A piece of Africa—actually lots of them—began to arrive in the Americas in June 2014. On June 23, a lengthy river of dust from western Africa began to push across the Atlantic Ocean on easterly winds. A week later, the influx of dust was affecting air quality as far away as the southeastern United States. This composite image, made with data from the Visible Infrared Imaging Radiometer Suite (VIIRS) on Suomi NPP, shows dust heading west toward South America and the Gulf of Mexico on June 25, 2014. The dust flowed roughly parallel to a line of clouds in the intertropical convergence zone, an area near the equator where the trade winds come together and rain and clouds are common. In imagery captured by the Moderate Resolution Imaging Spectroradiometer (MODIS), the dust appeared to be streaming from Mauritania, Senegal, and Western Sahara, though some of it may have originated in countries farther to the east. Saharan dust has a range of impacts on ecosystems downwind. Each year, dust events like the one pictured here deliver about 40 million tons of dust from the Sahara to the Amazon River Basin. The minerals in the dust replenish nutrients in rainforest soils, which are continually depleted by drenching, tropical rains. Research focused on peat soils in the Everglades show that African dust has been arriving regularly in South Florida for thousands of years as well. In some instances, the impacts are harmful. Infusion of Saharan dust, for instance, can have a negative impact on air quality in the Americas. And scientists have linked African dust to outbreaks of certain types of toxic algal blooms in the Gulf of Mexico and southern Florida. Read more: <a href="http://1.usa.gov/1snkzmS" rel="nofollow">1.usa.gov/1snkzmS</a> NASA images by Norman Kuring, NASA’s Ocean Color web. Caption by Adam Voiland. Credit: <b><a href="http://www.earthobservatory.nasa.gov/" rel="nofollow"> NASA Earth Observatory</a></b> <b><a href="http://www.nasa.gov/audience/formedia/features/MP_Photo_Guidelines.html" rel="nofollow">NASA image use policy.</a></b> <b><a href="http://www.nasa.gov/centers/goddard/home/index.html" rel="nofollow">NASA Goddard Space Flight Center</a></b> enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. <b>Follow us on <a href="http://twitter.com/NASAGoddardPix" rel="nofollow">Twitter</a></b> <b>Like us on <a href="http://www.facebook.com/pages/Greenbelt-MD/NASA-Goddard/395013845897?ref=tsd" rel="nofollow">Facebook</a></b> <b>Find us on <a href="http://instagram.com/nasagoddard?vm=grid" rel="nofollow">Instagram</a></b>

On an early fall afternoon in Ganges Chasma Valles Marineris, NASA Mars Reconnaissance Orbiter spacecraft managed to capture a cluster of eight dust devils, five of them in the enhanced color strip. They're together on a dark sandy surface that tilts slightly to the north, towards the Sun. Both of these factors help warm the surface and generate convection in the air above. The surface is streaked with the faint tracks of earlier dust devils. A pair of dust devils appears together at top right, spaced only 250 meters apart. These two have quite different morphologies. The bigger one (on the right) is about 100 meters in diameter and is shaped like a doughnut with a hole in the middle. Its smaller companion is more compact and plume-like, but it too has a small hole in the center, where the air pressure is lowest. It may be that the smaller dust devil is younger than the larger one. A row of four dust devils are in the middle of the color strip, separated by about 900 meters from one another. This image might answer some interesting questions about the behavior of dust devils. Dust devils are theoretically expected to migrate uphill on a sloping surface, or migrate downwind when there is a breeze. Where they are found close together in pairs, they are expected to rotate in opposite directions. HiRISE color observations can be used to determine the direction of rotation and-for fast moving dust devils-the direction of their travel. This is because the different color observations (infrared, red, and blue) are taken at slightly different times. The differences between the earliest color observation and the last tell us about the changes that took place during that time interval. All this requires careful analysis, but if these dust devils are moving fast enough, and spaced closely enough, these here might display some interesting "social dynamics," possibly marching together and rotating in alternating directions. http://photojournal.jpl.nasa.gov/catalog/PIA20045

