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”
Could Mars Dust Be “Levitated” Away?
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.
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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
Debunking Astrology: Mars Can’t Influence You
So you think the position of Mars in the sky at the time of your birth made you tall, dark, and handsome (or short, fair, and ugly)? Or lucky (or unlucky) in love? If you think believing in astrology is anywhere close to scientific, well, Dude, time to think again.
Pick two babies born within a minute of each other. One has two nurses and a doctor attending; the other, just a midwife. One is born in a brightly lit maternity ward in a downtown big city hospital; the other in a poorly lit room in a village 50 kilometers from the nearest big city. ‘Downtown’ is just a few meters above sea level; the village is situated on a 1000 meter high plateau. These local differences have far greater effects on the babies than Mars does. Let’s see how.
Nearly five centuries of physics have given us quite a few certainties, and among those are that the only long range forces in the universe are gravity and electromagnetism. And both of these, from Mars, are totally – and I mean totally – overwhelmed by those same forces that were produced by things near you when you were delivered. In a word, Mars can’t influence you.
Start with gravitation.
The gravitational force between you and Mars is greatest when Mars is closest to the Earth; let’s say that’s 56 million kilometers. Now Mars has a mass of 6.4 x 1023 kg, so the acceleration, here on Earth, due to Martian gravity would be 1.4 x 10-8 meters per second per second (m s-2).
How did I work that out? By using Newton’s law of universal gravitation:
F = Gm1m2/r2
and:
F = ma
so:
a = GmMars/distance-to-Mars2.
How does this compare with variations in gravitational force due to adults standing nearby (everyone has a mother, so we won’t count her)?
Let’s take 60 kg as an adult’s mass, and a distance of 1 meter; that gives a gravitational acceleration of 4 x 10-9 m s-2, so just three adults nearby would have the same gravitational effect on you as Mars!
How does this compare with variations in gravitational force we know people born at the same time – but elsewhere on Earth – experienced?
Let’s take a difference in altitude of 1000 m (lots of big cities have altitudes greater than this – Mexico City, for example, is at 2240 m – and lots are close to sea level), and calculate the difference in acceleration due to the Earth’s gravity (this ignores several important factors, such as the Earth’s rotation, and local differences in g). Well, it works out as 0.003 m s-2, or about 200,000 times greater than Martian gravity!
In fact, if you were born just half a centimeter higher, you’d be influenced to the same extent, gravitationally, as by Mars!
Next, electromagnetism.
You can be influenced, electromagnetically, in four separate ways: by a magnetic field, by an electric current, by an electric field, and by electromagnetic radiation. How powerful is Mars, electromagnetically?
There’s no electric current between Mars and Earth; the solar wind – which blows outward from the Sun (so Mars is ‘downstream’, and any electromagnetic influence carried by the solar wind would be from Earth to Mars) – is neutral, on balance, and carries no current.
The solar wind is a plasma, and any electric field there is in it will not be felt much more than a few Debye lengths’ away (basically, because electrons and ions are free to move in a plasma, they screen charges – the source of electric fields – quite effectively; the Debye length is about as far as an electric field can penetrate). Now the solar wind can be quite dynamic – meaning it can change a lot – but the Debye length in any part of it will rarely, if ever, be greater than a few tens of meters. Let’s be generous and say an electric field could be felt up to a kilometer away. But Mars never comes closer to the Earth than ~50 million km!
Well, that makes any electric field influence from Mars impossible, doesn’t it?!
While Mars does have a weak magnetic field, it has no influence on Earth, because the Earth’s own field creates a magnetosphere around us, one that screens out external magnetic fields. Besides, as Mars is downstream from us (the way the solar wind blows), and as the solar wind can carry (actually stretch) a magnetosphere only in the direction it blows, any magnetic influence would be from Earth to Mars, not Mars to Earth.
Three down, one to go.
The Earth’s atmosphere blocks all electromagnetic radiation except for that which we see by (and a bit on the UV side too), some infrared, and in the microwave and radio regions of the electromagnetic spectrum.
Mars is a very weak source of microwaves and radio waves, and even in the (radio) quietest places on Earth, electromagnetic radiation from (distant) radio stations, (distant) cellphone towers, TV satellites, airplanes overhead, etc totally, totally drowns out any Martian signals.
