Cloudy Sols Are Here Again
Mars Perseverance Sol 691 - Left Navigation Camera: This image was taken just before sunrise, pointing east. NASA's Mars Perseverance rover acquired this image using its onboard Left Navigation Camera (Navcam). The camera is located high on the rover's mast and aids in driving. This image was acquired on Jan. 29, 2023 (Sol 691) at the local mean solar time of 06:14:49. Credits: NASA/JPL-Caltech. Download image ›

Mars clouds are very much like Earth’s cirrus clouds but thinner. While Earth clouds can contain liquid water, the low temperatures and pressures on Mars only allow for water-ice (and CO2 ice) clouds to form. However, these water-ice clouds are optically thin because of the low amounts of water present in the Martian atmosphere; if all the water were on the surface, it would make a layer thinner than a single strand of hair.

Studying clouds helps us to understand the atmosphere and how the water cycle works on Mars today, such as how water vapor is transported by the atmospheric circulation and how temperatures and water abundances vary with height. By observing the motion of clouds, we can also learn about wind speeds and directions high in the atmosphere, which we have no way of measuring otherwise. Despite being thin, these clouds still have an impact on heating and cooling of the present day atmosphere, and in the past clouds may have played a much larger role in sustaining a warmer atmosphere that allowed liquid water to flow on the surface of Mars.

There are seasonal patterns to Martian clouds. For a few months around northern summer solstice, orbital spacecraft observe a lot of cloud activity between ~10° south and 30° north latitude. Because Perseverance is exploring Jezero crater, which is located at about 18° north, we’re in a great place to observe these clouds from the surface! We’re currently over a month before the nominal start of this cloudy season, but are already starting to see more cloud activity. The image shown was taken by the rover’s Navigation camera (Navcam) on sol 691 of the mission, shortly before sunrise looking to the east, and shows thin cloud layers illuminated by the rising Sun.

We regularly take Navcam images and movies to study the timing, motion, and morphology of clouds above Jezero crater. When there are lots of clouds around, we also take Mastcam-Z images (which contain more spectral information) to learn more about the makeup of these clouds, such as the average particle size. We also monitor clouds using Mars Environmental Dynamics Analyzer (MEDA) sensors. MEDA’s Radiation and Dust Sensor (RDS) measures incoming solar radiation at different wavelengths and can detect when clouds are blocking or scattering some of the sunlight reaching the sensors. MEDA’s Thermal Infrared Sensor (TIRS) measures thermal radiation from the sky and from the surface and can also provide information on clouds. For example, if clouds are present around sunset, the surface temperature falls more slowly than usual after the Sun goes down, because even these thin clouds emit enough downward thermal radiation to continue warming the surface. Finally, MEDA’s upward-pointing Skycam camera takes images looking for clouds on a daily basis.

We expect it to get increasingly cloudy as we approach and enter the cloudy season, so we will be on the lookout for interesting cloud activity in our observations. Near the end of last year’s cloudy season, we saw something that had never previously been found beyond Earth: a halo around the Sun, which lasted for several hours. Halos are caused by light being refracted and reflected by big ice crystals, which can form only when there is a large enough concentration of water vapor. We’ll certainly be watching for halos again when we reach the same time this Mars years, which will be around the end of October.

About This Blog

These blog updates are provided by self-selected Mars 2020 mission team members who love to share what Perseverance is doing with the public.

Dates of planned rover activities described in these blogs are subject to change due to a variety of factors related to the Martian environment, communication relays and rover status.