There are many dust devils on Mars -- little twisters that raise dust from the surface. They have also cleaned dust off of the solar panels of the rovers Opportunity and Spirit, improving the solar power production. (Spirit became stuck in 2009 and ceased communication a year later.) HiRISE sees many dust-devil tracks on Mars, but rarely captures an active feature because the images cover such small areas and because the typical time of day near 3 p.m. is past the peak heating and dust-devil activity. The map is projected here at a scale of 25 centimeters (9.8 inches) per pixel. [The original image scale is 29.5 centimeters (11.6 inches) per pixel (with 1 x 1 binning) to 58.9 centimeters (23.2 inches) per pixel (with 2 x 2 binning)]. North is up. http://photojournal.jpl.nasa.gov/catalog/PIA21457

This graphic indicates a similarity between 2016 (dark blue line) and five past years in which Mars has experienced a global dust storm (orange lines and band), compared to years with no global dust storm (blue-green lines and band). The arrow nearly midway across in the dark blue line indicates the Mars time of year in late September 2016. A key factor in the graph is the orbital angular momentum of Mars, which would be steady in a system of only one planet orbiting the sun, but varies due to relatively small effects of having other planets in the solar system. The horizontal scale is time of year on Mars, starting at left with the planet's farthest distance from the sun in each orbit. This point in the Mars year, called "Mars aphelion," corresponds to late autumn in the southern hemisphere. Numeric values on the horizontal axis are in Earth years; each Mars year lasts for about 1.9 Earth years. The vertical scale bar at left applies only to the black-line curve on the graph. The amount of solar energy entering Mars' atmosphere (in watts per square meter) peaks at the time of year when Mars is closest to the sun, corresponding to late spring in the southern hemisphere. The duration of Mars' dust storm season, as indicated, brackets the time of maximum solar input to the atmosphere. The scale bar at right, for orbital angular momentum, applies to the blue, brown and blue-green curves on the graph. The values are based on mass, velocity and distance from the gravitational center of the solar system. Additional information on the units is in a 2015 paper in the journal Icarus, from which this graph is derived. The band shaded in orange is superimposed on the curves of angular momentum for five Mars years that were accompanied by global dust storms in 1956, 1971, 1982, 1994 and 2007. Brown diamond symbols on the curves for these years in indicate the times when the global storms began. The band shaded blue-green lies atop angular momentum curves for six years when no global dust storms occurred: 1939, 1975, 1988, 1998, 2000 and 2011. Note that in 2016, as in the pattern of curves for years with global dust storms, the start of the dust storm season corresponded to a period of increasing orbital angular momentum. In years with no global storm, angular momentum was declining at that point. Observations of whether dust from regional storms on Mars spreads globally in late 2016 or early 2017 will determine whether this correspondence holds up for the current Mars year. http://photojournal.jpl.nasa.gov/catalog/PIA20855

The view from May shows Valles Marineris chasms (left), Meridiani center, an autumn dust storm in Acidalia (top) and the early spring south polar cap (bottom). The view from July shows the same regions, but most of the surface was obscured by the planet-encircling dust cloud and haze. Movies are available at https://photojournal.jpl.nasa.gov/catalog/PIA22487

These two views from NASA's Curiosity rover, acquired specifically to measure the amount of dust inside Gale Crater, show that dust has increased over three days from a major Martian dust storm. The left-hand image shows a view of the east-northeast rim of Gale Crater on June 7, 2018 (Sol 2074); the right-hand image shows a view of the same feature on June 10, 2018 (Sol 2077). The images were taken by the rover's Mastcam. https://photojournal.jpl.nasa.gov/catalog/PIA22520

In the Electrostatics and Surface Physics Laboratory at NASA's Kennedy Space Center in Florida on Thursday, July 19, 2018, an experiment is underway in which an Electrostatic Dust Shield was been covered with dust similar to that which may be encountered by astronauts exploring the Moon or Mars. When activated, the device shook off the dust. Scientists are developing the dust shield to help mitigate the problem of dust on equipment, astronauts' space suits and helmet visors. The device is slated for analysis aboard International Space Station in the spring of 2019 to verify the effects of the space environment.

