Saturn’s moon Titan is alone among the Solar System’s moons. It’s the only one with any atmosphere to speak of. Other moons may have thin, largely insignificant atmospheres, like Ganymede with its potential oxygen atmosphere. But Titan’s atmosphere is dense, and rich in nitrogen.
A new study shows that Titan’s atmosphere and winds might produce dust devils similar to Earth’s.
The InSight lander has been on the surface of Mars for about a year, and a half dozen papers were just published outlining some results from the mission. Though InSight’s primary mission is to gather evidence on the interior of Mars—InSight stands for Interior Exploration using Seismic Investigations, Geodesy, and Heat Transport—the lander also keeps track of Martian Meteorology. A new paper reports that InSight has found gravity waves, swirling dust devils, and a steady background rumble of infrasound.
There may be no life on Mars, but there’s still a lot going on there. The Martian surface is home to different geological process, which overlap and even compete with each other to shape the planet. Orbiters with powerful cameras give us an excellent view of Mars’ changing surface.
We live in a time when our spacecraft orbiting Mars at an altitude of about 300 km. can snap photos of a dust devil and transmit them back to us so we can share them on the internet. Not only that, but we have rovers wandering around on the surface taking pictures of the dust storms, too. Big deal, you say? So what, you say?
Furthermore they whip up the dust more easily in the lower gravity field on Mars compared to Earth. Mars gravity is about one third of Earth’s.
Right now it’s summer inside the rovers southern hemisphere landing site at Gale Crater. And summer is the windiest time of the Martian year.
“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,” as described by researchers.
So now is the best time to observe and photograph the dusty whirlwinds in action as they flitter amazingly across the craters surface carrying dust in their wake.
Therefore researchers are advantageously able to utilize Curiosity in a new research campaign that “focuses on modern wind activity in Gale” on the lower slope of Mount Sharp — a layered mountain inside the crater.
Indeed, this past month Curiosity began her second sand dune campaign focusing on investigating active dunes on the mountain’s northwestern flank that are ribbon-shaped linear dunes.
“In these linear dunes, the sand is transported along the ribbon pathway, while the ribbon can oscillate back and forth, side to side,” said Nathan Bridges, a Curiosity science team member at the Johns Hopkins University Applied Physics Laboratory in Laurel, Maryland, in a statement.
These new dunes are different from those investigated during the first dune campaign back in late 2015 and early 2016 that examined crescent-shaped dunes, including Namib Dune in our mosaic below.
The initial dune campaign actually involved the first ever up-close study of active sand dunes anywhere other than Earth, as I reported at the time.
By snapping a series of targeted images pointed in just the right direction using the rovers mast mounted navigation cameras, or navcams, the researchers have composed a series of ‘Dust Devil’ movies – gathered together here for your enjoyment.
“We’re keeping Curiosity busy in an area with lots of sand at a season when there’s plenty of wind blowing it around,” said Curiosity Project Scientist Ashwin Vasavada of NASA’s Jet Propulsion Laboratory, Pasadena, California.
“One aspect we want to learn more about is the wind’s effect on sorting sand grains with different composition. That helps us interpret modern dunes as well as ancient sandstones.”
The movies amply demonstrate that Mars is indeed an active world and winds are by far the dominant force shaping and eroding the Red Planets alien terrain – despite the thin atmosphere less than 1 percent of Earth’s.
Indeed scientists believe that wind erosion over billions of years of time is what caused the formation of Mount Sharp at the center of Gale Crater by removing vast amounts of dust and sedimentary material — about 15,000 cubic miles (64,000 cubic kilometers) — as Mars evolved from a wet world to the dry, desiccated planet we see today.
Gale crater was originally created over 3.6 billion years ago when a gigantic asteroid or comet smashed into Mars. The devastating impact “excavated a basin nearly 100 miles (160 kilometers) wide. Sediments including rocks, sand and silt later filled the basin, some delivered by rivers that flowed in from higher ground surrounding Gale.”
Winds gradually carved away so much sediment and dirt that we are left with the magnificent mountain in view today.