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  • Mariah Baker
    Planetary Scientist, Smithsonian National Air & Space Museum
    Washington, DC
  • Matthew Brand
    SuperCam/ChemCam Engineer, Los Alamos National LaboratoryLos Alamos National Laboratory
  • Sawyer Brooks
    Docking Systems Engineer, NASA/JPL
    Pasadena, CA
  • Adrian Brown
    Deputy Program Scientist, NASA HQ
    Washington, DC
  • Denise Buckner
    Student Collaborator, University of Florida
    Gainesville, FL
  • Fred Calef III
    Mapping Specialist, NASA/JPL
    Pasadena, CA
  • Stephanie Connell
    SuperCam, PhD Student, Purdue University
    West Lafayette, IN
  • Alyssa Deardorff
    Systems Engineer, NASA/JPL
    Pasadena, CA
  • Kenneth Farley
    Project Scientist, Caltech
    Pasadena, CA
  • Phylindia Gant
    Mars 2020 Student Collaborator, University of Florida
    Gainesville, FL
  • Brad Garczynski
    Student Collaborator, Purdue University
    West Lafayette, IN
  • Erin Gibbons
    Student Collaborator, McGill University
    Montreal, Canada
  • Michael Hecht
    Mars Oxygen In-Situ Resource Utilization Experiment (MOXIE) Principal Investigator, Massachusetts Institute of Technology
    Westford, MA
  • Louise Jandura
    Chief Engineer for Sampling & Caching, NASA/JPL
    Pasadena, CA
  • Elisha Jhoti
    Ph.D. Student, University of California, Los Angeles
    Los Angeles, CA
  • Bavani Kathir
    Student Collaborator on Mastcam-Z, Western Washington University
  • Lydia Kivrak
    Student Collaborator, University of Florida
    Gainesville, FL
  • Rachel Kronyak
    Systems Engineer, NASA/JPL
    Pasadena, CA
  • Steven Lee
    Perseverance Deputy Project Manager, NASA/JPL
    Pasadena, CA
  • An Li
    Student Collaborator on PIXL, University of Washington
  • Justin Maki
    Imaging Scientist and Mastcam-Z Deputy Principal Investigator, NASA/JPL
  • Forrest Meyen
    MOXIE Science Team Member, Lunar Outpost
  • Sarah Milkovich
    Assistant Science Manager, NASA/JPL
    Pasadena, CA
  • Eleanor Moreland
    Ph.D. Student, Rice University
    Houston, Texas
  • Matt Muszynski
    Vehicle Systems Engineer, NASA/JPL
    Pasadena, CA
  • Claire Newman
    Atmospheric Scientist, Aeolis Research
    Altadena, CA
  • Avi Okon
    Sampling Operations Deputy Lead, NASA/JPL
    Pasadena, CA
  • Pegah Pashai
    Vehicle Systems Engineer Lead, NASA/JPL
    Pasadena, CA
  • David Pedersen
    Co-Investigator, PIXL Instrument, Technical University of Denmark (DTU)
    Copenhagen, Denmark
  • Eleni Ravanis
    Student Collaborator, University of Hawaiʻi at Mānoa
    Honolulu, HI
  • Thirupathi Srinivasan
    Robotic Systems Engineer, NASA/JPL
  • Kathryn Stack
    Deputy Project Scientist, NASA/JPL
    Pasadena, CA
  • Vivian Sun
    Science Operations Systems Engineer, Staff Scientist, NASA/JPL
    Pasadena, CA
  • Iona (Brockie) Tirona
    Sampling Engineer, NASA/JPL
    Pasadena, CA
  • Jennifer Trosper
    Project Manager, NASA/JPL
    Pasadena, CA
  • Vandi Verma
    Chief Engineer for Robotic Operations, NASA/JPL
    Pasadena, CA
  • Rick Welch
    Deputy Project Manager, NASA/JPL
    Pasadena, CA
  • Roger Wiens
    Principal Investigator, SuperCam / Co-Investigator, SHERLOC instrument, Purdue University
    West Lafayette, IN

Tools on the Perseverance Rover+

The Perseverance rover has tools to study the history of its landing site, seek signs of ancient life, collect rock and soil samples, and help prepare for human exploration of Mars. The rover carries:


Where is the Rover?

Image of a rover pin-point at Perseverance's location on Mars, Jezero Crater

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