Mars Archives

December 11, 2008December 24, 2015 by Ian O'Neill

Time Magazine Top 10 Scientific Discoveries of 2008: Space and Physics Dominate

Direct observation of an exoplanet orbiting the star Fomalhaut - Number 6 in the top 10 (NASA/HST)

[/caption]2008 has been an astounding year of scientific discovery. To celebrate this fact, Time Magazine has listed the “Top 10 Scientific Discoveries” where space exploration and physics dominate. Other disciplines are also listed; including zoology, microbiology, technology and biochemistry, but the number 1 slot goes to the most ambitious physics experiment of our time. Can you guess what it is? Also, of all our endeavours in space, can you pick out three that Time Magazine has singled out as being the most important?

As we approach the end of the year, ready to welcome in 2009, it is good to take stock and celebrate the mind-blowing achievements mankind has accomplished. Read on for the top 10 scientific discoveries of 2008…

The best thing about writing for a leading space news blog is that you gain wonderful overview to all our endeavours in astronomy, space flight, physics, politics (yes, space exploration has everything to do with politics), space commercialization and science in general. 2008 has been such a rich year for space exploration; we’ve landed probes on other worlds, studied other worlds orbiting distant stars, peered deep into the quantum world, learnt profound things about our own planet, developed cutting-edge instrumentation and redefined the human existence in the cosmos. We might not have all the answers (in fact, I think we are only just beginning to scratch the surface of our understanding of the Universe), but we have embarked on an enlightening journey on which we hope to build strong foundations for the next year of scientific discovery.

In an effort to assemble some of the most profound scientific endeavours of this year, Time Magazine has somehow narrowed the focus down to just 10 discoveries. Out of the ten, four are space and physics related, so here they are:

6. Brave New Worlds: First direct observations of exoplanets

Infrared observations of a multi-exoplanet star system HR 8799 (Keck Observatory)

In November, we saw a flood of images of alien worlds orbiting distant stars. On the same day, Hubble publicised strikingly sharp images of an exoplanet orbiting a star called Fomalhaut (pictured top) and then a ground-based Keck-Gemini campaign made the first direct observations of a multi-exoplanet system around a star called HR8799 (pictured left). A few days later, yet another image came in from another research group at the European Southern Observatory, spotting the very compact orbit of an exoplanet around the star Beta Pictorus.

Considering there have never been any direct observations of exoplanets before November 2008–although we have known about the presence of worlds orbiting other stars for many years via indirect methods–this has been a revolutionary year for exoplanet hunters.

4. China Soars into Space: First taikonaut carries out successful spacewalk

Zhai Zhigang exits the Shenzhou-7 capsule with Earth overhead (Xinhua/BBC)

Following hot on the heels of one of the biggest Olympic Games in Beijing, China launched a three-man crew into space to make history. The taikonauts inside Shenzhou-7 were blasted into space by a Long March II-F rocket on September 25th.

Despite early controversy surrounding recorded spaceship transmissions before the rocket had even launched, and then the sustained efforts by conspiracy theorists to convince the world that the whole thing was staged, mission commander Zhai Zhigang did indeed become the first ever Chinese citizen to carry out a spacewalk. Zhai spent 16 minutes outside of the capsule, attached by an umbilical cable, to triumphantly wave the Chinese flag and retrieve a test sample of solid lubricant attached to the outside of the module. His crew mate Liu Boming was also able to do some spacewalking.

Probably the most incredible thing about the first Chinese spacewalk wasn’t necessarily the spacewalk itself, it was the speed at which China managed to achieve this goal in such a short space of time. The first one-man mission into space was in 2003, the second in 2005, and the third was this year. Getting man into space is no easy task, to build an entire manned program in such a short space of time, from the ground-up, is an outstanding achievement.

2. The North Pole – of Mars: The Phoenix Mars Lander

Capturing the world's attention: Phoenix (NASA/UA)

Phoenix studied the surface of the Red Planet for five months. It was intended to only last for three. In that time, this robotic explorer captured the hearts and minds of the world; everybody seemed to be talking about the daily trials and tribulations of this highly successful mission. Perhaps it was because of the constant news updates via the University of Arizona website, or the rapid micro-blogging via Twitter; whatever the reason, Phoenix was a short-lived space celebrity.