The whirlwinds called “dust devils” have been recorded moving across terrain in the crater, in sequences of afternoon images taken several seconds apart.
The contrast has been enhanced to better show the dust devils in action.
Watch this short NASA video showing Martian Dust Devils seen by Curiosity:
Video Caption: Dust Devils On Mars Seen by NASA’s Curiosity Rover. On recent summer afternoons on Mars, navigation cameras aboard NASA’s Curiosity Mars rover observed several whirlwinds carrying Martian dust across Gale Crater. Dust devils result from sunshine warming the ground, prompting convective rising of air. All the dust devils were seen in a southward direction from the rover. Timing is accelerated and contrast has been modified to make frame-to-frame changes easier to see. Credit: NASA/JPL
The team is also using the probes downward-looking Mars Descent Imager (MARDI) camera for a straight down high resolution up-close view looking beneath the rover. The purpose is to check for daily movement of the dunes she is sitting on to see “how far the wind moves grains of sand in a single day’s time.”
These dune investigations have to be done now, because the six wheeled robot will soon ascend Mount Sharp, the humongous layered mountain at the center of Gale Crater.
Ascending and diligently exploring the sedimentary lower layers of Mount Sharp, which towers 3.4 miles (5.5 kilometers) into the Martian sky, is the primary destination and goal of the rovers long term scientific expedition on the Red Planet.
“Before Curiosity heads farther up Mount Sharp, the mission will assess movement of sand particles at the linear dunes, examine ripple shapes on the surface of the dunes, and determine the composition mixture of the dune material,” researchers said.
Curiosity is also using the science instruments on the robotic arm turret to gather detailed research measurements with the cameras and spectrometers.
As of today, Sol 1625, March 2, 2017, Curiosity has driven over 9.70 miles (15.61 kilometers) since its August 2012 landing inside Gale Crater, and taken over 391,000 amazing images.
Stay tuned here for Ken’s continuing Earth and planetary science and human spaceflight news.
NASA’s CuriosityMars Science Laboratory (MSL) rover successfully bored a brand new hole in Mars at a tantalizing sandstone outcrop in the ‘Lubango’ fracture zone this past weekend on Sol 1320, Apr. 23, and is now carefully analyzing the shaken and sieved drill tailings for clues to Mars watery past atop the Naukluft Plateau.
“We have a new drill hole on Mars!” reported Ken Herkenhoff, Research Geologist at the USGS Astrogeology Science Center and an MSL science team member, in a mission update.
“All of the activities planned for last weekend have completed successfully.”
“Lubango” counts as the 10th drilling campaign since the one ton rover safely touched down on the Red Planet some 44 months ago inside the targeted Gale Crater landing site, following the nailbiting and never before used ‘sky crane’ maneuver.
After transferring the cored sample to the CHIMRA instrument for sieving it, a portion of the less than 0.15 mm filtered material was successfully delivered this week to the CheMin miniaturized chemistry lab situated in the rovers belly.
CheMin is now analyzing the sample and will return mineralogical data back to scientists on earth for interpretation.
The science team selected Lubango as the robots 10th drill target after determining that it was altered sandstone bedrock and had an unusually high silica content based on analyses carried out using the mast mounted ChemCam laser instrument.
Indeed the rover had already driven away for further scouting and the team then decided to return to Lubango after examining the ChemCam results. They determined the ChemCam and other data observation were encouraging enough – regarding how best to sample both altered and unaltered Stimson bedrock – to change course and drive backwards.
Lubango sits along a fracture in an area that the team dubs the Stimson formation, which is located on the lower slopes of humongous Mount Sharp inside Gale Crater.
Since early March, the rover has been traversing along a rugged region dubbed the Naukluft Plateau.
“The team decided to drill near this fracture to better understand both the altered and unaltered Stimson bedrock,” noted Herkenhoff.
See our photo mosaic above showing the geologically exciting terrain surrounding Curiosity with its outstretched 7-foot-long (2-meter-long) robotic arm after completing the Lubango drill campaign on Sol 1320. The mosaic was created by the imaging team of Ken Kremer and Marco Di Lorenzo.
