Storm chasing takes luck together with patience on Earth—and fifty-fifty to a greater extent than therefore on Mars. For scientists watching the Red Planet from information gathered yesteryear NASA's orbiters, the yesteryear calendar month has been a windfall. "Global" dust storms, where a runaway serial of storms creates a dust cloud therefore large it envelops the planet, solely seem every vi to 8 years (that's 3 to 4 Mars years). Scientists notwithstanding don't empathize why or how just these storms shape together with evolve.
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| Side-by-side movies shows how dust has enveloped the Red Planet, courtesy of the Mars Color Imager (MARCI) wide-angle photographic tv set camera onboard NASA's Mars Reconnaissance Orbiter (MRO) [Credit: NASA/JPL-Caltech/MSSS] |
For the Opportunity rover, that meant a precipitous driblet inward visibility from a clear, sunny twenty-four hr menses to that of an overcast one. Because Opportunity runs on solar energy, scientists had to suspend scientific discipline activities to save the rover's batteries. As of July 18th, no response has been received from the rover.
Luckily, all that dust acts every bit an atmospheric insulator, keeping nighttime temperatures from dropping downwards to lower than what Opportunity tin sack handle. But the nearly 15-year-old rover isn't out of the woods yet: it could direct hold weeks, or fifty-fifty months, for the dust to start settling. Based on the longevity of a 2001 global storm, NASA scientists guess it may last early on September earlier the haze has cleared plenty for Opportunity to ability upward together with telephone proper substantive upward home.
When the skies laid about to clear, Opportunity's solar panels may last covered yesteryear a fine cinema of dust. That could delay a recovery of the rover every bit it gathers liberate energy to recharge its batteries. H5N1 gust of air current would help, but isn't a requirement for a total recovery..
While the Opportunity squad waits inward earnest to take away heed from the rover, scientists on other Mars missions direct hold gotten a rare direct chances to report this head-scratching phenomenon.
The Mars Reconnaissance Orbiter, Mars Odyssey, together with Mars Atmosphere together with Volatile EvolutioN (MAVEN) orbiters are all tailoring their observations of the Red Planet to report this global tempest together with acquire to a greater extent than virtually Mars' conditions patterns. Meanwhile, the Curiosity rover is studying the dust tempest from the Martian surface.
Here's how each mission is currently studying the dust storm, together with what nosotros mightiness acquire from it:
Mars Odyssey
With the THEMIS musical instrument (Thermal Emission Imaging System), scientists tin sack rail Mars' surface temperature, atmospheric temperature, together with the total of dust inward the atmosphere. This allows them to sentinel the dust tempest grow, evolve, together with dissipate over time.
"This is i of the largest conditions events that we've seen on Mars," since spacecraft observations began inward the 1960s, said Michael Smith, a scientist at NASA's Goddard Spaceflight Center inward Greenbelt, Maryland who industrial plant on the THEMIS instrument. "Having unopen to other representative of a dust tempest actually helps us to empathize what's going on."
Since the dust tempest began, the THEMIS squad has increased the frequency of global atmospheric observations from every 10 days to twice per week, Smith said. One mystery they're notwithstanding trying to solve: How these dust storms cash inward one's chips global. "Every Mars year, during the dusty season, at that spot are a lot of local- or regional-scale storms that embrace i surface area of the planet," Smith said. But scientists aren't yet certain how these smaller storms sometimes grow to terminate upward encircling the entire planet.
Mars Reconnaissance Orbiter (MRO)
Mars Reconnaissance Orbiter has 2 instruments studying the dust storm. Each day, the Mars Color Imager (MARCI) maps the entire planet inward mid-afternoon to rail the development of the storm. Meanwhile, MRO's Mars Climate Sounder (MCS) musical instrument measures how the atmosphere's temperature changes alongside altitude. Since the terminate of May, the instruments direct hold observed the onslaught together with rapid expansion of a dust tempest on Mars.
With these data, scientists are studying how the dust tempest changes the planet's atmospheric temperatures. Just every bit inward Earth's atmosphere, changing temperature on Mars tin sack comport on air current patterns together with fifty-fifty the circulation of the entire atmosphere. This provides a powerful feedback: Solar heating of the dust lofted into the atmosphere changes temperatures, which changes winds, which may amplify the tempest yesteryear lifting to a greater extent than dust from the surface.