During the few weeks on Mars, Phoenix discovered water, studied atmospheric phenomena, plus it characterized the regolith to find it is more “soil-like” than we gave it credit for. However, Phoenix also discovered a chemical called perchlorate that could be hazardous to life on the Martian surface, but there is a flip-side to that coin; the chemical may provide energy for basic forms of life.

Like all good adventures there were twists and turns in Phoenix’s progress, with the odd conspiracy thrown in for good measure. Even during Phoenix’s sad, slow death, the lander had some surprises in store before it slowly slipped into a Sun-deprived, low energy coma.

To give the highly communicative lander the last word, MarsPhoenix on Twitter has recently announced: “Look who made Time Mag’s Top 10 list for Scientific Discoveries in 2008: http://tinyurl.com/5mwt2l”

1. Large Hadron Collider

The complexity of the Large Hadron Collider (CERN/LHC/GridPP)

Speaking of “capturing the hearts and minds” of the world, the Large Hadron Collider (LHC) has done just that, but not always in a positive way (although common sense seems to be winning). So, in the #1 spot of Time Magazine’s Top 10 Scientific Discoveries of 2008, the LHC is a clear winner.

In the run-up to the switch-on of the LHC in September, the world’s media focused its attention on the grandest physics experiment ever constructed. The LHC will ultimately probe deep into the world of subatomic particles to help to explain some of the fundamental questions of our Universe. Primarily, the LHC has been designed to hunt for the elusive Higgs boson, but the quest will influence many facets of science. From designing an ultra-fast method of data transmission to unfolding the theoretical microscopic dimensions curled up in space-time, the LHC is a diverse science, with applications we won’t fully appreciate for many years.

Unfortunately, as you may be wondering, the LHC hasn’t actually discovered anything yet, but the high-energy collisions of protons and other, larger subatomic particles, will revolutionize physics. I’d argue that the simple fact the multi-billion euro machine has been built is a discovery of how advanced our technological ability is becoming.

Although the first particles were circulated on that historic day on September 10th, we’ll have to wait for the first particle collisions to occur some time in the summer of 2009. Engineers are currently working hard to repair the estimated £14 million (~$20 million) damage caused by the “quench” that knocked out a number of superconducting electromagnets on September 19th.

For more, check out the Top 10 Scientific Discoveries in Time Magazine, there’s another six that aren’t related to space or physics

December 10, 2008March 3, 2023 by Nancy Atkinson

HiRISE Wows Again, This Time in 3-D

Arabia Terra in 3-D. Credit: NASA/JPL/UA

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Grab your 3-D glasses and prepare to be amazed (and addicted!) The team from the remarkable HiRISE Camera on board the Mars Reconnaissance Orbiter has released a collection of 3-D images — 362 of ’em — of Mars surface. The incredible power of this camera can resolve features as small as one meter, or 40 inches, across, and in looking at these 3-D images, it’s almost like being there. Above is one of my favorites from this collection, Arabia Terra. “It’s really remarkable to see Martian rocks and features on the scale of a person in 3-D,” said Alfred McEwen of UA’s Lunar and Planetary Laboratory, HiRISE principal investigator. “The level of detail is just much, much greater than anything previously seen from orbit.”

How was the team able to create so many 3-D images? And how can you get or make a pair of 3-D glasses?

Usually, creating 3-D anaglyphs is a tedious and time-consuming process. But the HiRISE team was able to automate some of the software used in processing the images so two images of a stereo pair could be fed into the software “pipeline” and correlated automatically. So look for even more 3-D images in the future. But 362 should keep most of us busy, for awhile anyway!

Here, spectacular layers are exposed on the floor of a large canyon in the Valles Marineris system called Candor Chasma which is about 2-and-a-half miles, or 4 kilometers deep. The canyon may once have been filled to its rim by sedimentary layers of sand and dust-sized particles, but these have since eroded, leaving patterns of elongated hills and layered terrain that has been turned and folded in many angles and directions.

If you don’t have a pair of 3-D glasses, here’s a link to a list of several sources of finding some, or you can even make your own. Sometimes, 3-D glasses can be found for free on cereal boxes, or in children’s books or other sources.

Find out how 3-D images are made, and learn how to make your own 3-D images here.

Here is a 3-D version of Becquerel Crater, and the layered terrain of which we wrote about last week, which was formed by cyclical climate change.

See the entire collection of HiRISE 3-D’s here.

