Posted on by Jean Tate

Ozone on Mars: Two Windows Better Than One

An illustration showing the ESA's Mars Express mission. Credit: ESA/Medialab)


Understanding the present-day Martian climate gives us insights into its past climate, which in turn provides a science-based context for answering questions about the possibility of life on ancient Mars.

Our understanding of Mars’ climate today is neatly packaged as climate models, which in turn provide powerful consistency checks – and sources of inspiration – for the climate models which describe anthropogenic global warming here on Earth.

But how can we work out what the climate on Mars is, today? A new, coordinated observation campaign to measure ozone in the Martian atmosphere gives us, the interested public, our own window into just how painstaking – yet exciting – the scientific grunt work can be.

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The Martian atmosphere has played a key role in shaping the planet’s history and surface. Observations of the key atmospheric components are essential for the development of accurate models of the Martian climate. These in turn are needed to better understand if climate conditions in the past may have supported liquid water, and for optimizing the design of future surface-based assets at Mars.

Ozone is an important tracer of photochemical processes in the atmosphere of Mars. Its abundance, which can be derived from the molecule’s characteristic absorption spectroscopy features in spectra of the atmosphere, is intricately linked to that of other constituents and it is an important indicator of atmospheric chemistry. To test predictions by current models of photochemical processes and general atmospheric circulation patterns, observations of spatial and temporal ozone variations are required.

The Spectroscopy for Investigation of Characteristics of the Atmosphere of Mars (SPICAM) instrument on Mars Express has been measuring ozone abundances in the Martian atmosphere since 2003, gradually building up a global picture as the spacecraft orbits the planet.

These measurements can be complemented by ground-based observations taken at different times and probing different sites on Mars, thereby extending the spatial and temporal coverage of the SPICAM measurements. To quantitatively link the ground-based observations with those by Mars Express, coordinated campaigns are set up to obtain simultaneous measurements.

Infrared heterodyne spectroscopy, such as that provided by the Heterodyne Instrument for Planetary Wind and Composition (HIPWAC), provides the only direct access to ozone on Mars with ground-based telescopes; the very high spectral resolving power (greater than 1 million) allows Martian ozone spectral features to be resolved when they are Doppler shifted away from ozone lines of terrestrial origin.

A coordinated campaign to measure ozone in the atmosphere of Mars, using SPICAM and HIPWAC, has been ongoing since 2006. The most recent element of this campaign was a series of ground-based observations using HIPWAC on the NASA Infrared Telescope Facility (IRTF) on Mauna Kea in Hawai’i. These were obtained between 8 and 11 December 2009 by a team of astronomers led by Kelly Fast from the Planetary Systems Laboratory, at NASA’s Goddard Space Flight Center (GSFC), in the USA.

Credit: Kelly Fast

About the image: HIPWAC spectrum of Mars’ atmosphere over a location on Martian latitude 40°N; acquired on 11 December 2009 during an observation campaign with the IRTF 3 m telescope in Hawai’i. This unprocessed spectrum displays features of ozone and carbon dioxide from Mars, as well as ozone in the Earth’s atmosphere through which the observation was made. Processing techniques will model and remove the terrestrial contribution from the spectrum and determine the amount of ozone at this northern position on Mars.

The observations had been coordinated in advance with the Mars Express science operations team, to ensure overlap with ozone measurements made in this same period with SPICAM.

The main goal of the December 2009 campaign was to confirm that observations made with SPICAM (which measures the broad ozone absorption spectra feature centered at around 250 nm) and HIPWAC (which detects and measures ozone absorption features at 9.7 μm) retrieve the same total ozone abundances, despite being performed at two different parts of the electromagnetic spectrum and having different sensitivities to the ozone profile. A similar campaign in 2008, had largely validated the consistency of the ozone measurement results obtained with SPICAM and the HIPWAC instrument.

The weather conditions and the seeing were very good at the IRTF site during the December 2009 campaign, which allowed for good quality spectra to be obtained with the HIPWAC instrument.

Kelly and her colleagues gathered ozone measurements for a number of locations on Mars, both in the planet’s northern and southern hemisphere. During this four-day campaign the SPICAM observations were limited to the northern hemisphere. Several HIPWAC measurements were simultaneous with observations by SPICAM allowing a direct comparison. Other HIPWAC measurements were made close in time to SPICAM orbital passes that occurred outside of the ground-based telescope observations and will also be used for comparison.