In the Electrostatics and Surface Physics Laboratory at NASA's Kennedy Space Center in Florida on Thursday, July 19, 2018, an experiment is underway in which an Electrostatic Dust Shield was been covered with dust similar to that which may be encountered by astronauts exploring the Moon or Mars. When activated, the device shook off the dust. Scientists are developing the dust shield to help mitigate the problem of dust on equipment, astronauts' space suits and helmet visors. The device is slated for analysis aboard International Space Station in the spring of 2019 to verify the effects of the space environment.

In the Electrostatics and Surface Physics Laboratory at NASA's Kennedy Space Center in Florida on Thursday, July 19, 2018, an experiment is underway in which an Electrostatic Dust Shield was been covered with dust similar to that which may be encountered by astronauts exploring the Moon or Mars. When activated, the device shook off the dust. Scientists are developing the dust shield to help mitigate the problem of dust on equipment, astronauts' space suits and helmet visors. The device is slated for analysis aboard International Space Station in the spring of 2019 to verify the effects of the space environment.

In the Electrostatics and Surface Physics Laboratory at NASA's Kennedy Space Center in Florida on Thursday, July 19, 2018, an experiment is underway in which an Electrostatic Dust Shield was been covered with dust similar to that which may be encountered by astronauts exploring the Moon or Mars. After activation, the device shakes off the dust. Scientists are developing the dust shield to help mitigate the problem of dust on equipment, astronauts' space suits and helmet visors. The device is slated for analysis aboard International Space Station in the spring of 2019 to verify the effects of the space environment.

In the Electrostatics and Surface Physics Laboratory at NASA's Kennedy Space Center in Florida on Thursday, July 19, 2018, an experiment is underway in which an Electrostatic Dust Shield has been covered with dust similar to that which may be encountered by astronauts exploring the Moon or Mars. When activated, the device shakes off the dust. Scientists are developing the dust shield to help mitigate the problem of dust on equipment, astronauts' space suits and helmet visors. The device is slated for analysis aboard International Space Station in the spring of 2019 to verify the effects of the space environment.

In the Electrostatics and Surface Physics Laboratory at NASA's Kennedy Space Center in Florida on Thursday, July 19, 2018, an experiment is underway in which an Electrostatic Dust Shield was been covered with dust similar to that which may be encountered by astronauts exploring the Moon or Mars. After activation, the device shook off the dust. Scientists are developing the dust shield to help mitigate the problem of dust on equipment, astronauts' space suits and helmet visors. The device is slated for analysis aboard International Space Station in the spring of 2019 to verify the effects of the space environment.

On Thursday, July 19, 2018, Dr. Carlos Calle, lead scientist in the Electrostatics and Surface Physics Laboratory at NASA's Kennedy Space Center in Florida, activates an experiment in which an Electrostatic Dust Shield has been covered with dust similar to that which may be encountered by astronauts exploring the Moon or Mars. When activated, the device shakes off the dust. Scientists are developing the dust shield to help mitigate the problem of dust on equipment, astronauts' space suits and helmet visors. The device is slated for analysis aboard International Space Station in the spring of 2019 to verify the effects of the space environment.

In the Electrostatics and Surface Physics Laboratory at NASA's Kennedy Space Center in Florida on Thursday, July 19, 2018, an experiment is underway in which an Electrostatic Dust Shield was been covered with dust similar to that which may be encountered by astronauts exploring the Moon or Mars. After activation, the device shakes off the dust. Scientists are developing the dust shield to help mitigate the problem of dust on equipment, astronauts' space suits and helmet visors. The device is slated for analysis aboard International Space Station t in the spring of 2019 o verify the effects of the space environment.

On Thursday, July 19, 2018, Dr. Carlos Calle, lead scientist in the Electrostatics and Surface Physics Laboratory at NASA's Kennedy Space Center in Florida, shows an Electrostatic Dust Shield that had been covered with dust similar to that which may be encountered by astronauts exploring the Moon or Mars. When activated, the device shook off the dust. Scientists are developing the dust shield to help mitigate the problem of dust on equipment, astronauts' space suits and helmet visors. The device is slated for analysis aboard International Space Station in the spring of 2019 to verify the effects of the space environment.