Source: U of Arizona

December 6, 2008April 26, 2016 by Nancy Atkinson

“Stairways” on Mars Lead to Clues on Cyclical, Moderate Climate

Rhythmic bedding in sedimentary bedrock within Becquerel crater on Mars is suggested by the patterns in this image from NASA's Mars Reconnaissance Orbiter. Image credit: Image credit: NASA/JPL-Caltech/University of Arizona

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We see evidence on Mars’ surface of a violent past: massive volcanic eruptions, catastrophic floods, and a surface scarred with craters. But new images of rock formations on Mars resembling stairs suggest Mars at one time had a regular pattern of predictable and even moderate climate cycles persisting for millions of years. Three-dimensional images from the HiRISE camera on the Mars Reconnaissance Orbiter show patterns in thick stacks of sedimentary rock layers, formed by a cyclical climate that is likely tied to the wobble of Mars on its axis.

Combining several images of the rock formations from different perspectives, scientists were able to produce three dimensional images, as well as a dramatic flyby movie of the layered sediments. Based on a pattern of layers within layers found at an area called Becquerel crater, the scientists propose that each layer was formed over a period of about 100,000 years and that these layers were produced by cyclical climate changes. The outcrops have been eroded into mounds on the floors of the craters, with many of the layered deposits showing a stair-stepped shape. Each layer has exactly the same thickness.

Sequences of cyclic sedimentary rock layers exposed in an unnamed crater in Arabia Terra, Mars. (Credit, both images: Topography, Caltech; HiRISE Images, NASA/JPL/University of Arizona)

Every 10 of the “staircase” layers are bundled into a larger unit, which the team, led by Kevin Lewis of the California Institute of Technology, calculates was laid down over a million-year period, and Becquerel contains 10 of these bundles. One million years is the same duration as the periodic variations in Mars’ tilt, suggesting that climate variations induced by the tilt produced the layering. Each bundle, then, represents climate processes as the planet tilted. This tilt periodically cooled the equatorial region and warmed the poles as they received more sunlight.

“Due to the scale of the layers, small variations in Mars’s orbit are the best candidate for the implied climate changes,” said Kevin Lewis of the California Institute of Technology, who led the study. “These are the very same changes that have been shown to set the pacing of ice ages on the Earth and can also lead to cyclic layering of sediments.”

This image shows sedimentary-rock layering in which a series of layers are all approximately the same thickness. Image credit: NASA/JPL-Caltech/University of Arizona

The tilt of Earth on its axis varies between 22.1 and 24.5 degrees over a 41,000-year period. The tilt itself is responsible for seasonal variation in climate, because the portion of the Earth that is tipped toward the sun–and that receives more sunlight hours during a day–gradually changes throughout the year. During phases of lower obliquity, polar regions are less subject to seasonal variations, leading to periods of glaciation.

Mars’s tilt varies by tens of degrees over a 100,000-year cycle, producing even more dramatic variation. When the obliquity is low, the poles are the coldest places on the planet, while the sun is located near the equator all the time. This could cause volatiles in the atmosphere, like water and carbon dioxide, to migrate poleward, where they’d be locked up as ice.

“It’s easy to be fooled without knowing the topography and measuring the layers in three dimensions,” said Alfred McEwen of the University of Arizona, Tucson, principal investigator for the camera and a co-author of the paper. “With the stereo information, it is clear there’s a repeating pattern to these layers.”

Sources: JPL, Caltech

December 4, 2008December 24, 2015 by Nancy Atkinson

Mars Science Laboratory Mission Delayed Two Years

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NASA’s Mars Science Laboratory has been delayed for two years and will now launch in the fall of 2011. The decision to delay is based on various technical problems the MSL team has encountered and having enough time to work through the problems, as well as provide adequate time for testing all the systems on the car-sized rover. The main problems are the actuators, the gear boxes for all the moving parts. Mars program manager Doug McCuistion said the team is actually only a few months behind schedule, but in going to Mars, that doesn’t matter since a launch window to the Red Planet only comes once every 26 months. “We know these actuator motors must work on Mars and we’ve got anomalies on some of them we don’t understand,” said McCuistion. “It’s the right thing to delay the mission to take the appropriate time to understand the technical issues and test everything thoroughly.”

“Failure is not an option for this mission,” said Ed Weiler, NASA’s associate administrator for science.

The MSL mission will send a next-generation rover with unprecedented research tools to study the early environmental history of Mar, with the fundamental purpose to explore if the conditions for microbial life on Mars ever existed, or if they exist now.