The team also performed measurements of the ozone abundance over the Syrtis Major region, which will help to constrain photochemical models in this region.
Analysis of the data from this recent campaign is ongoing, with another follow-up campaign of coordinated HIPWAC and SPICAM observations already scheduled for March this year.

Putting the compatibility of the data from these two instruments on a firm base will support combining the ground-based infrared measurements with the SPICAM ultraviolet measurements in testing the photochemical models of the Martian atmosphere. The extended coverage obtained by combining these datasets helps to more accurately test predictions by atmospheric models.

It will also quantitatively link the SPICAM observations to longer-term measurements made with the HIPWAC instrument and its predecessor IRHS (the Infrared Heterodyne Spectrometer) that go back to 1988. This will support the study of the long-term behavior of ozone and associated chemistry in the atmosphere of Mars on a timescale longer than the current missions to Mars.

Sources: ESA, a paper published in the 15 September 2009 issue of Icarus

Posted on by Nancy Atkinson

Phoenix Phone Home! Teams Still Attempting Contact with Mars Lander

Phoenix Twilight
Phoenix at Twilight. Credit: NASA

No word yet from the Phoenix Mars Lander and, really, mission managers don’t expect to hear from the lander. But that doesn’t mean they aren’t trying. Teams are currently attempting to make contact, with another — and final — series of attempts that may occur next month.

“We haven’t heard a peep since late 2008, when a dust storm combined with the onset of winter to end the mission,” said Mark Lemmon from Texas A&M University, who worked with Phoenix’s camera. “But if Phoenix did survive, a revived mission could uncover some of the climate processes in the area around Mars’ North Pole, where most of the water seems to be.”

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Last contact with Phoenix was back in October 2008, and the teams that worked with the lander are holding out hope that some of the electronics on board survived the severe Martian winter, which dwarfs anything seen on Earth (even the Snowmageddons and Snowpocalypses). Temperatures fall to minus-180 degrees for months at a time and carbon dioxide ice likely engulfed the Phoenix lander. Still, Lemmon said he is ready to help take more pictures and analyze more data if the Lander can be restored to life.

“Phoenix accomplished its mission,” he said, “and it was never designed to survive a Martian winter. In winter, heavy amounts of carbon dioxide frost may have accumulated on its solar panels and it is possible they broke off. Without those panels, which give Phoenix its energy source, it’s pretty much powerless. In addition, other parts may have failed in the extreme cold.”

Phoenix landing site, August, 2009. Credit: NASA/JPL/U of Arizona. Annotations by Phil Stooke

The Phoenix Lander, which landed on Mars May 25, 2008, was designed to dig for soil samples and buried ice near Mars’ North Pole. It also studied Mars’ polar weather.

Phoenix returned more than 30,000 images and made several chemical analyses of the soil above the Martian permafrost. Those analyses found carbonate minerals in the soil, showed that the composition of the soil is near that of Earth’s oceans rather than being acidic, and found perchlorates, which are present in soils in Chile’s Atacama desert on Earth, where they are used as food by some species of bacteria.

Recent images from the Mars Reconnaissance Orbiter show frost in the area around Phoenix’s landing site is now dissipating. Last month, the Mars Odyssey spacecraft, which orbits the planet, made 30 attempts to contact Lander. All failed.

Lemmon says the Lander mission was a success by any measurement.

“The soil samples it dug up show several possible energy sources, such as perchlorates,” he adds, “and that discovery will have a big impact on future plans to explore Mars. The weather information Phoenix returned will be very useful in understanding Mars’ climate, and the discovery of water-ice snowfall near the end of the mission is still amazing.”

Source: Texas A&M University

Posted on by Darnell Clayton

Martian Settlers May Need Chickens To Conquer The Red Planet

If humanity ever intends upon on settling Mars (by settling I mean a one way trip with no plans on returning back to Earth), they are going to need a whole lot of chickens if they want to survive–let alone thrive–upon the red planet.

Aside from providing an excellent source of protein, chickens could help future settlers raise not only crops (such as wheat, barely, etc.) upon the barren Martian soil, but also help colonists keep the lights on through a very useful by-product (aka chicken dung).

Unlike Earth, Martian dirt is very hostile towards plant life. Unless we can genetically alter plants to grow upon the red planets soil, future settlers will have to heavily rely upon the home world for their daily bread.

Future scientists could help reduce or (even better) eliminate that need by using chicken manure, which (as far as animal dung goes) has one of the highest concentration of nutrients available, making it a perfect choice for raising plants on Mars.