In the Electrostatics and Surface Physics Laboratory at NASA's Kennedy Space Center in Florida on Thursday, July 19, 2018, an Electrostatic Dust Shield has been covered with dust similar to that which may be encountered by astronauts exploring the Moon or Mars. Scientists are developing the dust shield to help mitigate the problem of dust on equipment, astronauts' space suits and helmet visors. The device is slated for analysis aboard International Space Station in the spring of 2019 to verify the effects of the space environment.

Dust Devils

Raising Dust

Dust Event

Dust Storms

Dust Storm

Two images from the Mast Camera (Mastcam) on NASA's Curiosity rover depict the change in the color of light illuminating the Martian surface since a dust storm engulfed Gale Crater. The left image shows the "Duluth" drill site on Sol 2058 (May 21, 2018); the right image is from Sol 2084 (June 17). The cherry red color in the post-storm image is due to a few factors. One difference between the two images is exposure time: the dust over Curiosity creates low-lighting conditions that require longer exposure times for the cameras. The pre-storm image had an exposure time of 7.3 milliseconds, which is normal for the rover; the later image had an exposure time that was 66 milliseconds -- or nine times longer. But a primary factor is red light being filtered through the dust; very little green and essentially no blue light makes it through the dust cloud. It's not unlike the way a forest fire changes the color of light, or a red stage light filters the other colors out. Though the first pre-storm image was taken at an earlier time of day, it has a much deeper shadow than the second image. That is because the whole sky is red and illuminating the rock from all sides. Individual images are available at https://photojournal.jpl.nasa.gov/catalog/PIA22330

This global map of Mars shows a growing dust storm as of June 6, 2018. The map was produced by the Mars Color Imager (MARCI) camera on NASA's Mars Reconnaissance Orbiter spacecraft. The blue dot shows the approximate location of Opportunity. The storm was first detected on June 1. The MARCI camera has been used to monitor the storm ever since. Full dust storms like this one are not surprising, but are infrequent. They can crop up suddenly but last weeks, even months. During southern summer, sunlight warms dust particles, lifting them higher into the atmosphere and creating more wind. That wind kicks up yet more dust, creating a feedback loop that NASA scientists still seek to understand. https://photojournal.jpl.nasa.gov/catalog/PIA22329

Dr. Carlos Calle, lead scientist in the Electrostatics and Surface Physics Laboratory at NASA's Kennedy Space Center in Florida, prepares an Electrostatic Dust Shield for testing on Thursday, July 19, 2018. Scientists are developing the Electrostatic Dust Shield to help mitigate the problem of dust on equipment, astronauts' space suits and helmet visors of astronauts exploring the Moon or Mars. The device is slated for analysis aboard International Space Station in the spring of 2019 to verify the effects of the space environment.

Dr. Carlos Calle, lead scientist in the Electrostatics and Surface Physics Laboratory at NASA's Kennedy Space Center in Florida, prepares an Electrostatic Dust Shield for testing on Thursday, July 19, 2018. Scientists are developing the Electrostatic Dust Shield to help mitigate the problem of dust on equipment, astronauts' space suits and helmet visors of astronauts exploring the Moon or Mars. The device is slated for analysis aboard International Space Station in the spring of 2019 to verify the effects of the space environment.

In the Electrostatics and Surface Physics Laboratory at NASA's Kennedy Space Center in Florida, scientists are developing the Electrostatic Dust Shield to help mitigate the problem of dust on equipment, astronauts' space suits and helmet visors of astronauts exploring the Moon or Mars. The hardware in display on Thursday, July 19, 2018, is slated for testing the Electrostatic Dust Shield aboard International Space Station in the spring of 2019 to verify the effects of the space environment.

In the Electrostatics and Surface Physics Laboratory at NASA's Kennedy Space Center in Florida, an Electrostatic Dust Shield is prepared for testing on Thursday, July 19, 2018. Scientists are developing the Electrostatic Dust Shield to help mitigate the problem of dust on equipment, space suits and helmet visors of astronauts exploring the Moon or Mars. The device is slated for analysis aboard International Space Station in the spring of 2019 to verify the effects of the space environment.

