 4844, the soil begins with ChemCam laser spectrometer composition and Mastcam imaging studies of the “San Julien” outcrop, followed by telescopic RMI images of the “Santa Rita” dark ridge material. Mastcam will then obtain a series of mosaics documenting the southern contact between the box structures and the sulfate unit, from nearby bedrock to the more distant hillsides of Paniri Butte. Mastcam imagery will also investigate the possibility of regolith movement in a trough. A film of clouds above the horizon, a film of the dust devil, and line-of-sight dust observations with Navcam will integrate atmospheric investigations into the morning science block. Curiosity will then unblock the arm, performing DRT brushing, MAHLI imaging and APXS measurement on the “Challapata” target. Another Navcam line of sight and a tau Mastcam will complement the atmospheric dust measurements for the ground.
The next sol, 4843, will see ChemCam laser spectroscopy and Mastcam imaging of the dark ridge target “Santa Laura”. Mastcam will then obtain additional mosaics of the southern contact (“Yungas de Arepucho”), as well as a “Limbaba lookback” target. ChemCam’s RMI telescope will image the upper reaches of the Paniri Butte, complementing Mastcam coverage. Morning and evening surveys by Navcam and Mastcam will continue the time series of dust and dynamics in the Martian atmosphere, accompanied by a nighttime APXS atmospheric observation.
On the morning of sol 4844, ChemCam will complete the study of Challapata by laser spectroscopy, and Mastcam will document changes in the target after its zapping. After a passive ChemCam sky observation and a Navcam survey of the dust devils, Curiosity will travel another 11 meters south (36 feet), most likely crossing the long-awaited boundary between the Martian box structures and the sulfate unit beyond. During the ride, MAHLI will perform a full set of wheel imaging to track wear on the rover’s wheels. In concert with post-training imaging, ChemCam and Navcam will perform an AEGIS survey, allowing onboard Navcam data processing to choose a ChemCam LIBS target before our human team sees the images. The plan concludes on the morning of sol 4845 with ChemCam laser spectroscopy of this new AEGIS target, in addition to atmospheric studies with Navcam and Mastcam.
Next week, Curiosity will leave the Martian terrain to embark on its quest for new discoveries.
