The private spaceflight company SpaceX has done it again, and this latest achievement is an important one.
Crew Dragon berthed with the space station at 2:51 a.m. PT [NASA]
We space writers are very familiar with Elon Musk’s human spaceflight dreams that can be encapsulated in his well-known goal to “make humanity multi-planetary,” starting with a Mars settlement. And today, that goal took another step closer to reality.
I’ve been following Musk’s rocket adventures ever since his early days of exploding single-engine rockets in the South Pacific. Back then, Musk was a “dreamer” and more than a little eccentric. His eccentricities are well documented, but the world’s best known billionaire-entrepreneur is a dreamer no more. The first successful flight of a Falcon 1 happened on Sept. 28, 2008. (You can read my 2008 Space Lifestyle Magazine article on that topic, page 36) A little over a decade later, the Falcon 1 has rapidly evolved into the reusable Falcon 9 workhorse and the Falcon Heavy and, with key partnerships with NASA and companies that need to get stuff into orbit cheaply, SpaceX has developed the human-rated Dragon spacecraft to ultimately get astronauts to the space station, and beyond.
After proving itself in the cargo-delivery arena, the Dragon has now won its human-spaceflight wings: an (uncrewed) Crew Dragon is now attached to the International Space Station’s Harmony module and the outpost’s astronauts have entered the vehicle.
Building a commercially-viable space infrastructure is paramount if humanity is to truly become multi-planetary, and through partnerships between private business and government contracts, today’s achievement is proof that this model can work.
Too often, governments lack the long-term vision for human space exploration, instead plowing money into bloated, politically motivated, and ultimately doomed federally-funded projects. SpaceX may be an exhausting company to work for, but its ultimate mission is crystal clear. It’s not a satellite-launching company, it’s just doing that to build funds to do the Next Big Thing. Dragon’s autonomous berthing with the space station is That Big Thing that will drive more investment into getting stuff beyond Earth orbit.
Musk’s interim target — before getting humans to Mars — is the moon, to create a permanently-crewed lunar base. How that will shape up remains to be seen, but if there’s one thing I’ve learnt from following his dreams of getting into space on a reusable spaceflight infrastructure, it’s don’t bet against SpaceX and Elon Musk’s “eccentricities.”
The impact crater Stickney (and the smaller crater Limtoc) as imaged by NASA’s Mars Reconnaissance Orbiter in 2008 [NASA/JPL-Caltech]
Earth has them. So does the Moon. As does Mars. And now we know dwarf planet Ceres has them, too. Could a Martian moon also have them? Well, according to new research, they could explain the mystery behind Phobos’ strange lines that are carved into its dusty surface.
What am I talking about? Boulders. Specifically boulders that have been on the move. Boulders that — in the presence of a gravitational field, no matter how weak — roll and bounce, leaving their grooves on some of our most beloved celestial bodies.
“These grooves are a distinctive feature of Phobos, and how they formed has been debated by planetary scientists for 40 years,” said planetary scientist Ken Ramsley (Brown University) who led the work, in a statement. “We think this study is another step toward zeroing in on an explanation.”
Ever since NASA’s Mariner and Viking missions spied Phobos’ lines in the 1970’s, scientists have debated what could have created them. The ancient natural satellite of Mars is only 27 kilometers wide and possesses long, etched lines that, in some cases, loop around the entirety of the moon’s circumference.
A popular hypothesis for these lines focused on the possibility that Phobos is a dying moon; the tidal forces from Mars ultimately pulling the body apart. In this scenario, the lines are a sign that the moon’s interior is crumbling, creating fault lines in the surface that our space robots have been able to image. Another idea is that the lines were created by crater chains; multiple impacts by smaller rocks that etched out long lines around Phobos’ surface.
However, according Ramsley’s study, which is published in the journal Planetary and Space Science, the real mechanism that created Phobos’ stripes is far more elegant, and more familiar to us Earthlings. What’s more, it was one of the original hypotheses that was posited when the lines were discovered over 40 years ago.
In 1998, NASA’s Mars Global Surveyor imaged Phobos’ stripes [NASA/JPL-Caltech/LLNL]
You see, Phobos has a huge, nine-kilometer-wide crater on one side, called Stickney (named after Angeline Stickney who motivated the search for Mars’ natural satellites in the late 19th Century), that was excavated by a massive impact in the moon’s ancient past. Using computer models, the researchers simulated what would happen post-impact and where the excavated material (including some hefty boulders) would have ended up. Although a huge quantity of material would have been lost to space during the Stickney impact, a few large rocks may have been kicked across the moon’s surface — these boulders would have rolled slowly, slow enough to be held in contact with Phobos, but fast enough, in some cases, to make more than one trip around the moon.