But providing food for plants isn’t the only reason why future Martian colonists will probably choose these ugly (yet useful) creatures, as chicken dung can also be used for energy as well.

Using an old scientific process called pyrolysis (which is cooking biomass like manure without the presence of oxygen), future settlers could turn this smelly chicken manure into biochar (which is a charcoal like product).

Just like many farmers on Earth, future colonists could turn biochar into bio-fuel, helping to power their future  space settlements along with Martian solar panels (or an underground nuclear reactor).

While other types of animals manure could also be used for raising crop or keeping the lights on, it would be much easier (not to mention cheaper) transporting chickens en mass than larger animals.

This is mainly due to the fact than an egg (averaging about 57 grams), weigh much less than say, a baby calf (which would weigh 32 kilograms at birth), making chickens the logical choice as far as future space animals go.

Although humans may eventually import other animals to Mars (whether for food or as pets), it may not be surprising to see chickens accompany future explorers in their quest to conquer the red planet.

Image Credit: Andrei Niemimäki via Flickr

Sources: New York Times, Ezine Articles, Wise Geek

Posted on by Nancy Atkinson

Multi-Layer Mars Parfait Provides Environmental Record

This oblique view shows geological layers of rock exposed on a mound inside Gale Crater on Mars. Image credit: NASA/JPL-Caltech/University of Arizona/USGS

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Is Mars more like a Peanut Buster Parfait, a granola-yogurt parfait, –or perhaps — maybe a seven-layer salad? Near the center of a Martian crater about the size of Connecticut, hundreds of exposed rock layers form a mound as tall as the Rockies and reveal a record of major environmental changes on Mars billions of years ago. According to a new report by geologists using instruments on the Mars Reconnaissance Orbiter to look at the “parfait” of layers inside Gale Crater, the layers show that Mars was likely wet at one point, but gradually dried over time.

“Looking at the layers from the bottom to the top, from the oldest to the youngest, you see a sequence of changing rocks that resulted from changes in environmental conditions through time,” said Ralph Milliken from JPL. “This thick sequence of rocks appears to be showing different steps in the drying-out of Mars.”

Layers of rock exposed in the lower portion of a tall mound near the center of Gale Crater on Mars exhibit variations in layer thickness and range between dark and light tones. Image credit: NASA/JPL-Caltech/University of Arizona

Milliken and two co-authors of a paper in Geophysical Research Letters say that clay minerals, which form under very wet conditions, are concentrated in layers near the bottom of the Gale stack. Above that, sulfate minerals are intermixed with the clays. Sulfates form in wet conditions and can be deposited when the water in which they are dissolved evaporates. Higher still are sulfate-containing layers without detectable clays. And at the top is a thick formation of regularly spaced layers bearing no detectable water-related minerals.
Layers of rock in the upper portion of a tall mound near the center of Gale Crater on Mars exhibit a regular thickness of several meters, unlike the less regular pattern of layers in the lower formation on the same mound. Image credit: NASA/JPL-Caltech/University of Arizona

Rock exposures with compositions like various layers of the Gale stack have been mapped elsewhere on Mars, and researchers, including Jean-Pierre Bibring of the University of Paris, have proposed a Martian planetary chronology of clay-producing conditions followed by sulfate-producing conditions followed by dry conditions. However, Gale is the first location where a single series of layers has been found to contain these clues in a clearly defined sequence from older rocks to younger rocks.

“If you could stand there, you would see this beautiful formation of Martian sediments laid down in the past, a stratigraphic section that’s more than twice the height of the Grand Canyon, though not as steep,” said Bradley Thomson of the Johns Hopkins University Applied Physics Laboratory, Laurel, Md. He and John Grotzinger of the California Institute of Technology in Pasadena are Milliken’s co-authors.

NASA selected Gale Crater in 2008 as one of four finalist sites for the Mars Science Laboratory rover, Curiosity, which has a planned launch in 2011. The finalist sites all have exposures of water-related minerals, and each has attributes that distinguish it from the others. This new report is an example of how observations made for evaluating the landing-site candidates are providing valuable science results even before the rover mission launches.

Posted on by Nancy Atkinson

Movies of Spirit’s Last Moves Before Winter

Even though the Spirit rover is stuck in a Martian sandtrap, the rover drivers were actually able to move her quite a bit, and therefore improving her chances of surviving the winter. This video shows recent drives by the Spirit rover from Jan. 14 to Feb. 4, 2010 (Sols 2145 to 2165), where the center of the rover approximately 13.4 inches (34 centimeters) backwards. Since Jan 26 (sol 2157), drive commands have concentrated on placing Spirit into a favorable tilt toward the sun as the Martian winter approaches.

