One aspect of putting humans on Mars is often overlooked. Weather. It’s what got Mark Watney stuck planting potatoes in his own crap in The Martian.
Now, dust storms aren’t quite that bad – but NASA will have to account for them as they gear up to send the first astronauts to the red planet.
NASA researchers published a prediction earlier this week for the next global dust storm. Their prediction is based on a historical pattern they discovered.
“Mars will reach the midpoint of its current dust storm season on October 29th of this year. Based on the historical pattern we found, we believe it is very likely that a global dust storm will begin within a few weeks or months of this date,” James Shirley, a planetary scientist at NASA’s Jet Propulsion Laboratory.
The graphic above shows a similarity between 2016 (the dark blue line) and five previous years when Mars experienced global dust storms (orange lines and band). That’s contrasted with years where no global dust storm formed (blue-green lines and band).
Dust storms on Mars aren’t all that rare. But most tend to be local. During Mars’ southern spring and summer, some of these local storms can grow into regional ones. And a few of these regional ones expand into mammoth storms shrouding the entire planet in haze.
Two images captured by NASA’s Mars Global Surveyor orbiter in 2001 shows two different Mars’. Here’s the red planet with clear skies in late June 2001 (left).
Just weeks later, most of its surface features are blanketed by a thick layer of haze (right). During the height of these global storms, dust can reach altitudes of more than 37 miles.
NASA knows about nine global Martian dust storms since 1924. The last five occurred in 1977, 1982, 1994, 2001 and 2007. The number is assumed to be higher, but you can’t document what you can’t see. Orbiters weren’t always around Mars.
The 2007 dust storm was the first significant threat to Martian rovers according to JPL’s John Callas. He serves as project manager for Spirit and Opportunity. “We had to take special measures to enable their survival for several weeks with little sunlight to keep them powered. Each rover powered up only a few minutes each day, enough to warm them up, then shut down to the next day without even communicating with Earth. For many days during the worst of the storm, the rovers were completely on their own.”
We’ll see how this prediction pans out. Understanding Mars’ dust season and when global storms may form is critical for a manned mission. Astronauts would not have to worry about the wind all that much. But the dust? It would potentially wreak havoc on electronics and solar energy.
Shirley detailed the historic pattern he used for this prediction in a 2015 paper. He found the orbital motion of Mars is linked to when global dust storms form. I’ll let NASA explain.
Other planets have an effect on the momentum of Mars as it orbits the solar system’s center of gravity. This effect on momentum varies with a cycle time of about 2.2 years, which is longer than the time it takes Mars to complete each orbit: about 1.9 years. The relationship between these two cycles changes constantly. Shirley found that global dust storms tend to occur when the momentum is increasing during the first part of the dust storm season. None of the global dust storms in the historic record occurred in years when the momentum was decreasing during the first part of the dust storm season.
If Shirley is right, we should see Mars turn into a cloudy ball of orange-ish haze sometime in the next few months.