But many of these lines intersect one another and don’t appear to be radially blasted from the crater. Also, there are regions on the surface where the lines entirely disappear. Ramsley’s simulation explains these oddities.
The simulations show that because of Phobos’ small size and relatively weak gravity, Stickney stones just keep on rolling, rather than stopping after a kilometer or so like they might on a larger body. In fact, some boulders would have rolled and bounded their way all the way around the tiny moon. That circumnavigation could explain why some grooves aren’t radially aligned to the crater. Boulders that start out rolling across the eastern hemisphere of Phobos produce grooves that appear to be misaligned from the crater when they reach the western hemisphere.
This also helps to explain why many of these lines cross and superimpose themselves on one another: Grooves that were laid down by boulders rolling immediately after the impact were crossed by boulders that completed a complete traverse of the globe of the moon, some ending up where they started, minutes or hours later. This also explains why Stickney itself has grooves inside its crater basin.
The dark surface of Phobos with Mars as the backdrop, as seen by the European Mars Express [ESA]
But there’s a blank area on Phobos that appears to contain no grooves, a phenomenon that the simulation also addresses. This region is located at a comparatively low elevation part of Phobos, surrounded by a higher-elevation lip. “It’s like a ski jump,” said Ramsley. “The boulders keep going but suddenly there’s no ground under them. They end up doing this suborbital flight over this zone.
“We think this makes a pretty strong case that it was this rolling boulder model accounts for most if not all the grooves on Phobos.”
As a fan of rolling boulders on other worlds, I particularly enjoy imagining the lumbering slow roll of these massive rocks that circumnavigated Phobos. They had to keep their roll slow so not to achieve escape velocity, but fast enough to leave their indelible marks for humans to ponder their origins.
A view from the Viking 1 deck, showing trenches its robotic arm dug out to acquire samples for testing [NASA/JPL-Caltech/Roel van der Hoorn]
When rains came to one of the driest places on Earth, an unprecedented mass extinction ensued.
The assumption was that this rainfall would turn this remote region of the Atacama Desert in Chile into a wondrous, floral haven — dormant seeds hidden in the parched landscape would suddenly awake, triggered by the “life-giving” substance they hadn’t seen for centuries — but it instead decimated over three quarters of the native bacterial life, microbes that shun water in favor of the nitrogen-rich compounds the region has locked in its dry soil.
In other words, death fell from the skies.
“We were hoping for majestic blooms and deserts springing to life. Instead, we learned the contrary, as we found that rain in the hyperarid core of the Atacama Desert caused a massive extinction of most of the indigenous microbial species there,” said astrobiologist Alberto Fairen, who works at Cornell Cornell University and the Centro de Astrobiología, Madrid. Fairien is co-author of a new study published in Nature’s Scientific Reports.
“The hyperdry soils before the rains were inhabited by up to 16 different, ancient microbe species. After it rained, there were only two to four microbe species found in the lagoons,” he added in a statement. “The extinction event was massive.”
El Valle de la Luna (Valley of the Moon) near San Pedro de Atacama looks very Mars-like [photo taken during #MeetESO in 2016, Ian O’Neill]
Climate models suggest that these rains shouldn’t hit the core regions of Atacama more than once every century, though there is little evidence of rainfall for at least 500 years. Because of the changing climate over the Pacific Ocean, however, modern weather patterns have shifted, causing the weird rain events of March 25 and Aug. 9, 2015. It also rained more recently, on June 7, 2017. Besides being yet another reminder about how climate change impacts some of the most delicate ecosystems on our planet, this new research could have some surprise implications for our search for life on Mars.
Over forty years ago, NASA carried out a profound experiment on the Martian surface: the Viking 1 and 2 landers had instruments on board that would explicitly search for life. After scooping Mars regolith samples into their chemical labs and adding a nutrient-rich water mix, one test detected a sudden release of carbon dioxide laced with carbon-14, a radioisotope that was added to the mix. This result alone pointed to signs that Martian microbes in the regolith could be metabolizing the mixture, belching out the CO2.