On a clear, moonless night, Mars may seem bright to your dark-adjusted eyes … but most likely you were born under quite bright lights, and indoors. No Martian influence here either.
So what do we have then?
Like I said, Mars can’t make you tall dark and handsome, nor can it influence your love life.
No More Roving for Spirit; Stationary Science Ahead
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The Spirit rover’s driving days are likely over, as efforts to extricate the rover have been curtailed. “We do not believe that Spirit is extractable,” said Doug McCuistion, director of NASA’s Mars Exploration Program. But mission managers stressed that today is not a day of loss at this point, as they hope to continue to make some exciting scientific observations. However, the rover needs to be tilted to gather as much sunlight as possible in order to survive the Martian winter. John Callas, project manager for the MER mission told Universe Today at today’s press briefing that time is short. “We estimate about three weeks of driving activity, and we can’t drive every day,” he said. “So there are just a handful of drives left before there is insufficient power to continue.”
Callas added that around the March-April time frame will be the last images and data the rover can transmit before going into hibernation for the winter.
Spirit has been embedded in a sandtrap for 10 months, and the rover team has been engaged in an ambitious process to extricate the rover. They’ve encountered numerous setbacks, including the loss of use of an additional wheel, making it a four-wheeled rover. (Spirit’s right front wheel has not worked for a couple of years, now the right rear wheel has lost functionality).
“Spirit is in a golfer’s worst nightmare, stuck in a sand trap that no matter how many strokes you take you can’t get out of,” said McCuistion.
Pointing the rover’s solar panels towards the sun is critical if the rover is to survive. In past winters, the movable rover has been able to be positioned to allow for maximum sun-gathering but the current embedding of the rover has left it with an unfavorable tilt, 9 degrees to south, when they really want a level rover — or even better — tilted to north.
Rover driver Ashley Stroupe said the rover is now pitched flat and rolled to left. “We want to try to pitch it forward and roll right for best winter survival.”
The last few drives were aimed at trying to improve the rover’s position, and were mildly successful.
“We’ve aimed toward improving northerly tilt,” said Stroupe. “Spirit is sitting in a small crater with the rim behind her, so as it moves backwards, it is slowly climbing up, providing more tilt. On the last drive saw 1-2 degree improvement in tilt.”
In recent drives, the rover has moved approximately 20 centimeters. The team can also attempt to rotate the rover in place, so that the roll isn’t pointed as much towards the south as it currently is.
Should they be successful, and if the rover survives the winter, the science team has some exciting prospects of continuing science with Spirit.
“We have hope that Spirit will survive this cold dark winter that she has ahead of her,” said MER principal investigator Steve Squyres. “The bottom line is we’re not giving up on Spirit.”
Squyres said they are most excited about tracking the radio signal from Spirit in order to determine if Mars has a solid or liquid core. “This is something totally new, something we’ve never done,” Squyres said. “If we can accurately determine the rover’s motion in space in three dimensions, we can see the motions of Mars in orbit and track it precisely, then we can characterize the wobble very precisely. The way Mars wobbles depends on its internal structure. If Mars has a solid core of iron, will wobble one way but if it has a liquid molten core it will wobble another way. We should be able to do this by tracking the stationary rover for six months.”
Squyres said the team is finding new tricks on how to use a stationary rover. Additionally, they should be able to characterize the odd soil at the Home Plate region, and characterize the interactions between the atmosphere and the surface of Mars.
“We’re not giving up on Spirit and we’ll keep squeezing as much science out of the rover as we can,” Squyres said. “We feel there is a lot of really exiting science yet ahead.”
Source: Press briefing
No Word Yet From Phoenix; Spirit’s Days May be Numbered
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Not a peep yet from the Phoenix lander. The Mars Odyssey orbiter has completed all 30 relay overflights of the Phoenix landing site that were scheduled for Jan. 18 to 21, and heard nothing from the lander. Additional listening campaigns will be conducted in February and March. NASA has said repeatedly that hearing from the lander would be highly unlikely, as Phoenix was never designed to withstand the Martian arctic winters.