In the Electrostatics and Surface Physics Laboratory at NASA's Kennedy Space Center in Florida, an Electrostatic Dust Shield is prepared for testing on Thursday, July 19, 2018. Scientists are developing the Electrostatic Dust Shield to help mitigate the problem of dust on equipment, space suits and helmet visors of astronauts exploring the Moon or Mars. The device is slated for analysis aboard International Space Station in the spring of 2019 to verify the effects of the space environment.

Dr. Carlos Calle, lead scientist in the Electrostatics and Surface Physics Laboratory at NASA's Kennedy Space Center in Florida, prepares an Electrostatic Dust Shield for testing on Thursday, July 19, 2018. Scientists are developing the Electrostatic Dust Shield to help mitigate the problem of dust on equipment, astronauts' space suits and helmet visors of astronauts exploring the Moon or Mars. The device is slated for analysis aboard International Space Station in the spring of 2019 to verify the effects of the space environment.

In the Electrostatics and Surface Physics Laboratory at NASA's Kennedy Space Center in Florida, an Electrostatic Dust Shield is seen prior to testing on Thursday, July 19, 2018. Scientists are developing the Electrostatic Dust Shield to help mitigate the problem of dust on equipment, astronauts' space suits and helmet visors of astronauts exploring the Moon or Mars. The device is slated for analysis aboard International Space Station in the spring of 2019 to verify the effects of the space environment.

In the Electrostatics and Surface Physics Laboratory at NASA's Kennedy Space Center in Florida, an Electrostatic Dust Shield is prepared for testing on Thursday, July 19, 2018. Scientists are developing the Electrostatic Dust Shield to help mitigate the problem of dust on equipment, space suits and helmet visors of astronauts exploring the Moon or Mars. The device is being prepared for analysis aboard International Space Station in the spring of 2019 to verify the effects of the space environment.

In the Electrostatics and Surface Physics Laboratory at NASA's Kennedy Space Center in Florida, an Electrostatic Dust Shield is seen prior to testing on Thursday, July 19, 2018. Scientists are developing the Electrostatic Dust Shield to help mitigate the problem of dust on equipment, space suits and helmet visors of astronauts exploring the Moon or Mars. The device is slated for analysis aboard International Space Station in the spring of 2019 to verify the effects of the space environment.

This set of images from NASA's Mars Reconnaissance Orbiter (MRO) shows a fierce, giant dust storm is kicking up on Mars, with rovers on the surface indicated as icons. The spread of the storm can be seen in the salmon-colored overlay. These images from MRO's Mars Color Imager start from May 31, when the dust event was first detected, and go through June 11, 2018. MRO creates global maps of Mars but roll maneuvers for targeted observations produce gaps in the coverage, which appear as black gores in the maps. On some days there are data drops where partial or full orbits of coverage are missing. Green and purple observed in the south polar region indicate saturated pixels. Latitude is indicated along the vertical axis. Longitude is indicated along the horizontal axis. https://photojournal.jpl.nasa.gov/catalog/PIA22519

This dust avalanche is located in part of Noctis Labyrinthus

Dust devils dance in the distance in this frame from a sequence of images taken by the Navigation Camera on NASA's Curiosity Mars rover on Feb. 12, 2017, during the summer afternoon of the rover's 1,607th Martian day, or sol. Within a broader context view, the rectangular area outlined in black was imaged multiple times over a span of several minutes to check for dust devils. Images from the period with most activity are shown in the inset area. The images are in pairs that were taken about 12 seconds apart, with an interval of about 90 seconds between pairs. Timing is accelerated and not fully proportional in this animation. One dust devil appears at the right edge of the inset -- toward the south from the rover -- in the first few frames. Another appears on the left -- toward south-southeast -- later in the sequence. Contrast has been modified to make frame-to-frame changes easier to see. A black frame is added between repeats of the sequence. Portions of Curiosity are visible in the foreground. The cylindrical UHF (ultra-high frequency) antenna on the left is used for sending data to Mars orbiters, which relay the data to Earth. The angled planes to the right of this antenna are fins of the rover's radioisotope thermoelectric generator, which provides the vehicle's power. The post with a knob on top at right is a low-gain, non-directional antenna that can be used for receiving transmissions from Earth, as backup to the main high-gain antenna (not shown here) used for that purpose. On Mars as on Earth, dust devils are whirlwinds that result from sunshine warming the ground, prompting convective rising of air that has gained heat from the ground. Observations of Martian dust devils provide information about wind directions and interaction between the surface and the atmosphere. An animation is available at http://photojournal.jpl.nasa.gov/catalog/PIA21482