Posted on by Darnell Clayton

Will Bio Fuels Power Martian Colonies Instead Of Solar?

If I told you that your great, great, great grandkids would be building houses on that crimson world known as Mars, what would be the first thought to enter your head?

Rovers? Check! A comfy Martian house? Check! Power cutting rock tools? (for us guys) Double check! A bio fuel gas tank? Che–huh?!

You’re probably wondering “what power on Earth would motivate you to bring bio fuels to Mars?” The answer: a slightly altered cyanobacterium that may help us power future Martian rovers, homes–and yes–power tools with good ol’ biofuel.

The problem with settling Mars is this: despite its dazzling desert environment (if you consider frozen dry tundra’s dazzling), Mars is not the most ideal location when it comes to the energy department.

The red planet receives approximately half of the sunlight Earth does, which may dim a green geeks hope of a solar powered outpost offworld.

Worse, even if solar panels received 100% of the energy from the Sun, those big, bad global dust storms could make solar panels useless for weeks or months at a time.

The only thing “big red” has to offer future settlers is rust, dust and lots of CO2–the latter which can be converted into fuel thanks to our new best (microscopic) friend cyanobacterium.

Scientists have been studying this little creature and have found that with a “few” alterations, cyanobacterium can take CO2 (the gas that can easily kill you) and turn it into a biofuel called isobutanol.

Converted, isobutanol could help colonists power rovers, Martian settlements–and yes, even power tools (as cutting rocks with lasers is going to require lots of energy folks!) without the need to depend upon the Sun or an underground miniature nuke (which might be too expensive for small outposts).

Since bio fuels can’t openly burn in the carbon atmosphere, future rovers, houses and power tools will need to be altered to also carry oxygen as well (which we could extract from the ever abundant Martian ice).

By having an inexpensive and (hopefully) cheap fuel, establishing homes and traveling the Martian globe could become a reality without the heavy (and sometimes “helpful”) hand from governments and mega-corporations.

Image Credit: Paul Hudson via NASA

Sources: Alternative Energy News, Physorg.com

Posted on by Nancy Atkinson

Can an Immobile Spirit Rover Survive the Martian Winter?

Mission managers for the Mars Exploration Rover program announced this week that the Spirit rover will likely never rove again on Mars. But that doesn’t mean her life is over. However, with the rover virtually immobile and stuck in a sand trap, she currently is in a very vulnerable and potentially “deadly” situation as winter approaches on Mars’ southern hemisphere. Pointing the rover’s solar panels towards the sun is critical if the rover is to survive, and the rover team has just a handful of drives to make it so. And the winters are long and harsh on Mars. “The temperatures will be colder than anything Spirit has experienced before,” said John Callas, project manager for the MER mission. “This is a much more difficult and dangerous situation for Spirit, and we’re heading into a regime where vehicle is going to get colder than it ever has.”

What is Spirit facing, and what are her odds?

“Spirit will be experiencing decreasing power levels, and we will likely see energy levels that will drop below 160 watt hours,” said Callas, which is the level of power the rover needs to maintain so it can communicate daily with Earth. “If we can’t maintain that level, that will trip a low power fault where the rover shuts down or hibernates, taking the necessary steps to preserve as much power as possible. Everything is turned off except the master clock, and all the photons that hit solar arrays go into charging the batteries.”

In this low-power fault, a timer wakes the rover up occasionally to check battery levels, and if there is enough power, Spirit will wake up enough to see how charged the batteries are and attempt to communicate with Earth. “Spirit will be like a polar bear hibernating, possibly for several months, maybe on the order of 6 months that the rover will be in this state,” said Callas. “It won’t be like the Phoenix lander where it shuts down virtually completely. The rover will still be electrically active, but not with enough power to be awake each day.”

Callas predicted it will be in the March-April time frame here on Earth when they run out of ability to communicate with rover because there won’t be enough power.

Normally the rover stays warm enough simply by being “on” and running, like running your car in the winter to warm it up. But since rover will be deeply sleeping, temperatures on the rover will drop.

Callas and his team are concerned that temperatures on the rover will get very cold. Based on past winters, they expect about -40 to -50 C temperatures on Mars during the depths of winter. The electronics on the rover can withstand -40 degrees C when operating and -50 c when the rover is idle. But these standards are for a brand-new out-of-the-box rover, Callas said, not a 6 year-old rover with electronics have gone through many different temperature cycles.