Meanwhile, the outlook isn’t brilliant for the Spirit rover, either.
Efforts to free the rover have barely budged it, and as the Martian autumn approaches, precious sunlight which provides power to the rover is declining each day. As of now, Spirit is tilted the wrong way to generate enough heat to make it through the winter, although the Free Spirit team is working to change the angle of her solar panels.
The rover team has now begun driving Spirit backward as the next technique for attempting to extricate the rover from the sand trap where it is embedded. The first two backward drives produced about 6.5 centimeters (2.6 inches) of horizontal motion and lifted the rover slightly.
However, the right-rear wheel is still non-functional, along with the right-front wheel (even though that wheel came back to life, briefly), and during a recent extrication drive attempt, the left middle wheel stalled. The team is working to get more diagnostic information about that wheel stall. Even with four working wheels, Spirit would have a very difficult path to get out of her predicament.
And rover fans must be continuing to suggest using the rover’s robotic arm to help push Spirit out, because the latest press release about Spirit included some back-of-the-envelope calculations about using the arm for just such an action. They figured out that by pushing with the arm, only about 30 newtons of lateral force could be achieved, while a minimum of several hundreds of newtons would be needed to move the rover. Further, such a technique risks damaging the arm and preventing its use for high-priority science from a stationary rover. The other technique of re-sculpting the terrain and perhaps pushing a rock in front of or behind the left-front wheel was also assessed to be of little to no help and, again, risks the arm. There is also a large risk of accidentally pushing the rock into the open wheel and jamming it.
When asked if he was discouraged about Spirit’s current situation, NASA’s lead scientist for the Mars exploration program, Michael Meyer said, “You gotta be joyful when something that was only supposed to operate for three months lasts over 6 years.”
The Opportunity rover, on the other side of Mars, continues her approximately 7 mile trek to Endeavour Crater. The rover left the rock called Marquette Island on Sol 2122 (Jan. 12, 2010), and has now crossed the 19-kilometer (11.8-mile) odometer mark. Amazing!
There is a relatively fresh impact crater that has been named “Conception,” and Oppy will stop to investigate, having to detour about 250 meters (820 feet) to the south.
Sources: JPL, NASA TV
HiRISE Makes Your Wishes Comes True
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The HiRISE science team is now taking requests! A new web tool called HiWish is now available for the high-resolution camera on the Mars Reconnaissance Orbiter which allows the public to suggest a location on Mars where the HiRISE instrument should take an image. If you don’t have a particular location, you can use the HiWish site to browse around the planet, examine the locations of other data sets, and find a place that should be imaged. The team will then put into their targeting database, and your suggestion may get selected as an upcoming observation. Furthermore, the HiWish site allows you to track your suggestions and be notified when one of your suggestions gets taken.
Maybe you could even find a really unusual feature on Mars, such as this race-track-like feature that may one day be a landing site for a future mission to the Red Planet. HiRISE images will help determine if this spot is sufficiently safe for landing, such as not too many boulders, steep slopes, or too many high speed MASCAR races — (that’s the Mars Association for Super Cool Aerodynamical Racing). If it is safe, it may be considered for the 2011 Mars Science Laboratory or the 2018 rovers that ESA and NASA are working on for a join mission.
The above image is actually a huge shield volcano in the northeast part of Syrtis Major, and near the Northwest rim of Isidis Planitia, a giant impact basin.
So, go create an account at HiWish and get wishing!
Stunning New Views From HiRISE; Plus Big Announcement?
Caption: Dune symmetry on Mars. Credit: NASA/JPL/University of Arizona
It is so wonderful to see the Mars Reconnaissance Orbiter back in action, especially our favorite camera, the High-Resolution Imaging Science Experiment, or HiRISE. The HiRISE team released some of their latest images this week, and they are particularly stunning, including this one of symmetrical dunes in a small crater in Noachis Terra, west of the giant Hellas impact basin. Alfred McEwan, from the HiRISE team and the University of Arizona says the dunes here are linear, and are thought to be created due to shifting wind directions. In places, each dune is remarkably similar to adjacent dunes. The linear dune fields on Mars are similar to the ones seen on Titan, although not quite as large. The debris between the dunes are large boulders.