The slip to 2011 will cost $400 million, making the total cost the mission about 2.2-2.3 billion in life cycle costs.

Weiler said there will some “pain” in planetary science and other Mars missions, but there will be paybacks, and no cancelations of any missions or programs are expected. There could be subsequent delays in other missions, however.

“There’s nobody who would like to launch in 2009 more than this team,” said JPL Director Charles Elachi. “These are the same people who put the face of NASA on the front page of newspapers the past few years with our other Mars missions. Unfortunately despite full support by NASA headquarters and the contractors, we just came a little short on time. The plan is to understand these technical issues, look for solution and do a very comprehensive test program. You can’t rely on luck to be successful on Mars.”

The vast majority of the hardware for the rover has been completed, but not everything is working well, particularly the actuators. NASA officials at today’s press conference all said they can’t send MSL to Mars without knowing everything they can about the issues with the actuators.

“The actuators are basically motors in a gear box,” said McCuistion. “All our landers have robotic actuators, and they enable the rover to do what they do: to drive and stop, they run the elbow and wrist join for the robotic arm and drills in sample handling devices. That’s why they are absolutely crucial to these missions. If the actuators can’t move, we essentially have junk on the surface of Mars.”

There are 31 different actuators on MSL, and 60 flight actuators and 45 engineering actuators are being built. Some of the problems have come from the manufacturing side with workmanship, and the most recent issue is drag torque issues within the devices. “The criticality and the number of these actuators is key,” said Elachi. “These actuators are much more massive than for MER mission since the MSL rover is about 8 times bigger, and they are very sophisticated.”

When asked if NASA had considered canceling the MSL mission, Griffin said absolutely not. “Before canceling I’d have to believe the project is going badly in a technical sense, but it’s not. When you’re doing things that have never been done before, you’re likely to encounter unforeseen difficulties. But just having difficulties is no cause to cancel. We had problems with Hubble, and we had problems with COBE, but I don’t think today anyone regrets having Nobel prize winning science from these missions. Unless you’re interested in building cookie cutter copies of previous spacecraft, and nobody is interested in doing that, you’ll encounter problems with hardware that’s never been built before.”

Source: NASA TV

December 1, 2008December 24, 2015 by Nancy Atkinson

Who Listens For Phoenix?

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Phoenix isn’t merely dead; it’s really most sincerely dead. NASA has now stopped listening for any residual beeps sent by the Phoenix lander with the spacecraft orbiting Mars. After nearly a month of daily checks to listen for any last communications from the lander, the Mars Odyssey and the Mars Reconnaissance Orbiter have ended their efforts to listen for Phoenix. The final communication from Phoenix remains a brief signal received via Odyssey on Nov. 2. “The variability of the Martian weather was a contributing factor to our loss of communications, and we were hoping that another variation in weather might give us an opportunity to contact the lander again,” said Phoenix Mission Manager Chris Lewicki of NASA’s Jet Propulsion Laboratory.

The last attempt to listen for a signal from Phoenix was when Odyssey passed overhead at 3:49 p.m. PST Saturday, Nov. 29 (4:26 p.m. local Mars solar time on the 182nd Martian day, or sol, since Phoenix landed).

And now, a moment of silence…

The Phoenix lander operated for two overtime months after achieving its science goals during its original three-month mission. It landed on a Martian arctic plain on back on May 25.

As expected, reduced daily sunshine eventually left the solar-powered Phoenix craft without enough energy to keep its batteries charged.

The end of efforts to listen for Phoenix with Odyssey and NASA’s Mars Reconnaissance Orbiter had been planned for the start of solar conjunction, when the sun is almost directly between the Earth and Mars. This makes communications between Earth and Mars-orbiting spacecraft difficult, and so they are therefore minimized from now until mid-December.

Nov. 29 was selected weeks ago as the final date for relay monitoring of Phoenix because it provided several weeks to confirm the lander was really most sincerely dead, and it coincided with the beginning of solar conjunction. When they come out of the conjunction period, weather on far-northern Mars will be far colder, and the declining sunshine will have ruled out any chance of hearing from Phoenix.

Source: JPL

December 1, 2008December 24, 2015 by Nancy Atkinson

Wood Plank Found on Mars?