Alas, the result couldn’t be replicated and other tests threw negative results for biological activity. Scientists have suggested that this false positive was caused by inorganic reactions, especially as, in 2008, NASA’s Phoenix Mars lander discovered toxic and highly reactive perchlorates is likely common all over Mars. Since Viking, no other mission has attempted a direct search for life on Mars and the missions since have focused on seeking out water and past habitable environments rather than directly testing for Mars germs living on modern Mars.
With this in mind, the new Atacama microbe study could shed some light on the Viking tests. Though the out-gassing result was likely a false positive, even if all the samples collected by the two landers contained microscopic Martians, the addition of the liquid mix may well have sterilized the samples — the sudden addition of a large quantity of water is no friend to microbial life that has adapted to such an arid environment.
“Our results show for the first time that providing suddenly large amounts of water to microorganisms — exquisitely adapted to extract meager and elusive moisture from the most hyperdry environments — will kill them from osmotic shock,” said Fairen.
Another interesting twist to this research is that NASA’s Mars rover Curiosity discovered nitrate-rich deposits in the ancient lakebed in Gale Crater. These deposits might provide sustenance to Mars bacteria (and may be a byproduct of their metabolic activity), like their interplanetary alien cousins in Atacama.
As water-loving organisms, humans have traditionally assumed life elsewhere will bare similar traits to life as we know it. But as this study shows, some life on Earth can appear quite alien; the mass extinction event in the high deserts of Chile could teach us about how to (and how not to) seek out microbes on other planets.
The Earth and Mars are currently on exact opposite sides of the sun — a celestial situation known as “Mars solar conjunction” — a time when we have no way of directly communicating with satellites and rovers at the Red Planet. So, when the Solar and Heliospheric Observatory (SoHO) spotted a huge (and I mean HUGE) bubble of superheated plasma expand from the solar disk earlier today (July 23), it either meant our nearest star had launched a vast coronal mass ejection directly at Earth or it had sent a CME in the exact opposite direction.
As another solar observatory — the STEREO-A spacecraft — currently has a partial view of the other side of the sun (it orbits ahead of Earth’s orbit, so it can see regions of the sun that are out of view from our perspective), we know that this CME didn’t emanate from the sun’s near side, it was actually launched away from us and Mars will be in for some choppy space weather very soon.
It appears the CME emanated from active region (AR) 2665, a region of intense magnetic activity exhibiting a large sunspot.
“If this explosion had occurred 2 weeks ago when the huge sunspot was facing Earth, we would be predicting strong geomagnetic storms in the days ahead,” writes Tony Phillips of Spaceweather.com.
CMEs are magnetic bubbles of solar plasma that are ejected at high speed into interplanetary space following a magnetic eruption in the lower corona (the sun’s lower atmosphere). From STEREO-A’s unique vantage point, it appears the CME detected by SoHO was triggered by a powerful solar flare that generated a flash of extreme-ultraviolet radiation (possibly even generating X-rays):
Observation by STEREO-A of the flaring event that likely triggered today’s CME (NASA/STEREO)
When CMEs encounter Earth’s global magnetic field, the radiation environment surrounding our planet increases, posing a hazard for satellites and unprotected astronauts. In addition, if the conditions are right, geomagnetic storms may commence, creating bright aurorae at high latitudes. These storms can overload power grids on the ground, triggering mass blackouts. Predicting when these storms will occur is of paramount importance, so spacecraft such as SoHO, STEREO and others are constantly monitoring our star’s magnetic activity deep inside the corona and throughout the heliosphere.
Mars, however, is a very different beast to Earth in that it doesn’t have a strong global magnetosphere to shield against incoming energetic particles from the sun, which the incoming CME will be delivering very soon. As it lacks a magnetic field, this CME will continue to erode the planet’s thin atmosphere, stripping some of the gases into space. Eons of space weather erosion has removed most of the Martian atmosphere, whereas Earth’s magnetism keeps our atmospheric gases nicely contained.
When NASA and other space agencies check in with their Mars robots after Mars solar conjunction, it will be interesting to see if any recorded the space weather impacts of this particular CME.
While Opportunity and Curiosity continue to explore the surface of Mars, the launch date of NASA’s next big rover mission is on the horizon. And here’s a stunning artist’s impression of the mission that NASA released on Tuesday.
Wait. Isn’t that Curiosity?
No. While the Mars 2020 rover will certainly look like Curiosity, as many of the current rover’s design features will be worked into NASA’s next six-wheeled robot, there will be some key differences in the next rover’s science.