The 2001 Great Dust Storms - Daedalia/Claritas/Syria Dust Plumes

Dust storm in Alaska captured by Aqua/MODIS on Nov. 17, 2013 at 21:45 UTC. When glaciers grind against underlying bedrock, they produce a silty powder with grains finer than sand. Geologists call it “glacial flour” or “rock flour.” This iron- and feldspar-rich substance often finds its ways into rivers and lakes, coloring the water brown, grey, or aqua. When river or lake levels are low, the flour accumulates on drying riverbanks and deltas, leaving raw material for winds to lift into the air and create plumes of dust. Scientists are monitoring Arctic dust for a number of reasons. Dust storms can reduce visibility enough to disrupt air travel, and they can pose health hazards to people on the ground. Dust is also a key source of iron for phytoplankton in regional waters. Finally, there is the possibility that dust events are becoming more frequent and severe due to ongoing recession of glaciers in coastal Alaska. To read more about dust storm in this region go to: <a href="http://earthobservatory.nasa.gov/IOTD/view.php?id=79518" rel="nofollow">earthobservatory.nasa.gov/IOTD/view.php?id=79518</a> Credit: NASA/GSFC/Jeff Schmaltz/MODIS Land Rapid Response Team <b><a href="http://www.nasa.gov/audience/formedia/features/MP_Photo_Guidelines.html" rel="nofollow">NASA image use policy.</a></b> <b><a href="http://www.nasa.gov/centers/goddard/home/index.html" rel="nofollow">NASA Goddard Space Flight Center</a></b> enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. <b>Follow us on <a href="http://twitter.com/NASA_GoddardPix" rel="nofollow">Twitter</a></b> <b>Like us on <a href="http://www.facebook.com/pages/Greenbelt-MD/NASA-Goddard/395013845897?ref=tsd" rel="nofollow">Facebook</a></b> <b>Find us on <a href="http://instagram.com/nasagoddard?vm=grid" rel="nofollow">Instagram</a></b>

Inside of the Electrostatics and Surface Physics Laboratory at NASA’s Kennedy Space Center in Florida, an electrodynamic dust shield (EDS) is in view on Jan. 18, 2023. The dust shield is one of the payloads that will fly aboard Firefly Aerospace’s Blue Ghost lunar lander as part of NASA’s Commercial Lunar Payload Services (CLPS) initiative. During the mission, EDS will generate a non-uniform electric field using varying high voltage on multiple electrodes. This traveling field, in turn, carries away the particles and has potential applications in thermal radiators, spacesuit fabrics, visors, camera lenses, solar panels, and many other technologies. The CLPS initiative is a key part of NASA’s Artemis lunar exploration efforts. The science and technology payloads sent to the Moon’s surface as part of the initiative will help lay the foundation for human missions and a sustainable human presence on the lunar surface.

Inside of the Electrostatics and Surface Physics Laboratory at NASA’s Kennedy Space Center in Florida, an electrodynamic dust shield (EDS) is in view on Jan. 18, 2023. The dust shield is one of the payloads that will fly aboard Firefly Aerospace’s Blue Ghost lunar lander as part of NASA’s Commercial Lunar Payload Services (CLPS) initiative. During the mission, EDS will generate a non-uniform electric field using varying high voltage on multiple electrodes. This traveling field, in turn, carries away the particles and has potential applications in thermal radiators, spacesuit fabrics, visors, camera lenses, solar panels, and many other technologies. The CLPS initiative is a key part of NASA’s Artemis lunar exploration efforts. The science and technology payloads sent to the Moon’s surface as part of the initiative will help lay the foundation for human missions and a sustainable human presence on the lunar surface.