Panoramic image with "plank"-like rock. Credit: NASA/JPL/Cornell

Over the long holiday weekend, Universe Today was flooded with emails from readers who asked us to comment on an image taken by the Opportunity rover that appears to show a plank of wood laying on the surface of Mars. The image, above, (here’s the full resolution image) was taken in May of 2004, about four and a half years ago, in the early part of the Mars Exploration Rover mission. Since the image appears to have caused a bit of excitement across the internet recently, I decided to contact Dr. Jim Bell from Cornell University, who is also the lead scientist for the Panoramic cameras on the rovers. Bell was surprised to hear from me about the image, but happy to offer some insight. “My first reaction,” he said, “is that it’s delightful that there is such public interest in images from Mars.” Bell agreed that, indeed, it does look like a wooden plank. But does that mean it is a piece of wood on Mars? Sadly, no, says Bell.

“What you’re seeing is a piece of flat, platy, layered sulfur-rich outcrop rock like we’ve seen almost everywhere the Opportunity rover has been in Meridiani Planum,” said Bell. “Sometimes, like in this case, those flat, platy rocks have been tilted or dislodged, this one probably from the forces associated with the huge impact crater that formed nearby.”

See this image of several rocks in the area that have been tilted:

More tilted rocks. Credit: NASA/JPL/Cornell

“And this one’s being viewed edge-on,” Bell said, of the rock in question. “That edge-on view, combined with the layered nature of these rocks in general gives the surface a sort of grainy texture. So, indeed, it looks like a wooden plank on Mars.”

So, could it maybe be wood? “No, sadly,” said Bell. “I say ‘sadly’ because personally I think it would be incredible and spectacular to find a wooden plank on Mars! However, in this case, it’s just a trick of the lighting and the viewing angle.”

This image, as other Mars images that have created hubbub and speculation, is another example of our human tendency to see familiar shapes in random patterns. (Phil Plait talks about this pareidolia here.)

In fact, I spent most of the morning scanning through MER images from May 15-29, 2004 to see if I could find more images of this “wooden plank.” There’s plenty, as all of the MER images from all five cameras for both rovers are freely available on the rover website. I believe I found an image of the same rock, taken from the “backside” or opposite view: (see below)

Opportunity rover image from Sol 111. Credit: NASA/JPL

Here, it appears to be a rock, a tilted rock, but it doesn’t stand out because from this view, the lighting doesn’t make the rock appear as dark as the original view. Again, I’m not sure this is the same rock, but there are several images of tilted rocks in this region, and if this isn’t the same one, it’s one very much like it.

Here’s another image of rocks that have a similar “grainy” look to them:

Rocks with grainy surface. Credit: NASA/JPL/Cornell

For those of you who remain convinced that NASA is covering up some sort of “major” finding here, just remember a few things:

1. This image was released back in May of 2004, just a couple of days after it was taken by Opportunity. MER Principal Investigator Steve Squyres made the decision before the mission started to release all the images taken by the rovers and make them freely available to anyone. If NASA was hiding something, they wouldn’t have posted this image, as well as all the other images of the area that are available. Please, go look at them all if you have any doubt.

2. The best planetary geologists on Earth have looked at this image, and have all concluded this is just a rock. It’s an interesting rock, but a rock nonetheless. Think again if you believe some internet sleuths out there have a better understanding of this object than highly trained and experienced planetary scientists.

3. If this object really was a piece of wood, NASA and all the scientists on the MER mission would probably be shouting from the rooftops. As Jim Bell said, it would be incredible and spectacular, and don’t think for a minute these scientists wouldn’t be jumping for joy if they found something as amazing as log on Mars.

And in case you’re wondering about the other interesting feature in the image, the shiny object in the background is Opportunity’s heat shield.

November 25, 2008December 24, 2015 by Nancy Atkinson

Crazy Mars Craters

Small Crater on the North Polar Deposits Credit: NASA/JPL/University of Arizona

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With all the different spacecraft orbiting and roving on the Red Planet, we’re finding that Mars is a wonderfully diverse and dynamic planet, with some unusual landforms. Take craters, for instance, and especially a few images of craters from the Mars Reconnaissance Orbiter’s HiRISE camera. The image above shows a small impact crater on the bright north polar ice cap, near where the Phoenix lander sits, now silently. The perennial, or permanent, portion of the north polar cap consists almost entirely of water ice, and so this curious-looking crater in the ice has never melted away. And its obvious how differently craters are formed in ice; ice ejecta just doesn’t look the same as soil! This crater is about 66 meters (215 feet) in diameter, and scientists think the slightly elliptical shape of the crater is a result of an oblique, or a sideways impact (instead of straight down.) And if you think this crater is unusual, how about a crater that looks upside down….