Rather than seeking out past and present habitable environments (as Curiosity is currently doing on the slopes of Mount Sharp), one of Mars 2020’s stated science goals is to directly search for biological signatures of past and present microbial life on Mars. This next-generation rover will also feature a drill that can bore deep into rocks, pull samples and store them on the Martian surface for a possible future sample return mission.
Mars’ moons were likely formed by a ring of debris blasted into space after the Red Planet was hit by a massive impact and, when the moon Phobos disintegrates in 70 million years, another ring may form.
Sunrise over Gale Crater as seen by NASA’s Mars rover Curiosity and how it might look if the Red Planet had a ring system (NASA/JPL-Caltech-MSSS, edit by Ian O’Neill)
Mars is currently known as the “Red Planet” of the solar system; its unmistakable ruddy hue is created by dust rich in iron oxide covering its landscape. But in Mars’ ancient past, it might have also been called the “Ringed Planet” of the inner solar system and, in the distant future, it may sport rings once more.
The thing is, we live in a highly dynamic solar system, where the planets may appear static over human (or even civilization) timescales, but over millions to billions of years, massive changes to planetary bodies occur frequently. And should there be a massive impact on a small rocky world — on Mars, say — these changes can be nothing short of monumental.
In new NASA-funded research published in the journal Nature Geoscience, planetary scientists have developed a new model of Mars when it was hit by a massive impact over 4 billion years ago. This catastrophic impact created a vast basin called the Borealis Basin in the planet’s northern hemisphere and the event could be part of the reason why Mars lacks a global magnetic field — it’s hypothesized that a powerful impact (or series of impacts) caused massive disruption to the Martian inner dynamo.
But the impact also blasted a huge amount of rocky debris from Mars’ crust into space, ultimately settling into a ring system, like a miniaturized rocky version of Saturn. Over time, as the debris drifted away from Mars and settled, rocky chunks would have formed under gravity and these “moonlets” would have clumped together to form larger and larger moons. So far, so good; this is how we’d expect moons to form. But there’s a catch.
Phobos as imaged by Europe’s Mars Express mission (ESA)
After forming in Mars orbit, any moon would have slowly lost orbital altitude, creeping toward the planet’s so-called Roche Limit — a region surrounding any planetary body that is a bad place for any moon to hang out. The Roche Limit is the point at which a planet’s tidal forces become too great for the structural integrity of an orbiting body. When approaching this limit, the closest edge of the moon to the planet will experience a greater tidal pull than the far side, overcoming the body’s gravity. At some point, something has to give and the moon will start to break apart.
And this is what’s going to happen to Phobos in about 70 million years. Its orbit is currently degrading and when it reaches this invisible boundary, tidal stresses will pull it apart, trailing pieces of moon around the planet, some debris falling onto the Martian surface as a series of meteorite impacts, while others remain in orbit.
The research, carried out by David Minton and Andrew Hesselbrock of Purdue University, Lafayette in Indiana, theorizes that mysterious deposits of material around Mars’ equator might have come from the breakup of ancient moons that came before Phobos and Deimos.
“You could have had kilometer-thick piles of moon sediment raining down on Mars in the early parts of the planet’s history, and there are enigmatic sedimentary deposits on Mars with no explanation as to how they got there,” said Minton. “And now it’s possible to study that material.”
According to their model, each time a moon broke apart to create a ring, the next moon would be five times smaller than its predecessor.
In short, Mars and its moon may appear to be pretty much unchanged for billions of years, but the researchers think that up to seven moon-ring cycles have occurred over the last 4.3 billion years and Mars is on the verge (on geological timescales) of acquiring rings once more. Fascinating.
Panorama mosaic taken by Curiosity’s Mastcam on Sol 413 of its mission inside Gale Crater. Credit: NASA/JPL-Caltech/MSSS, edit by Ian O’Neill
As NASA has been shuttered by the insane U.S. government shutdown, there’s been little in the way of news releases from NASA (site offline) or NASA’s Jet Propulsion Laboratory (site still online, but no recent updates posted). In this Mars Science Laboratory science lull, I’ve found myself obsessively trawling the mission’s raw image archive so I can get my fix of high-resolution imagery from Curiosity’s ongoing mission inside Gale Crater.
While getting lost in the Martian landscape once more, I started tinkering with Curiosity’s raw photos; zooming in, adjusting the contrast, brightness and color. One thing led to another and I found myself stitching together various photos from the rover’s Mastcam camera. Being awash with photographs with little professional insight from mission scientists (as, you know, a noisy minority at Capitol Hill has gagged them by starving the agency of funds), I started to tinker in Photoshop, blindly trying to stitch a selection of Mastcam photos together to see an updated Martian panorama once more. This is the result.