This frame from a movie clip of hundreds of images from NASA's Mars Reconnaissance Orbiter shows a global map of Mars with atmospheric changes from Feb. 18, 2017 through March 6, 2017, a period when two regional-scale dust storms appeared. It combines hundreds of images from the Mars Color Imager (MARCI) camera on NASA's Mars Reconnaissance Orbiter. The date for each map in the series is given at upper left. Dust storms appear as pale tan. In the opening frames, one appears left of center, near the top (north) of the map, then grows in size as it moves south, eventually spreading to about half the width of the map after reaching the southern hemisphere. As the dust from that first storm becomes more diffuse in the south, another storm appears near the center of the map in the final frames. In viewing the movie, it helps to understand some of the artifacts produced by the nature of MARCI images when seen in animation. MARCI acquires images in swaths from pole-to-pole during the dayside portion of each orbit. The camera can cover the entire planet in just over 12 orbits, and takes about one day to accumulate this coverage. The individual swaths for each day are assembled into a false-color, map-projected mosaic for the day. Equally spaced blurry areas that run from south-to-north result from the high off-nadir viewing geometry in those parts of each swath, a product of the spacecraft's low orbit. Portions with sharper-looking details are the central part of an image, viewing more directly downward through less atmosphere than the obliquely viewed portions. MARCI has a 180-degree field of view, and Mars fills about 78 percent of that field of view when the camera is pointed down at the planet. However, the Mars Reconnaissance Orbiter often is pointed to one side or the other off its orbital track in order to acquire targeted observations by other imaging systems on the spacecraft. When such rolls exceed about 20 degrees, gaps occur in the mosaic of MARCI swaths. Other dark gaps appear where data are missing. It isn't easy to see the actual dust motion in the atmosphere in these images, owing to the apparent motion of these artifacts. However, by concentrating on specific surface features (craters, prominent ice deposits, etc.) and looking for the tan clouds of dust, it is possible to see where the storms start and how they grow, move and eventually dissipate. Movies are available at http://photojournal.jpl.nasa.gov/catalog/PIA21484

Dust slides are common in the dust covered region called Lycus Sulci. A large fracture is also visible in this image

Dust Devil Tracks

Dune and Dust Devil Tracks

Bright Dust Devil Tracks

Dust-covered Flow

May Dust Storm in Acidalia

Decay of a Martian Dust Storm

Dust Devil Streaks

Dust Devil Tracks

Autumn Dust Storm

A Year Worth of Tracks in the Dust

Before the Dust Settled

Autumn Dust Storm

A Mid-Summer Dust Devil

Polar Dust Storm

Dust Storm in Syria

Dust Devil Tracks

North Polar Dust Storm

Dust Devil Tracks

Dust Devil Tracks

Tikhonravov Crater Dust Avalanches

Dust-Raising Event

1997 Martian Dust Storm

Dust Devil Tracks

Big Dust Devils

Dust Devils Seen by Spirit

Light Dust Devil Tracks

Daedalia Dust Devil

Dust Devil Tracks

Dust Devil Tracks

Martian Dust Devil Tracks

Isidis Dust Devil

September Dust Devil

Time for Dust Storms

Tithonium Dust Devil

Sweeping the Dust Away

Dust Devil Tracks

Pathfinder Spies Dust Devils

Dust Devil Tracks

Dust Devil Art

Dust Devil Tracks

Dust Devil Tracks

Southern Dust Devils

Dust Devil Tracks

Growth of a Dust Storm TES

Loire Dust Devil

Dust-Raising Event in Noachis

Hebes Chasma Dust Avalanches

Lycus Sulci Dust Avalanches

Dust and Sand Mixing

Kaiser Crater Dust Devils

Dune and Dust Devil Streaks

Argyre Dust Devil Tracks

Dust Devil Days

Dust Devil Art

Early Autumn Dust Storm

Dust Devil Tracks

Noachis Dust Storm

Dust Devil Tracks

Ares Vallis Dust Devil