Unusual Mound in North Polar Layered Deposits Credit: NASA/JPL/University of Arizona

Yes, this mound may actually be a buried impact crater. “The mound may be the remnant of a buried impact crater, which is now being exhumed,” said HiRISE team member Shane Byrne, of the University of Arizona. Byrne said the crater formed as the north polar ice layers were being deposited. The crater itself would have been filled in by ice after it formed.

Most of these craters are buried under the Martian surface and inaccessible to scientists and their instruments. But this crater and its mound were exhumed as erosion formed a trough above and around it. “For reasons that are poorly understood right now, the ice beneath the site of the crater is more resistant to this erosion, so that as the trough is formed, ice beneath the old impact site remained, forming this isolated hill,” Byrne said.

At high resolution, the HiRISE image shows that the mound is made up of polygonal blocks as big as 33 feet (10 meters) across.

Gullies and Light-Toned Outcrops in Crater Wall Credit: NASA/JPL/University of Arizona

Hopefully this crater rim won’t take on monumental connotations and become known as the H on Mars, but, yes, that’s what it looks like. It’s actually just dark colored outcrops in an otherwise light colored area. You can also see gullies in the crater wall just to the left of the “H,” which scientists probably find more interesting and intriguing than the H.

Lineated Valley Fill and Lobate Debris Aprons in Deuteronilus Mensae Credit: NASA/JPL/University of Arizona

And finally, since I have craters on the brain, I’ll call this image the Grey Matter Crater. Doesn’t the texture of this region look like a brain?! Actually, these landforms in the Dueteronilus Mensae region on Mars are made up of complex alignments of small ridges and pits often called “lineated valley fill.” The cause of the texture is not well understood, but may result from patterns in ice-rich soils or ice loss due to sublimation (ice changing into water vapor).

For more HiRISE (High Resolution Imaging Science Experiment) mages, browse through the ever-interesting and ever changing HiRISE website.

Source: HiRISE, Fox

November 23, 2008December 24, 2015 by Nicholos Wethington

Mars Express Maps Aurorae

If you’ve been lucky enough to ever see the aurorae (or Northern Lights) on Earth, I’m sure you’ll remember it as a spectacular sight. Fortunately, this phenomenon is not unique to the Earth: Venus, Jupiter, Saturn and Mars all have their own unique auroae, and none of them would appear to a Martian or Venusian like those of our own planet.The SPICAM instrument aboard Mars Express first observed an auroral emission event in 2004, and has since been training its UV eyes on the planet, observing a total of nine events since.

Aurorae are created by the interaction of electrically charged particles with the atmosphere of a planet. The solar wind is made up of these charged particles, and when they pass near an orbiting planet, the magnetic field channels them along its field lines (in the case of the Earth, this occurs near the poles). When the interaction occurs, light is emitted, whether it be in the infrared, visible or ultraviolet. On Earth – which has a magnetic field created by a dynamo inside of the planet – the light is visible. Saturn’s recently discovered aurorae can emit light in the infrared, and Jupiter’s aurorae are much more complicated, emitting light in the UV.

Mars doesn’t have it’s own magnetic field, though. Large stores of magnetic rocks in the crust of Mars are scattered throughout the entire planet, and the aurorae correlate with the concentrations of these rock.

A map of Mars' many magnetic fields - they're all over the place! Image Credit: NASA

SPICAM has observed nine aurorae, all near highly magnetic locations mapped by the Mars Global Surveyor Electron Reflectometer. Though there is a strong correlation between the aurorae and magnetic locations, this isn’t absolute proof that the magnetic fields in these regions are the only cause of the aurorae, but it is rather likely.

The large magnetic field structure of the Earth accelerates the charged particles, which slam into the atmosphere and spark auroral events. The dispersed nature of the magnetic fields on Mars wouldn’t do this, which leaves scientists unsure as to how exactly the aurorae are created.
“It may be that magnetic fields on Mars connect with the solar wind, providing a road for the electrons to travel along,” said Francois Leblanc, from the Service d’Aéronomie, lead author of a paper on the aurorae observed so far, titled “Observations of aurorae by SPICAM ultraviolet spectrograph on board Mars Express: Simultaneous ASPERA-3 and MARSIS measurements” which appeared in the August 2008 Journal of Geophysical research.