Ironically, the fumaroles or steam vents that likely created the very scientifically rich “Troy” area where Spirit sits would have made it a “hot spot” on Mars. But, of course, the fumaroles are no longer active.

The rovers do have three 1-watt Radioisotope Heater Units (RHUs) which are tiny thermal heating units used to keep motors and batteries warm on the rover, so Spirit’s important insides will not get as cold as the outside.

But power from the solar panels is very important for keeping the computer and other electronics active, and right now, the position of the solar panels is not at all optimal.

“Our primary mission is to get solar panels pointed toward sun improve her chances,” said rover driver Ashley Stroupe. “Ideally the solar panels should be pointed toward the sun, to maximize the energy the rover receives. If we can get enough power to keep the rover warm, that will shorten the amount of time Spirit may have to be in a low power state.”

In upcoming drives, the team will try to get left rear wheel of the rover lifted up, by driving backward and improving its northerly tilt. Spirit is sitting in a small crater with the rim behind her, so as it moves backwards, it is slowly climbing up on the rim, tilting the rover. “On the last drive we saw 1-2 degree improvement in tilt,” Stroupe said on Tuesday. “So we’re going to do as much improvement as we can by continuing to drive backward. We can an also attempt to rotate the rover in place, so that the roll isn’t pointed as much towards the south as it is now.”

The Spirit rover's solar panels were covered with dust until a gust of wind blew it off. Credit: NASA.

Each degree of tilt towards the north gains 5 watt hours of improvement. One upside is that the solar panels are currently fairly free of dust accumulation.

When the rover attempts to wake up each day, it will be at about noon local time on Mars, when the electronics will have warmed up because of sunlight.

But there’s the possibility the team might not hear from the rover for months.

“We have to be prepared to go through a period like this,” said Callas. “We may not hear from rover, and it will be frustrating and challenging for the team, but we’ll have to be disciplined about this, and hopefully when power resumes we can resume communication in the spring.”

A look at the nearly buried wheels on the Spirit rover on Mars. Credit: NASA/JPL

And, worst case scenario, where is a very long period of time where they don’t hear from the rover, how long will the team attempt to communicate with Spirit?

“That’s a very complex problem,” Callas told Universe Today at the Tuesday’s press conference. “The rover will actually experience two levels of fault protection. The rover takes action based on hearing from Earth, and if we go too long without talking to the rover, it trips an up loss timer. We only keep about 6 weeks of communication tables on the rover, so that likely will have run out. All these things make for a complex recovery effort for the rover. It is hard to say how long we would try, because we would have to try many things before we exhaust the list of things we can do.”

Callas didn’t want to give odds if Spirit will make it through the winter. “Spirit’s best chance for survival is when we can stay in contact with her,” he said. “As long as we can maintain communication with rover we can look out for trouble, and advise her on how to best reapportion her limited resources.”

MER PI Steve Squyres said not having a roving rover is a “poignant moment” for the team. “We built the rovers to drive around, so we have shifted our focus to a different class of activities. It is a change and one we’ll have to adapt to. But this is a much better way that having an abrupt end to the mission, which would preclude doing the kind of science we’re looking forward to.” (Read more about the science Spirit can do in our earlier article)

“We have hope that Spirit will survive this cold dark winter that Spirit has ahead of her,” Squyres said.

Posted on by Nancy Atkinson

Big Full Moon and Mars Put on a Show Friday Night

An almost full Moon on Jan. 27, 2010. Credit and copyright: Alan Walters

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If your skies are clear on Friday night, January 29, 2010, take advantage of one of the skywatching highlights of the year. A full Moon and Mars will be putting on a show, and the pair will be prominently close to each other in the sky. Plus, this Friday night’s full Moon is the biggest and brightest full Moon of the year. It’s a “perigee Moon,” as much as 14% wider and 30% brighter than other full Moons you’ll see later in 2010, according to Spaceweather.com. And, even though you’ve likely not gotten an email from an excited acquaintance relaying that Mars is really close to the Earth now — that is the case. Mars is at opposition on the 29th, which means it lines up opposite the Sun and is now the closest to Earth their orbits, and so will shine brighter.

The image above of the not-quite-full Moon from January 27, 2010 is shared by Universe Today reader Alan Walters, from Florida. You can see more of his wonderful photography of the night sky, launches and shuttle landings, Florida wildlife and more at Alan Walters Photography.