Of particular interest, I found myself staring at the precariously-shaped boulder to the far right of the panorama. I can only guess what geological processes shaped it that way — Wind action? Ancient water flow? — or whether it had simply landed that way after getting blasted from an impact crater, but I was curious as to what JPL mission scientists are making of it. Alas, we’ll have to wait a little longer for the awesome Mars science to begin flowing again.
Here’s that rock:
It felt nice to be absorbed in the Mars landscape again. The photo stitching is rough in places (by far the hardest task was getting the brightness and contrast correct in each photo) and I lack any calibration tools to ensure the color is correct or that the orientation is sound, but it satisfied my curiosity as to what Curiosity was up to on the Red Planet. It has, after all, been over a year since the historic landing of the NASA mission and the regular news updates from NASA and JPL have become something of an intellectual opiate.
Going cold turkey, apparently, makes a space blogger itchy.
Trails of Mars rocks that have rolled down the slope of a crater rim as imaged by the HiRISE camera. Credit: NASA/JPL/Univ. of Arizona.
It’s always fascinating to see evidence of active geological processes on Mars. And with the help of the armada of robots in orbit and roving the Red Planet, there are plenty of opportunities to see the planet in action.
Take this recent image from the High-Resolution Imaging Science Experiment (HiRISE) camera aboard NASA’s Mars Reconnaissance Orbiter (MRO) for example. In this striking scene — which is a little over one kilometer wide — the bright trails of rocks that have rolled down a sloping crater rim after being dislodged from the top are visible from space. The rocks have obviously bounced on their way, leaving dotted impressions as they rolled. Some have reared in wide arcs, following the topography of the landscape. Others have hit other rocks on their way down, dislodging them, creating secondary cascades of smaller boulders.
“The many boulder tracks in this image all seem to emanate from a small alcove near the rim of the crater,” describes HiRISE Targeting Specialist Nicole Baugh. “They spread out downslope and finally terminate near the crater floor. A high-contrast stretch of the area where the tracks stop shows lots of boulders, some still at the ends of the tracks.”
A rough estimate from the high-resolution imagery suggests some of these Mars boulders are over a meter wide. Future Mars astronauts beware: don’t camp out at the bottom of Martian hills! There’s no vegetation to hold big rocks in place or slow their speed. As previous observations of Mars “avalanches” suggest, weathering through the expansion of water ice (frost action) and/or rapid vaporization of carbon dioxide ice likely trigger pretty extreme downfalls of debris. It would be a bummer to travel all the way to Mars, survive the ravages of solar radiation, a daring descent and landing only to get flattened by a wayward chunk of rock when you set up camp.
I’ve always had a special joy for surveying HiRISE observations; it’s a very privileged window to this alien landscape that, in actuality, has many similar geological processes we find on Earth. And so here we have a collection of boulders that, somehow, became dislodged and stormed down from the rim of a crater. If we saw such an event in person, we might note the unnatural bounce these boulders have in the roughly one-third Earth gravity. But we’d also have to find shelter fast, as just like rolling boulders on Earth, those things will flatten you.
A view from Curiosity’s front hazcam of the sandy Mars soil the rover scooped samples of for analysis by its SAM instrument (NASA/JPL-Caltech)
UPDATE 2:So it turns out that Curiosity does have data to suggest that organics and perchlorates may be present in the Mars soil. As NASA keeps reminding us, this is not “proof” of organics, it’s “promising data.” Regardless, the media has made up their own mind as to what it means. As for Voyager 1, my speculation that it has left the solar system wasn’t quite correct… close, but she hasn’t left the heliosphere, yet.
UPDATE 1:That whole thing I said in my Al Jazeera English op-ed about being blinkered on the organics explanation for the “big” news on Monday? Well, case in point, as tweeted by @MarsToday on Sunday night, perhaps Curiosity has discovered further evidence for perchlorates on Mars. I have no clue where this information is sourced, and I’m not going to speculate any more, but if perchlorates have been discovered in Gale Crater, it would support the findings of NASA’s 2008 Mars Phoenix lander findings of perchlorate and possible liquid water brine in the arctic regions of the Red Planet. Place your bets…
Over the last bizarre few days, a key NASA scientist (almost) spilled the beans on a “historic” discovery by the Mars Science Laboratory (MSL) rover Curiosity. Then, speculation ran wild. Had NASA’s newest Mars surface mission discovered organics? Feeling the need to stamp out the glowing embers of organic excitement ahead of the Dec. 3 AGU press conference, NASA said that there would be no big announcement on Monday. But then the agency went even further, issuing a terse statement to point out that the speculation is wrong. “At this point in the mission, the instruments on the rover have not detected any definitive evidence of Martian organics,” said NASA.
