Under a largely cloudless sky, these sediments heat up by day and cool off quickly at night. As scientists say, they have low thermal inertia, meaning they change temperature easily. If you have ever walked barefoot on sand that was hot at noon yet cool after dark, you have personally experienced low thermal-inertia sediment.
Air rises when heated by hot ground, and the motion pulls in cooler air at ground level. Sometimes this creates a dust devil when fine particles of dust are swept up by the cooler air moving across the ground. More generally, temperature differences between one area and another cause air to flow between them, producing winds. Scientists have made only a few direct measurements of Martian wind speeds.
The Curiosity rover is making such measurements on Mars now. But studies of dust storms, cloud movements, and wind streaks suggest that winds can blow up to kilometers per hour 62 mph. However to a human standing on the surface, this would feel more like a light breeze than a tropical storm.
Driven by the wind, small particles skip, hop, bounce, and slide across the surface, chipping and eroding rocks as they go, in a process called saltation. In large quantities, loose particles form dunes. But Mars is a spinning planet, and this complicates wind patterns. At low latitudes, Hadley cell motion dominates. Named for English scientist George Hadley , who first described it on Earth, the pattern features heated air rising around the equator.
In a special NASA teleconference on June 13, researchers said that, while Mars' atmosphere is thin, there is still dust being raised. This could hypothetically complicate regular functioning and visibility for future crewed missions. Additionally, dust storms create "sort of a greenhouse effect in which the radiation that otherwise would be lost to space is trapped," heating up the planet, Rich Zurek, Mars Program Office chief scientist at NASA's Jet Propulsion Laboratory, said in the conference.
Humans on the Martian surface will already have to contend with radiation, and this effect will only increase the risk.
Plus, Martian storms can grow to epic scale: The researchers said the current storm is expanding and could potentially stretch across the entire planet, which humans have seen happen on Mars before.
So, a Martian dust storm likely won't strand any future space colonists or rip any antennas off of equipment, like what happened in "The Martian. Solar-powered tech will also continue to struggle against the dust that sticks to solar panels on rovers like Opportunity.
NASA is already seriously considering these potential threats to future space explorers. That may no longer be the case, according to Simone Silvestro, a research scientist at the National Institute for Astrophysics in Naples, Italy, and lead author of the study published in June in the Journal of Geophysical Research: Planets.
They compared images of these locations over 7. The findings were unexpected, Silvestro said, because megaripples are made up of coarse grains of sand, particularly at the crests of the rippled features.
Fine particles of dust can blow around during Martian dust storms, but it was not previously known if the wind on Mars was powerful enough to sculpt megaripples. Silvestro said the research could inform future human exploration of the planet, as scientists will need to understand how the Martian climate may affect astronaut crews.
The six-wheeled robotic explorer, named Perseverance, is expected to reach Mars in February, and Silvestro said the rover could get an up-close view of megaripples during its mission.
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