Positions of the Moon and Mars. Credit: McDonald Observatory

This image, courtesy of Stardate Online and the McDonald Observatory, shows the positions of the Moon and Mars in the night sky the next few evenings.

This is not a great opposition for Mars because it occurs around the time that Earth is closest to the Sun and Mars is farthest. The gap between the two planets will be a hefty 62 million miles (99 million km). The smallest possible distance at opposition is about 35 million miles (56 million km), which happened a back in August of 2003, and prompted the infamous emails that now surface every August, that Mars would be as big the full Moon, which of course, is not — and was not — true. Mars appeared more than twice as bright then as it will this year, but was still a star-like dot in the sky.

JPL is sponsoring a Facebook Event, Friday Night With the Moon and Mars, to heighten awareness of what a great sight it will be; plus its a great way to share in the experience with others online.

And for more information, see this Science@NASA article about the close encounter.

Sources: Stardate, Spaceweather.com

Posted on by Nancy Atkinson

New Amazing Mars Flyover Videos


Doug Ellison from UnmannedSpaceflight.com has done it again… and again… and again. Here are new Mars flyover videos Doug has created from data from the HiRISE camera on the Mars Reconnaissance Orbiter. Using DEM (Digital Elevation Model)– (also known as DTM Digital Terrain Model) files provided by the HiRISE team, Doug is able to render 3-D movies of a specific location on Mars. Since he is using actual high-resolution data from HiRISE, Doug says the terrain seen in the movies has accurate vertical scaling and is not exaggerated. These new views of the Red Planet are also stunningly beautiful! The video above is of the Mojave Crater wall on Mars, and below is Athabasca Valles. And Doug says more are on the way! If you recall, Doug created the flyover video of the Spirit rover’s location that was on Astronomy Picture of the Day.
Continue reading “New Amazing Mars Flyover Videos”

Posted on by Nancy Atkinson

Could Mars Dust Be “Levitated” Away?

The Spirit rover's solar panels were covered with dust until a gust of wind blew it off in 2006. Credit: NASA.

What could potentially be the biggest problem during a human mission to Mars? One NASA study says, surprisingly, that dust could be the number one risk for both humans and equipment. Human explorers could inhale the extremely fine but rough dust particles causing severe respiratory problems, and high winds on Mars could disperse the dust to coat solar panels, penetrate through seals and interfere with machinery. But scientists at the University of Vermont may have come up with a new way to combat dust: acoustic levitation. But will it work on Mars?

The researchers conducted a feasibility study to develop an acoustic dust removing system for use in space stations or habitations on the Moon or Mars. They found a high-pitched (13.8 kHz, 128 dB) standing wave of sound emitted from a 3 cm aperture tweeter and focused on a reflector 9 cm away was strong enough to dislodge and move extremely fine (<2 µm diameter) dust particles on the reflector surface. The sound waves overcome the van der Waals adhesive force that binds dust particles to the surface, and creates enough pressure to levitate the dust, which is then blown away. The team tested the system on a solar panel coated with mock lunar and Martian dust. The output of the clean panel was 4 volts, but when coated with dust it produced only 0.4 volts. After four minutes of acoustic levitation treatment the output returned to 98.4% of the maximum. Mars dust, although fine, is rougher that Earth dust, and likely is more similar to the dust that covers the Moon. The thin atmosphere on Mars means dust particles are not as rounded as they would be on Earth and can remain quite sharp and abrasive. [/caption] Mars dust, as we have found with the Mars rovers, has a high electrostatic charge, which means the fine dust clings to everything. The dust has severely decreased the efficiency of solar panels on the rovers, and over time has likely caused other problems with the mechanical operation on the rovers as well. We've had several articles here on Universe Today discussing the problems of dust on the solar panels of the Mars Exploration Rovers, and inevitably we get comments from readers suggesting "wiper blades" or other types of cleaning solutions for the solar panels. Amazingly, Mars itself has cleaned the rovers' solar panels several times with gusts of wind from the almost ubiquitous Martian dust devils. Acoustic levitation could be a solution, as it would be cheap and easily built. But there is a problem, and it is a big one: it will only work when it is sealed inside a space station or other habitation. It will not work where there is no atmosphere (such as the moon) or where the atmosphere is low pressure and thin (such as Mars) because sound is a pressure wave that travels through the air. So, we might be stuck with having to resort to wiper blades, or devising a way to mimic the dust devils and gusts of wind that have repeatedly benefited the Mars rovers. Unless we can figure out a way to get dust to levitate without sound. Nirvana anyone? Source: PhysOrg