More images below, but on another note, HiRISE Twitter notes there will be a “big announcement” on Wednesday, January 20. A major discovery? Mission extension? Website redesign? Stay tuned.
This jaw-dropping beauty accompanied a press release announcing that 21 articles from HiRISE made up the entire contents of a special January issue of the journal Icarus . The papers analyzed Martian landforms shaped by winds, water, lava flow, seasonal icing and more.
This view shows color variations in bright layered deposits on a plateau near Juventae Chasma in the Valles Marineris region of Mars.
This almost looks like etchings on Mars’ surface, and they are very strange landforms indeed. McEwan notes that materials appear to have flowed in a viscous manner, like ice, here on the floor of Hellas Basin. Viscous flow features are common over the middle latitudes of Mars, but those in Hellas are especially unique, for unknown reasons.
This is a beautiful shot of frost covered dunes inside a crater. The HiRISE team says that on the floor of this crater where there are no dunes, the ice forms an uninterrupted layer. On the dunes however, dark streaks form as surface material from below the ice is mobilized and deposited on top of the ice. In some cases this mobile material probably slides down the steep face of the dune, while in other cases it may be literally blown out in a process of gas release similar to removing a cork from a champagne bottle.
Recent impact crater. Credit: NASA/JPL/University of Arizona
This impact crater could be relatively new, as it does not appear in images taken by the Viking Orbiters in 1976. McEwan said the HiRISE team suspects that the crater is more than several decades old, however, “because at full resolution we see a textured surface that is common in dust-mantled regions of Mars, but absent in the youngest craters.” While it could have been created recently, the other explanation is that there may have been more dust on the surface in 1976 or the air may have been hazy, obscuring the crater.
Click on each of the images for access to the higher resolution versions, or go directly to the HiRISE website.
Odyssey to Start Listening for Phoenix Lander
Caption: The Phoenix Mars Lander, its backshell and its heatshield are visible within this enhanced-color image of the Phoenix landing site taken on Jan. 6, 2010 by the High Resolution Imaging Science Experiment (HiRISE) camera on NASA’s Mars Reconnaissance Orbiter. Image credit: NASA/JPL-Caltech/University of Arizona
Listen up, all you Phoenix lander fans! Beginning Jan. 18, the Mars Odyssey orbiter will start listening for any signs of life from Phoenix, which has been sitting silently on the frozen arctic region of Mars since its last communication in November 2008. The Phoenix team says hearing any radio transmission from the lander is high improbably, but possible. Never say never….
“We do not expect Phoenix to have survived, and therefore do not expect to hear from it. However, if Phoenix is transmitting, Odyssey will hear it,” said Chad Edwards, chief telecommunications engineer for the Mars Exploration Program at NASA’s Jet Propulsion Laboratory, Pasadena, Calif. “We will perform a sufficient number of Odyssey contact attempts that if we don’t detect a transmission from Phoenix, we can have a high degree of confidence that the lander is not active.”
Odyssey will pass over the Phoenix landing site approximately 10 times each day during three consecutive days of listening this month and two longer listening campaigns in February and March. The listening attempts will continue until after the sun is above the horizon for the full 24.7 hours of the Martian day at the lander’s high-latitude site. During the later attempts in February or March, Odyssey will transmit radio signals that could potentially be heard by Phoenix, as well as passively listening.
In the extremely unlikely case that Phoenix survived the winter, it is expected to follow instructions programmed on its computer. If systems still operate, once its solar panels generate enough electricity to establish a positive energy balance, the lander would periodically try to communicate with any available Mars relay orbiters in an attempt to reestablish contact with Earth. During each communications attempt, the lander would alternately use each of its two radios and each of its two antennas.
If Odyssey does hear from Phoenix, the orbiter will attempt to lock onto the signal and gain information about the lander’s status. The initial task would be to determine what capabilities Phoenix retains, information that NASA would consider in decisions about any further steps.
Phoenix landed in May, 2008 and worked for about five months before succumbing to the cold weather. Since then, Phoenix’s landing site has gone through autumn, winter and part of spring. The lander’s hardware was not designed to survive the temperature extremes and ice-coating load of an arctic Martian winter.
