# Curiosity Rover Observes Seasonal Cloud Formations on Mars The Mars Science Laboratory mission enters a new year while documenting atmospheric changes. - **Source:** [NASA](https://www.nasa.gov) - **Published:** 2026-10-20 - **Topic:** [Business](https://brifing.si/c/business) - **Original article:** - **On Brifing:** https://brifing.si/s/d99c4821-216b-4a73-a136-8311467dbb2d ## Mission Milestone Reached The Curiosity rover mission reached Sol 5037 on October 7, 2026, marking a significant operational milestone. The team recently celebrated the start of Martian Year 39, which coincides with the vernal equinox in the northern hemisphere. This transition signals the beginning of autumn for the rover located in Gale Crater. ## Drilling Operations Concluded Recent weeks focused on the Basque Lakes drill campaign, which concluded following extensive laboratory analysis. The SAM team performed an additional Gas Chromatograph/Mass Spectrometry experiment to maximize scientific output. Despite the high energy demands of GCMS, the team successfully integrated remote-sensing activities from Mastcam and ChemCam into the four-sol plan. ## Analyzing Drill Tailings Before departing the Basque Lakes site, the team prioritized contact science on the drill tailings. These leftover rock and mineral fragments provide critical data regarding the local geology. Researchers utilized the remaining time to finalize these observations, ensuring all potential scientific targets were captured before the rover initiates its next drive. ## Upcoming Navigation Objectives The mission plan now shifts toward a drive back to the Chiu Chiu region. Scientists are particularly interested in returning to this area to further investigate unique crystal forms identified during previous traverses. This movement represents a strategic shift from intensive drilling operations back to regional exploration and geological site assessment. ## Atmospheric Seasonal Changes As autumn progresses in Gale Crater, the atmosphere undergoes distinct seasonal shifts. The team is specifically monitoring the return of high-altitude twilight clouds. These formations become visible due to the low sun angle at sunset, which illuminates the clouds against the darkening sky, providing a unique opportunity for atmospheric data collection. ## Imaging Twilight Clouds Curiosity captured its first high-altitude clouds of the season during late afternoon movies on Wednesday. While most clouds in Gale Crater remain suboptical and invisible to robotic sensors, these twilight formations are bright enough for the Right Navigation Camera to detect. These images confirm the onset of the expected seasonal cloud patterns. ## Scientific Instrument Utility The mission relies on a suite of instruments, including the Navcam and ChemCam, to document these environmental phenomena. By leveraging the rover's mobility and sensor capabilities, the team tracks how solar longitude influences Martian weather. This ongoing observation cycle is essential for understanding the complex atmospheric dynamics present on the planet. ## Long-term Mission Significance Monitoring these atmospheric cycles over multiple Martian years allows scientists to build a comprehensive dataset of seasonal variability. By correlating cloud activity with solar longitude, the mission team refines its understanding of the Martian climate. These observations remain a cornerstone of the broader Mars Science Laboratory mission goals for planetary exploration. ## Sources covering this story - https://science.nasa.gov/blog/curiosity-blog-sols-5036-5042-watching-the-clouds-go-by/ — --- _Summary written by Brifing from the original reporting. Copyright in the original article belongs to its publisher; read the full piece at the link above._