Sols 4416-4417: New Year, New Clouds

NASA’s Mars rover Curiosity captured this image of noctilucent clouds using its Right Navigation Camera on sol 4401 — or Martian day 4,401 of the Mars Science Laboratory mission — on Dec. 23, 2024, at 08:57:15 UTC.

NASA/JPL-Caltech

Earth planning date: Monday, Jan. 6, 2025

After our marathon holiday plan, we’re easing back into the new year with a standard two-sol plan. We did arrive today to the news that the drive hadn’t made it as far as we wanted, but luckily the rover planners determined that we were still in a good position to do contact science on two wintry targets — “Snow Creek” and “Winter Creek.” We also packed in lots of remote science with ChemCam using LIBS on “Grapevine” and “Skull Rock,” and we are doing long-distance imaging of the Texoli and Wilkerson buttes, and Gould Mesa. Mastcam will be imaging a number of targets near and far as well including “Red Box”’ “Point Mugu,” “Stone Canyon,” “Pine Cove,” and “Hummingbird Sage,” which will examine various structures in the bedrock. We can’t forget about the atmosphere either — we have a couple dust-devil surveys to look for dust lifting, but the real star of the show (at least for me) is the cloud imaging.

While we’re just into 2025 here on Earth, we’re also near the start of a new year on Mars! A Mars year starts at the northern vernal equinox (or the start of autumn in the southern hemisphere, where Curiosity is), and Mars year 38 started on Nov. 12.

We’re about a third of the way through autumn on Mars now, and the southern Martian autumn and winter bring one thing — clouds! Near the start of the Martian year we start seeing clouds around sunset. These are noctilucent (meaning “night illuminated”) clouds. Even though the sun has set in Gale Crater, the clouds are high enough in the atmosphere that the sun still shines on them, making them seem to almost glow in the sky. You can see this with clouds on Earth, too, around twilight! Mars year 38 will be our fourth year capturing these twilight clouds, and the Navcam images (one of which you can see above) already show it’s shaping up to be another year of spectacular clouds!

Written by Alex Innanen, Atmospheric Scientist at York University