The elements that create the colors we see here on Earth – molecular and atomic oxygen and molecular nitrogen – are not very abundant in the thin atmosphere of Mars. SPICAM can only see in the ultraviolet, so is not equipped to detect whether the aurorae would be visible to the human eye. So will future Martian colonists looking out of their glass-domed cities have spectacular light shows every time the Sun acts up?

“We’re not sure whether the aurorae will be bright enough to be observed at visible wavelengths,” said Leblanc.

Source: ESA

November 22, 2008December 24, 2015 by Ian O'Neill

“Wasteful” Sample Storage Box Removed from Mars Science Laboratory

The MSL - a monster amongst rovers (hopefully) (NASA)

Stern: “The Mars program is slowly committing suicide in front of our very eyes”
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NASA’s Mars Science Laboratory (MSL) has been beset by technical challenges and inevitable budget overruns. The nuclear-powered rover is set for an October 2009 launch and engineers are doubling their efforts to ensure the MSL makes it to the launchpad on time. In an attempt to save money and (hopefully) time, MSL program managers have decided to remove a $2 million component from the car-sized wheeled robot. A sample storage box was conceived long after the initial MSL science goals were drawn up (a pretty controversial decision in itself), so analysed rock samples could be saved for a possible future Mars sample-return mission.

Now NASA has deemed the box “of low science value” and “wasteful” on resources that could be directed elsewhere, but outspoken critics have pointed out that by removing the box is just another component on the road to the demise of NASA’s Mars exploration program…

Wouldn’t it be great if we could dig up samples of Martian rock and launch it back to Earth? Just think about the in-depth science that could be carried out on a sample removed directly from the Mars surface. Although rovers and landers are great for in-situ experiments, you still cannot beat analysis by a scientist. Assuming infinite resources, a Mars sample return mission would be technologically possible, but in the current climate of budget cuts and overspending, it is virtually impossible. The money, quite simply, is better spent elsewhere.

So, there’s NASA constructing the most advanced rover to be sent to Mars, ever. It will be a long-term mission, powered not by sunlight but by long-lasting radioisotope thermal generators (RTGs). It will do amazing science whilst dominating the Martian landscape by day and by night. After the MSL design was drawn up, a new piece of equipment was dreamt up: a sample storage box. This may not sound very exciting, after all, its only purpose is to store rocks. Why? So a future mission can retrieve the samples and return them to Earth.

Last week, it was decided that the storage box was surplus to requirements and it will be removed from the MSL. Although it had already been built, MSL project scientist John Grotzinger (Caltech) pointed out that the instrument would have taken time away from the other instruments.

“The cache would have tied our hands to some extent,” Grotzinger said. “Now it restores our freedom.”

The MSL has run up a pricetag of over $1.5 billion, and it is expected to balloon to $2 billion by the time it launches to the Red Planet, so any excess cost should be trimmed where necessary. Alas, the storage box is low on the list of priorities and was dropped, even though $2 million had already been wasted in its development. NASA’s rationale is that more time and money will need to be put into the cache, so they may as well cut their losses.

This move isn’t a popular decision however. Ex-NASA space sciences chief Alan Stern (who resigned in March after the controversy surrounding the erroneous announcement that funds to the existing Mars rovers would be cut), is very critical of the move. “The Mars program is slowly committing suicide in front of our very eyes,” said Stern. “The only concrete step toward a sample return has been tossed after it has already been built. How does that save money?”

Indeed, this may be a signal that a sample return mission is not on the cards, certainly not involving the MSL. I would question why the sample storage box was included in the MSL at all, surely any future sample return attempt would be carried out by a devoted sample return mission? What was the motivation behind picking up rocks the MSL had analysed, only to store them for many years until a theoretical sample return robot collects the box?

When the cache was originally announced, scientists pointed out that the samples will have probably degraded by the time they are sent back anyway, so what’s the point?

Either way, the box now frees up some space on the MSL for an instrumentation cleaning station, but I can’t help but think the $2 million waste could have been prevented…

Original source: Herald Tribune

November 21, 2008December 24, 2015 by Ian O'Neill

Mars Atmospheric “Bubbles” Carried Away by the Solar Wind

Why do planets like Mars have a different atmosphere than Earth? Credit: NASA

[/caption]Mars is a strange planet.

