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& # 39; Storm Chasers & # 39; on Mars In search of dusty secrets



Side-by-side films show how dust has enveloped the Red Planet with the Mars Color Imager (MARCI) wide-angle camera aboard NASA's Mars Reconnaissance Orbiter (MRO). Credit: NASA / JPL-Caltech / MSSS

Hunting Storm requires luck and patience on Earth ̵

1; and more on Mars.

For scientists observing the Red Planet with NASA orbiting, last month was a godsend. "Global" dust storms, where an uncontrolled series of storms creates a cloud of dust that is so large that it surrounds the planet, appears only 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.

In June, one of these dust events quickly engulfed the planet. The scientists observed a dust storm on a smaller scale for the first time on May 30. He was global until June 20th.

For the Rover Opportunity, this meant a sudden drop 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. Since July 18, the rover has received no response.

Luckily, all the dust acts like an atmospheric insulator that drops nighttime temperatures to a level that Opportunity can handle. But the almost 15-year-old Rover is not yet off the hook: It could take weeks or even months to clear the dust. Based on the longevity of a global storm in 2001, NASA scientists estimate it could be early September before the veil for Opportunity has enough power to go home.

Credit: NASA

When the sky begins to clear up Solar panels can be covered with a fine dust film. This could delay a recovery of the rover as it gathers energy to recharge its batteries. A gust of wind would help, but is not a prerequisite for a full recovery.

While the Opportunity Team is seriously waiting to hear from the Rover, scientists from other Mars missions have been given a rare chance to examine this head. Scratching Phenomenon

The Orbiter Mars Reconnaissance Orbiters, Mars Odyssey and Mars Atmosphere and Volatile EvolutioN (MAVEN) tailor their observations of the Red Planet to study this global storm and to learn more about the weather patterns of Mars. Meanwhile, the Curiosity rover investigates the dust storm from the Martian surface.

Here you can see how each mission is currently investigating the dust storm and what we could learn from it:

Mars Odyssey [19659003] With the THEMIS (Thermal Emission Imaging System) instrument, scientists can measure the surface temperature, the atmospheric Measure the temperature and the amount of dust in the atmosphere. This allows them to observe how the dust storm grows, develops and dissolves over time.

"This is one of the biggest weather events we have seen on Mars," said Michael Smith, a scientist at NASA's Goddard Spaceflight Center in Greenbelt, Maryland, who works on the THEMIS instrument. "Another example of a dust storm really helps us understand what's going on."

Since the onset of the dust storm, the THEMIS team has increased the frequency of global atmospheric observations from 10 to 2 times a week, Smith said. A puzzle that they still try to solve: how these dust storms become global. "Every Martian year, during the dusty season, there are many local or regional storms that cover an area of ​​the planet," Smith said. But scientists are not yet sure how these smaller storms sometimes surround the entire planet.

Mars Reconnaissance Orbiter (MRO)

Mars Reconnaissance Orbiter has two instruments that investigate the dust storm. Every day, Mars Color Imager (MARCI) maps the entire planet in the afternoon to follow the evolution of the storm. Meanwhile, the Mars Climate Sounder (MCS) MRO meter measures how the temperature of the atmosphere changes with altitude. Since late May, the instruments have observed the onset and rapid spread of a dust storm on Mars.

Using this data, scientists are studying how the dust storm is altering the planet's atmospheric temperatures. Just like in the Earth's atmosphere, the temperature change on Mars can affect the wind patterns and even the circulation of the entire atmosphere. This provides strong feedback: solar heating of the dust into the atmosphere alters temperatures, which in turn alters the winds, which can aggravate the storm by lifting more dust off the surface.

Scientists want to know the details of the storm – where is the air rising or falling? What do the atmospheric temperatures now look like with a stormless year? And as with Mars Odyssey, the MRO team wants to know how these dust storms are becoming global.

"The fact that one can begin with something that is a local storm, no bigger than a small [U.S.] state, and then triggers something that stirs up more dust and creates a nebula that covers almost the entire planet 'is remarkable,' said Rich Zurek of NASA's Jet Propulsion Laboratory, Pasadena, California, the project scientist for MRO.

Scientists want to find out why these storms occur every few years, which is hard to do without a long history of such events. It would be as if aliens were watching Earth and observing El Niño's climate impacts for many years – wondering why some regions get particularly rainy and some areas seemingly dry in a seemingly regular pattern.

MAVEN

Since the MAVEN orbiter invaded Mars orbit, "one of the things we have been waiting for is a global dust storm," said Bruce Jakosky, the main writer of the MAVEN orbiter.

But MAVEN does not study the dust storm itself. Rather, 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 does not even reach. 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 arriving at Mars on MAVEN in 2014, his research has shown that this atmosphere was thrown by a stream of solar wind over several hundred million years from 3.5 to 4.0 billion years ago.

But there are still nuances on how dust storms like the current affect how atmospheric molecules escaped into space, Jakosky said. For example, the dust storm acts as an atmospheric insulator and captures heat from the sun. Does this heating change the way molecules escape the atmosphere? It is also likely that as the atmosphere warms, more water vapor rises high enough to be decomposed by sunlight, with the solar wind sweeping the hydrogen atoms into space, Jakosky said.

The team will not provide answers for one yet, but each of the five lanes of MAVEN per day will continue to provide invaluable data.

Curiosity

Most NASA spacecraft investigate the dust storm from above. The Curiosity Rover of the Mars Science Laboratory has a unique perspective: The nuclear-powered science machine is largely immune to the dark sky and allows science to be collected from the beige veil that surrounds the planet.

"We are working double duty now," said JPL Ashwin Vasavada, curiosity project scientist. "Our newly commissioned drill buys a fresh rock sample, but we also use instruments to study how the dust storm develops."

Curiosity has a set of "eyes" that indicate the frequency and size of dust particles based on it how they can scatter and absorb light. These include his mastcam, ChemCam and a UV sensor on REMS, his suite of weather instruments. 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; this 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 believe that the dust storm last at least a few months. Every time you see Mars in the sky in the coming weeks, remember how many data scientists are gathering to better understand the mysterious weather on the Red Planet.


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