I am always so proud when NASA achieves. I certainly have a bias because of spending twelve years of my career as a research meteorologist at NASA Goddard Space Flight Center. It was one of the most rewarding experiences of my life. I even made it through questions like, “Do you forecast for shuttle launches?” or “Do you know any astronauts?” NASA’s mission includes far more than the human spaceflight but that is only what many people associate with the agency. While my work was related to the Earth Science Division, this past week NASA achieved another spectacular achievement in planetary exploration by landing Perseverance on Mars. Some of you may be wondering, “So what’s the weather like there?”
A good place to answer that question is by following Mars Weather on Twitter. Though not an official NASA site, it provides updates from weather instruments aboard the Mars Curiosity and NASA Insight platforms. Curiosity is a rover on Mars that carries the Rover Environmental Monitoring Station (REMS). According to the NASA JPL website, “Curiosity is taking daily weather measurements at Gale Crater in the southern hemisphere of Mars, near the equator.”
At that location, it is currently early autumn. The weather reported on February 18th at that location is shown above. On Sol 3035, the high temperature was 18 degrees F, and the low temperature was -101 degrees F. If you look at the previous days, this was actually the warmest day of the week. By the way, a “sol” is a Martian day (24 hours, 39 minutes, 35 seconds), and it is a bit longer than our day One year on Mars is roughly 668 sols.
The Mars Insight lander is at Elysium Planitia and can also provide weather information, however, the NASA website recently posted that, “InSight has temporarily suspended daily weather measurements. As more data becomes available, it will appear below.” The Insight website does have a really interesting plot of seasonal weather data (see above) at the location near the Martian equator. Air temperature does not vary wildly, and it doesn’t near our Equator either. The seasonal cycle is very evident in pressure, wind direction, and atmospheric opacity, which is a measurement of how much sunlight is blocked by Martian dust. By the way, NASA recently released amazing audio from the Perseverance mission with a gentle breeze in the background.
There are other fascinating aspects of Martian weather. The U.S. just experienced a crippling cold blast because of a weakened Polar Vortex. Mars has a Polar Vortex too. I have described it previously in Forbes. Check out the rather festive NASA assessment of the role of the Martian Polar Vortex on the 2001 Mars Odyssey spacecraft. It even mentions Santa.
While Polar Vortex features are actually common on planetary bodies of our solar system, Mars also has smaller vortex features. Martian dust tornadoes or “dust devils” can disrupt solar energy to rovers, but they can also clean their solar panels too. Like thunderstorms on Earth, sunlight warming the surface can destabilize the air and cause rising motion. NASA’s website points out that, “Rising plumes of warm air create everything from small dust devils, similar to those that form in deserts on Earth, to larger continent-sized storms.” Like Earth, the aforementioned seasonal cycle on Mars is caused by the axial tilt as the planet orbits the Sun. Mars has a less circular orbit than Earth so its Southern Hemisphere is closer to the Sun in summer, which means larger dust storms then.
The Perseverance mission is designed to pave the way for human exploration of Mars by assessing the geology and past climate of the planet. Lisa May is Chief Technologist for Lockheed Martin Commercial Civil Space Advanced Programs and a veteran of the NASA Mars program. She told me, “After decades of planning, there will finally be pristine samples scientists can analyze in labs back on Earth.” This matters because Mars rocks have not been altered as much by weather and may hold secrets about the early solar system and Earth. The mission also carries the Mars helicopter Ingenuity, which is a technology demonstration to evaluate powered flight on Mars. As a meteorologist, I will be watching this part of the mission very closely because things that fly usually are affected by weather. May went on to say, “the Mars helicopter design, like the complex Perseverance landing system, accommodates for the thin atmosphere on Mars (<1% of Earth’s).”