Its again abundantly clear from the images that beneath the rusty veneer of the Red Planet lies a greyish interior preserving the secrets of Mars ancient climate history.
The team then commanded Curiosity to dump the unsieved portion of the sample onto the ground and examine the leftover drill tailing residues with the Mastcam, Navcam, MAHLI multispectral characterization cameras and the APXS spectrometer. ChemCam is also being used to fire laser shots in the wall of the drill hole to make additional chemical measurements.
To complement the data from Lubango, scientists are now looking around the area for a suitable target of unaltered Stimson bedrock as the 11th drill target.
“The color information provided by Mastcam is really helpful in distinguishing altered versus unaltered bedrock,” explained MSL science team member Lauren Edgar, Research Geologist at the USGS Astrogeology Science Center, in a mission update.
The ChemCam laser has already shot at the spot dubbed “Oshikati,” a potential target for the next drilling campaign.
“On Sunday we will drive to our next drilling location, which is on a nearby patch of normal-looking Stimson sandstone,” wrote Ryan Anderson, planetary scientist at the USGS Astrogeology Science Center and a member of the ChemCam team on MSL in today’s (Apr. 28) mission update.
As time permits, the Navcam imager is also being used to search for dust devils.
As I reported here, Opportunity recently detected a beautiful looking dust devil on the floor of Endeavour crater on April 1. Dust devil detections by the NASA rovers are relatively rare.
Curiosity has been driving to the edge of the Naukluft Plateau to reach the interesting fracture zone seen in orbital data gathered from NASA’s Mars orbiter spacecraft.
The rover is almost finished crossing the Naukluft Plateau which is “the most rugged and difficult-to-navigate terrain encountered during the mission’s 44 months on Mars,” says NASA.
Just how dangerous are the terrifying dust storms that swarm Mars?
Brave explorers trek across the red dunes of Mars when a dangerous dust storm blows in. In moments, our astronauts are blasted by gale force winds and driving sand, reducing visibility to zero. The brave heroes stumble desperately through the driving onslaught, searching in vain for shelter from the catastrophic conditions. One is blown into a ravine, or right to the edge of the cliff, requiring a dramatic rescue and likely a terrible terrible sacrifice and important parting words showing the true mettle of our heroes.
“Tell my Asuka… printed body pillow… I loved her…”
Will they make it? Why the heck would anyone land on that dusty irradiated death trap? Actually, a better question might be “Why do writers lean so hard on this trope?”. I’m looking at you Andy Weir.
Martian dust storms don’t just come from the fevered imagination of the same sci-fi writer who gave us a lush Venusian jungle, Saturnalian lava flats and Moon floor cheese. These dust storms are all too real and they drive at serious windspeeds.
NASA’s Viking landers clocked them at 100 km/h during dust storm season. Which is a thing on Mars. The landers sheltered enough from the big storms that they probably didn’t experience the greatest winds they’re capable of.
Scientists have seen evidence that sand is shifted around on the surface of Mars, and the regolith requires high wind speeds to pick it up and shove it around. Dust devils spin up across the surface, and rotate at hurricane speeds.
When the wind is above 65 km/h, it’s fast enough to pick up dust particles and carry them into the atmosphere encasing the planet in a huge, swirling, shroud. Freaked out yet? Is this dangerous? It sure sounds dangerous.
Apologies to all the fearmongering sci-fi writers, but actually, it’s not that dangerous. Here’s why.
First off, you’re not on Mars. It’s a book. Second, it’s a totally different experience on Earth. Here when you feel the wind blasting you in the face, or watch it dismantle a house during a tornado, it’s the momentum of the air particles hammering into it.
That momentum comes from air particle density and their velocity. Sadly, the density of the atmosphere on Mars is a delicate 1% of what we’re used to. It’s got the velocity, but it just doesn’t have the density.