But who knows; our Mars spacecraft seemingly have a tendency to surprise us…
Source: JPL
New Year’s Resolution: Find the Mars Polar Lander
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Finding hidden treasure would be a great way to start the new year, don’t you think? And somewhere in this patterned landscape the remains of a missing spacecraft could be hidden, just waiting to be found. The Mars Polar Lander arrived at the Red Planet 10 years ago in December of 1999, but just before the lander entered the Martian atmosphere, MPL went silent. An immediate search began for the remains of the MPL using images from Mars Global Surveyor, and now the HiRISE camera on the Mars Reconnaissance Orbiter is continuing the search with high resolution images of the area in which MPL is most likely to have landed. The image here is another image in a series of images from HiRISE to look for MPL.
Investigations propose the most likely cause of the mission failure is that the spacecraft’s computers misinterpreted the release of the lander’s legs in preparation for descent as touch-down on the Martian surface, causing descent engines to shut off when the lander was still 40 meters (130 feet) above ground. However, no one knows for sure.
Find higher resolution images of this region here. See our previous articles about finding MPL — with additional images — here, and here.
See this page from the HiRISE site for a links to all the images. On this page, you’ll find an overview of the Mars Polar Lander, its disappearance, the search to find it, and why they want to find it. Emily also has a lengthy post with tips and instructions on how to search for particular objects in the HiRISE images. If you think you have found something of interest, post a comment on this page of the HiRISE Blog, or use this form to contact the HiRISE team. The UnmannedSpaceflight website has a thread discussing the search (serious searchers only).
Good luck!
Will the Spirit Rover Survive 2010?
In just a few days, the Spirit rover will celebrate six incredible years on Mars. But JPL put out a press release today, as well as the video above, saying the outlook for Spirit’s survival is not good. Being stuck in a sand trap with wheels that aren’t working well are challenges to Spirit’s mobility that could prevent the rover team from using a key survival strategy — positioning the rover’s solar panels to tilt toward the sun to collect power for heat to survive the severe Martian winter. “The highest priority for this mission right now is to stay mobile, if that’s possible,” said Steve Squyres, principal investigator for the rovers.
I’m still holding out hope, however, that the rover team will work another miracle, and that 2010 will be another happy year for Spirit on Mars — see the image below created by Stu Atkinson.
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But if mobility is not possible, the next priority is survival. To to that, the rover team will attempt to improve the rover’s tilt, while Spirit is able to generate enough electricity to turn its wheels. Spirit is in the southern hemisphere of Mars, where it is autumn, and the amount of daily sunshine available for the solar-powered rover is declining. This could result in ceasing extraction activities as early as January, depending on the amount of remaining power. Spirit’s tilt, nearly five degrees toward the south, is unfavorable because the winter sun crosses low in the northern sky.
Unless the tilt can be improved or luck with winds affects the gradual buildup of dust on the solar panels, the amount of sunshine available will continue to decline until May 2010. During May, or perhaps earlier, Spirit may not have enough power to remain in operation.
“At the current rate of dust accumulation, solar arrays at zero tilt would provide barely enough energy to run the survival heaters through the Mars winter solstice,” said Jennifer Herman, a rover power engineer at NASA’s Jet Propulsion Laboratory in Pasadena, Calif.
The team is evaluating strategies for improving the tilt even if Spirit cannot escape the sand trap, such as trying to dig in deeper with the wheels on the north side. In February, NASA will assess Mars missions, including Spirit, for their potential science versus costs to determine how to distribute limited resources. Meanwhile, the team is planning additional research about what a stationary Spirit could accomplish as power wanes.
“Spirit could continue significant research right where it is,” said Ray Arvidson of Washington University in St. Louis, deputy principal investigator for the rovers. “We can study the interior of Mars, monitor the weather and continue examining the interesting deposits uncovered by Spirit’s wheels.”
A study of the planet’s interior would use radio transmissions to measure wobble of the planet’s axis of rotation, which is not feasible with a mobile rover. That experiment and others might provide more and different findings from a mission that has already far exceeded expectations.
Source: JPL