Scientists desire to know the details of the storm—where is the air rising or falling? How make the atmospheric temperatures immediately compare to a storm-less year? And every bit alongside Mars Odyssey, the MRO squad wants to know how these dust storms cash inward one's chips global.
"The real fact that y'all tin sack start alongside something that's a local storm, no bigger than a small-scale [U.S.] state, together with and therefore trigger something that raises to a greater extent than dust together with produces a haze that covers almost the entire planet is remarkable," said Rich Zurek of NASA's Jet Propulsion Laboratory, Pasadena, California, the projection scientist for MRO.
Scientists desire to discover out why these storms arise every few years, which is difficult to make without a long tape of such events. It'd last every bit if aliens were observing public together with seeing the climate effects of El Niño over many years of observations—they'd wonder why unopen to regions acquire extra rainy together with unopen to areas acquire extra dry out inward a seemingly regular pattern.
MAVEN
Ever since the MAVEN orbiter entered Mars' orbit, "one of the things we've been waiting for is a global dust storm," said Bruce Jakosky, the MAVEN orbiter's regulation investigator.
But MAVEN isn't studying the dust tempest itself. Rather, the MAVEN squad wants to report how the dust tempest affects Mars' upper atmosphere, virtually 62 miles (more than 100 kilometers) to a higher identify the surface—where the dust doesn't fifty-fifty reach. MAVEN's mission is to figure out what happened to Mars' early on atmosphere. We know that at unopen to betoken billions of years ago, liquid H2O pooled together with ran along Mars' surface, which way that its atmosphere must direct hold been thicker together with to a greater extent than insulating, similar to Earth's. Since MAVEN arrived at Mars inward 2014, its investigations direct hold establish that this atmosphere may direct hold been stripped away yesteryear a torrent of solar air current over several hundred 1000000 years, betwixt 3.5 together with 4.0 billion years ago.
But at that spot are notwithstanding nuances to figure out, such every bit how dust storms similar the electrical flow i comport on how atmospheric molecules escape into space, Jakosky said. For instance, the dust tempest acts every bit an atmospheric insulator, trapping oestrus from the Sun. Does this heating alter the way molecules escape the atmosphere? It is every bit good probable that, every bit the atmosphere warms, to a greater extent than H2O vapor rises high plenty to last broken downwards yesteryear sunlight, alongside the solar air current sweeping the hydrogen atoms into space, Jakosky said.
The squad won't direct hold answers for a piece yet, but each of MAVEN's 5 orbits per twenty-four hr menses volition proceed to render invaluable data.
Curiosity
Most of NASA's spacecraft are studying the dust tempest from above. The Mars Science Laboratory mission's Curiosity rover has a unique perspective: the nuclear-powered scientific discipline machine is largely immune to the darkened skies, allowing it to collect scientific discipline from within the beige veil enveloping the planet.
"We're working double-duty correct now," said JPL's Ashwin Vasavada, Curiosity's projection scientist. "Our newly recommissioned drill is acquiring a fresh stone sample. But nosotros are every bit good using instruments to report how the dust tempest evolves."
Curiosity has a publish of "eyes" that tin sack decide the abundance together with size of dust particles based on how they scatter together with absorb light. That includes its Mastcam, ChemCam, together with an ultraviolet sensor on REMS, its suite of conditions instruments. REMS tin sack every bit good assist report atmospheric tides—shifts inward pressure level that motion every bit waves across the entire planet's sparse air. These tides alter drastically based on where the dust is globally, non only within Gale crater.
The global tempest may every bit good break secrets virtually Martian dust devils together with winds. Dust devils tin sack occur when the planet's surface is hotter than the air to a higher identify it. Heating generates whirls of air, unopen to of which selection upward dust together with cash inward one's chips dust devils. During a dust storm, there's less straight sunlight together with lower daytime temperatures; this mightiness hateful fewer devils swirling across the surface.
Even novel drilling tin sack advance dust tempest science: watching the small-scale piles of loose cloth created yesteryear Curiosity's drill is the best way of monitoring winds.
Scientists think the dust tempest volition final at to the lowest degree a distich of months. Every fourth dimension y'all spot Mars inward the heaven inward the weeks ahead, recall how much information scientists are gathering to amend empathize the mysterious conditions of the Red Planet.
Author: Andrew Good | Source: Jet Propulsion Laboratory [July 19, 2018]
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