It’s the difference between getting hit by a garden hose and a firehose with the same nozzle speed. One would gets you soaked, the other can push you down the street and give you bruises.
To feel a slight breeze on Mars similar to Earth, you multiply the wind speed by 10. So, if the wind was going about 15 km/h here, you’d need to be hit by winds going about 150 km/h there to have the same experience.
It’s not impossible for winds to go that fast on Mars, but that’s still not enough wind to fly a kite. To get it off the ground your mission buddy holds the kite, and you run around in the dumb Martian sand like a try-hard ass.
It would fly for a second and then crash down. You’d wonder why you even brought a kite to Mars in the first place because it’s NEVER windy enough.
Boo hoo. Your Mars kite doesn’t work. Good news! You’re on Mars!
Bad news. It was a one way trip. Good news! A wizard has made you immortal!
Bad news. The wizard has brought to life the entire fictional cast of the Twilight series and they’re also there and immortal. Have fun brooding with your new dorky friends, FOR ETERNITY.
What I’m saying is you could stand on the red planet restaurant patio and laugh at anything the weather system could throw at you. That is unless, you’re solar powered.
Mars gets regular dust storms. From time to time, they can get truly global. In 2001, a storm picked up enough dust to shroud the entire planet in a red haze. Temperatures went up as dust helped trap heat in the atmosphere. This storm lasted for 3 months before temperatures cooled, and the dust settled back down again.
During a storm in 2007, dust blocked 99% of the light reaching the solar panels of the Opportunity rover. This severely decreased the energy it had to power its instruments, and most importantly, the heaters. Ultimately, it was possible that the cold could kill the rover, if the dust hadn’t subsided quickly enough.
If you happen to see a movie or read a book about an astronaut on Mars dealing with a dangerous dust storm, don’t worry. They’ll be fine, the wind won’t shred them to pieces. Instead, focus on unbreathably thin atmosphere, the bone chilling cold, or the constant deadly radiation.
That and where’s their food come from again? Well, now you know dust storms aren’t a big issue. Want to travel to Mars? Tell us in the comments below.
If you haven’t checked it out yet, go read “The Martian”. Jay and I loved the pants off it and we can’t wait to see the film version.
In this latest update from the MSL team, Ashwin Vasavada, the Deputy Project Scientist, explains how Curiosity has been monitoring the winds and radiation levels in Gale Crater. Curiosity has also been looking for dust devils — the small dust storms that have been seen by other spacecraft as they whirl around Mars. While Curiosity hasn’t been able to ‘see’ them by taking images directly, other instruments indicate dust devils may be whirling right over the rover.
The team said that during the first 12 weeks after Curiosity landed in Gale Crater, they have analyzed data from more than 20 atmospheric events with at least one characteristic of a whirlwind recorded by the Rover Environmental Monitoring Station (REMS) instrument. Those characteristics can include a brief dip in air pressure, a change in wind direction, a change in wind speed, a rise in air temperature or a dip in ultraviolet light reaching the rover. Two of the events included all five characteristics.
Vasavada said that the winds blow from all directions where the rover sits, in between the central mound of Gale Crater (Aeolis Mons/Mt. Sharp) and the rim of the crater, which makes it an area ripe for dust devils.
Vasavada also points out that the Spirit and Opportunity rovers were able to capture dust devils in their own vicinity, which was an exciting accomplishment. Curiosity’s MastCams can take 720p (1280×720 pixels) high-definition video at a rate of about 10 frames per second, so if the team was ever lucky enough to capture a dust devil in action, it would be our best-ever view of a dust devil on the surface of Mars, and would be tremendously exciting.
Here’s a huge dust devil captured from orbit by the HiRISE camera on the Mars Reconnaissance Orbiter:
A Martian dust devil roughly 12 miles (20 kilometers) high was captured winding its way along the Amazonis Planitia region of Northern Mars on March 14, 2012 by the High Resolution Imaging Science Experiment (HiRISE) camera on NASA’s Mars Reconnaissance Orbiter. Despite its height, the plume is little more than three-quarters of a football field wide (70 yards, or 70 meters). Image credit: NASA/JPL-Caltech/UA
Methane on Mars has long perplexed scientists; the short-lived gas has been measured in surprising quantities in Mars’ atmosphere over several seasons, sometimes in fairly large plumes. Scientists have taken this to be evidence of Mars being an ‘active’ planet, either geologically or biologically. But a group of researchers from Mexico have come up with a different – and rather unexpected – source of methane: dust storms and dust devils.