There is evidence that the Red Planet once played host to a thick atmosphere and vast oceans. However, at some point in its evolution, the planet seemed to leak the majority of its atmospheric gases into space, and its oceans evaporated (or froze and then sublimated, depending on how fast atmospheric pressure was lost). There are several theories as to how the Martian atmosphere wasted away to 1% of that of the Earth’s, including the slow erosion by solar wind particles and a sudden, catastrophic asteroid impact, blasting the atmosphere into space.

Planetary scientists have known for a long time that the Martian magnetic field is very weak and therefore has little protective strength from the continuous solar wind. Through analysis of data from the retired NASA Mars Global Surveyor (MGS) satellite, a new insight has been gained.

Far from being benign however, this weak crustal magnetic field may actually be having an adverse effect on the atmosphere, capturing atmospheric particles in magnetic “bubbles” (a.k.a. plasmoids) over a thousand kilometres wide, before being blown en-mass into space…

The erosion of the Martian atmosphere by the solar wind has been long suspected as the primary mechanism behind the loss of Martian air. Although Mars air is significantly different to our own (the Martian atmosphere is primarily CO₂-based, whereas the terrestrial atmosphere has a breathable nitrogen-oxygen mix), it was once thought to be much more dense than it is today.

So where did the atmosphere go? As the Martian magnetosphere is pretty insignificant (scientist believe that the global magnetic field may have been a lot stronger in the past and possibly damaged by an asteroid impact), there is little to deflect energetic solar wind ions from interacting with the atmosphere below. On Earth, we have a very strong magnetosphere acting as an invisible forcefield, preventing charged particles from entering our atmosphere. Mars does not have this luxury.

During the Mars Global Surveyor mission, launched in 1996 (ending in 2006), the satellite detected a very patchy magnetic field originating from the Martian crust, predominately in the southern hemisphere. The natural thought would be that, although weak, this patchy field might provide some limited protection for the atmosphere. According to new research using old MGS data, this is probably not the case; the crustal magnetic field may be contributing to, possibly accelerating, the air loss.

Dave Brain of UC Berkeley presented this slide at the 2008 Huntsville Plasma Workshop to explain in cartoon fashion how plasmoids carry air away from Mars.

As the patchy crustal magnetic field wells up from the Martian surface, it creates “umbrellas” of magnetic flux, trapping charged atmospheric particles. Dozens of magnetic umbrellas cover up to 40% of Mars (primarily concentrated in the south), reaching above the atmosphere. These magnetic structures are therefore open to attack from the solar wind.

“The umbrellas are where coherent chunks of air are torn away,” said David Brain of UC Berkeley, who presented his MGS research at the 2008 Huntsville Plasma Workshop on October 27th.

Although this might sound dramatic, there is a real possibility that this process has been observed on Mars for the first time. The magnetic umbrellas reach through the atmosphere and feel dynamic pressure from the solar wind. What happens next is a well known mechanism in the field of magnetohydrodynamics (MHD): reconnection.

As the crustal umbrellas make contact with the interplanetary magnetic field (IMF) carried by the solar wind, there is a chance reconnection may occur. According to David Brain, the MGS passed through such a reconnection region during one of its orbits. “The joined fields wrapped themselves around a packet of gas at the top of the Martian atmosphere, forming a magnetic capsule a thousand kilometers wide with ionized air trapped inside,” he said. “Solar wind pressure caused the capsule to ‘pinch off’ and it blew away, taking its cargo of air with it.”

Since this first result, Brain has found a further dozen magnetic “bubbles” carrying chunks of the Martian ionosphere with them. These bubbles are known as “plasmoids” as they contain charged particles, or plasma.

Brain is keen to point out that these results are far from conclusive. For example, the MGS was only equipped to detect one charged particle, the electron; ions have different characteristics and may therefore be affected differently. Also, the satellite took measurements at a constant altitude at the same local time of day. More data during different times and different altitudes are required.

One such NASA mission that might be able to assist in the plasmoid hunt is the Mars Atmosphere and Volatile Evolution satellite (MAVEN), scheduled for launch in 2013. MAVEN will analyse the Martian atmosphere to specifically study erosion by the solar wind, detecting electrons and ions; measuring not only the magnetic, but the electric field too. MAVEN’s elliptical orbit will also allow the probe to investigate various altitudes at different times.

So we await MAVEN to prove or disprove Brain’s plasmoid theory. Either way, this is some tantalizing evidence pointing to a rather unexpected mechanism that could be, quite literally, ripping Mars’ atmosphere into space…

Source: NASA