Side-by-side movies reveal how dust has enveloped the red planet, thanks to the Mars Color Imager (MARCI) camera aboard NASA's Mars Reconnaissance Orbiter (MRO). The view from May shows the precipices of Valles Marineris (left), the Meridiani Center, an autumn jam in Acidalia (above) and the South African Pole Cap (below). The view from July shows the same regions, but most of the surface was obscured by the dust cloud and the nebula of the planet.
Over the past month, Mars has shown a spectacular show in our night sky. The show culminates on July 27, 201
For scientists watching the red planet from data collected by NASA orbiting satellites, last month was a godsend. Global dust storms, where an uncontrolled series of storms creates a cloud of dust so thick that it engulfs the planet, only appear every six to eight years (that's three to four Mars years). The scientists still do not understand why and how exactly these storms form and develop.
The dust storm was not good news for the NASA's occasional rover. NASA said it meant:
… a sudden decline in visibility from a clear, sunny day to a cloudy one. Since Opportunity is powered by solar energy, scientists had to stop scientific activities to conserve the Rovers' batteries. From 18 July, the rover received no answer.
Read more about Opportunity's Opportunity at NASA
But other NASA spacecraft – both on the ground and in orbit – are watching the dust storm. In fact, NASA said:
The Mars Reconnaissance Orbiter, Mars Odyssey and Mars Atmosphere and Volatile Evolution Orbiter (MAVEN) are all adjusting their observations of the red planet to this global storm study and learn more about the weather patterns of Mars. Meanwhile, the Curiosity Rover investigates the dust storm from the Martian surface.
The Mars Reconnaissance Orbiter has two instruments that investigate the dust storm. The Mars Color Imager trains the entire planet every afternoon to follow the evolution of the storm. In the meantime, the Mars Climate Sounder instrument measures how the temperature of the atmosphere changes with altitude. Rich Zurek of NASA's Jet Propulsion Laboratory, Pasadena, California, is the project scientist for the Mars Reconnaissance Orbiter. Zurak said:
The fact that one can start with a local storm that is no bigger than a small [U.S.] state and then triggers something that stirs up more dust and creates a fog that covers almost the entire planet, It's Noteworthy
The MAVEN orbiter has been orbiting Mars since 2014. Since entering Mars orbit, Bruce Jakosky, the orbiter's investigator
… we were waiting for a global dust storm.
NASA said that MAVEN does not investigate the dust storm itself. Instead:
… the MAVEN team wants to investigate how the dust storm affects the upper atmosphere of Mars, about 100 kilometers above the surface – where the dust is not enough. MAVENS mission is to find out what happened to the early atmosphere of Mars. We know that a few billion years ago, liquid water caused the surface of Mars to converge, meaning that its atmosphere must have been thicker and more insulating than Earth's.
Since MAVEN arrived on Mars in 2014, his research has revealed that this atmosphere was swept away by a stream of solar wind over several hundred million years ago, 3.5 to 4.0 billion years ago.
But there are still nuances to figure out how dust storms like the current affect how atmospheric molecules escape into space … For example, the dust storm acts as an atmospheric insulator that stores the heat from the sun. Does this warming change the way molecules escape the atmosphere?
Most NASA spacecraft investigate the dust storm from above. And the Rover Opportunity is currently not functional. But the Curiosity Rover – designed to explore the Gale Crater on Mars – does not suffer the same fate as Opportunity. That's because Curiosity is not powered by solar energy. It's a nuclear-powered science machine – and therefore largely immune to the dust-darkened sky of Mars – that still collects scientific data as the dust flies around it.
JPL's Ashwin Vasavada, Curiosy's project scientist, said:
We're working twice now. Our newly commissioned drill buys a fresh rock sample. But we also use instruments to study how the dust storm is developing.
Curiosity has a number of "eyes" that can determine the frequency and size of dust particles based on how they scatter and absorb light. These include his mastcam, ChemCam … his suite of weather instruments [called the Rover Environmental Monitoring Station, or REMS]. REMS can also help study atmospheric tides – pressure shifts that move as waves across the planet's thin air. These tides change dramatically depending on where the dust is global, not just in the Gale crater.
The Global Storm can also reveal secrets about Mars dust devils and winds. Dust devils can occur when the surface of the planet is hotter than the air above it. The heater generates air turbulence, some of which absorb dust and become dust devils. During a dust storm, there is less direct sunlight and lower daytime temperatures; that could mean that less devils swirl across the surface.
Even new holes can advance the dust storm science: Observing the small heaps of loose material generated by the curiosity drill is the best way to monitor winds.
Scientists expect the Mars dust storm to take another few months. Expect some new scientific results from this great opportunity to study nature in another world!
Bottom line: How do different NASA spacecraft investigate the progressive dust storm on Mars?