“We propose a new production mechanism for methane based on the effect of electrical discharges over iced surfaces,” reports a paper published in Geophysical Research letters, written by a team led by Arturo Robledo-Martinez from the Universidad Autónoma Metropolitana, Azcapotzalco, Mexico.
“The discharges, caused by electrification of dust devils and sand storms, ionize gaseous CO2 and water molecules and their byproducts recombine to produce methane.”
In a laboratory simulation, they showed that that pulsed electrical discharges over ice samples in a synthetic Martian atmosphere produced about 1.41×1016 molecules of methane per joule of applied energy. The results of the electrical discharge experiment were compared with photolysis induced with UV laser radiation and it was found that both produce methane, although the efficiency of photolysis is one-third of that of the discharge.
The scientists don’t rule out that methane may indeed come from other sources as well, but the way that dust devils and storms can quickly form means they can also quickly generate methane. “The present mechanism may be acting in parallel with other proposed sources but its main advantage is that it can generate methane very quickly and thus explain the generation of plumes,” the team writes.
Methane has been observed in Mars’ atmosphere since 1999, but in 2009, scientists studying the atmosphere of Mars over several Martian years with telescopes here on Earth announced they had found three regions of active release of methane over areas that had evidence of ancient ground ice or flowing water.
They observed and mapped multiple plumes of methane on Mars, one of which released about 19,000 metric tons of methane. The plumes were emitted during the warmer seasons — spring and summer — which is also when dust devils tend to form.
Methane on Mars is enticing because it only lasts a few hundred years in Mars’ atmosphere, meaning it has to be continually replaced. And in the back of everyone’s minds has been the possibility of some sort of Martian life producing it.
“Methane is quickly destroyed in the Martian atmosphere in a variety of ways, so our discovery of substantial plumes of methane … indicates some ongoing process is releasing the gas,” said Dr. Michael Mumma of NASA’s Goddard Space Flight Center in Greenbelt, Md in 2009. “At northern mid-summer, methane is released at a rate comparable to that of the massive hydrocarbon seep at Coal Oil Point in Santa Barbara, Calif.”
The researchers in 2009 thought that the methane was being released from Mars’ interior, perhaps because the permafrost blocking cracks and fissures vaporized, allowing methane to seep into the Martian air.
The unknown has been where the methane has been coming from; if it is being released from the interior, it could be produced by either geologic processes such as serpentinization, a simple water/rock reaction or biologic processes of microbes (or something bigger) releasing methane as a waste product.
But if dust devils and dust storms can also produce methane, the mystery becomes a little more mundane.
The new research by the team from Mexico also mentioned fissures in the surface, but for a different reason, saying that the electric field of dust devils is amplified by the topology of the soil: “The electrical field produced by a dust devil can not only overcome the weak dielectric strength of the Martian atmosphere, but also penetrate into cracks on the soil and so reach the ice lying at the bottom, with added strength, due to the topography of the terrain,” the team wrote.
At a concentration of about 10 to 50 parts per billion by volume, methane is still a trace element in the Martian atmosphere, and indeed the sharp variations in its concentration that have been observed have been difficult to explain. Hopefully the research teams can coordinate follow-up observations of methane production during the dust devil and dust storm seasons on Mars.
The folk at JPL have kindly put together an animation of the gigantic Martian dust devil spotted by the Mars Reconnaissance Orbiter. The dust devil is roughly 20 kilometers (12 miles) high, churning through the Amazonis Planitia region of northern Mars, and this shows what the tall but thin dust devil would look like if you were observing it as you hovered around in your Mars helicopter or balloon.