So now we’re left, understandably, wondering what lead MSL scientist John Grotzinger was referring to. I think it’s safe to assume that he wasn’t misquoted by the NPR journalist who happened to be sitting in his office when the MSL team was receiving data from the mission’s Sample Analysis at Mars (SAM) instrument. And if we take NASA’s damage-controlling statements at face value, Grotzinger was just getting excited for all the data being received from the rover — after all, the entire mission is historic.
As a science media guy with a background in science, I totally ‘get’ what the MSL team are going through. Scientists are only human and whether or not Grotzinger was getting excited for a specific “historic” find or just getting generally excited for all the “historic” data streaming from the rover, is irrelevant. Perhaps he should have been more careful as to the language he used when having an NPR reporter sitting in the same room as him, but that’s academic, I’m pretty sure that if I was leading the most awesome Mars mission in the history of Mars missions I’d be brimming over with excitement too. The scientific process is long and can often seem labored and secretive to the media and public — rumors or a few slipped words from scientists is often all that’s needed to spawn the hype. But for the scientific process to see its course, data needs to be analyzed, re-analyzed and theories need to be formulated. In an announcement as important as “organics on Mars,” the science needs to be watertight.
However, I can’t help but feel that, in NASA’s enthusiasm to “keep the lid” on speculation, that they are setting themselves up for a backlash on Monday.
If the AGU press conference is just “an update about first use of the rover’s full array of analytical instruments to investigate a drift of sandy soil,” as the NASA statement says, won’t there be any mention of organics? Will this be a similar announcement to the sampling of Mars air in the search for methane? The upshot of that Nov. 2 press conference was that the Mars air had been tested by SAM and no methane (within experimental limits) had been discovered… yet. But this was a sideline to the announcement of some incredible science as to the evolution of the Martian atmosphere.
This time, although there may not be “definitive,” absolute, watertight proof of organics, might mission scientists announce the detection of something that appears to be organics… “but more work is needed”? It’s a Catch 22: It’s not the “historic” news as the experiment is ongoing pending a rock-solid conclusion; yet it IS “historic” as the mere hint of a detection would bolster the organics experiments of the Viking landers in the 1970s and could hint at the discovery of another piece of the “Mars life puzzle.” And besides, everything Curiosity does is “historic.”
In NASA’s haste to damper speculation, have they cornered themselves into not making any big announcements on Monday? Or have they only added to the speculation, bolstering the media’s attention? Besides, I get the feeling that the media will see any announcement as a “big” announcement regardless of NASA scientists’ intent. Either way, it’s a shame that the hype may distract from the incredible science the MSL team are carrying out every single day.
Meanwhile, in deep space, a little probe launched 35 years ago is edging into the interstellar medium and NASA’s Voyager Program team are also holding an AGU press conference on Monday. Although there have been no NPR journalists getting the scoop from mission scientists, it’s worth keeping in mind that Voyager 1 really is about to make history. In October, I reported that the particle detectors aboard the aging spacecraft detected something weird in the outermost reaches of the Solar System. As Voyager 1 ventures deep into the heliosheith — the outermost component of the heliosphere (the Sun’s sphere of influence) — it detected inexplicable high-energy particles. The theory is that these particles are being accelerated by the magnetic mess that is the outermost reaches of the Solar System. But there is growing evidence in particle detections and magnetometer readings that the probe may have just left the Solar System, completely escaping the heliosphere.
A big hint is in the following graphs of data streaming from Voyager 1. The first plot shows the increase in high-energy cosmic ray particle counts. These high-energy particles typically originate from beyond the heliosphere. The bottom plot shows lower-energy particles that originate from the solar wind. Note how the lower-energy particle counts fell off a cliff this summer, and how the high-energy particles have seen a marked increase at around the same period:
High-energy cosmic ray count as detected by Voyager 1. Credit: NASA
Low-energy cosmic ray count as detected by Voyager 1. Credit: NASA
So, in light of the media-centric Curiosity debate over what is “historic” and what’s not “historic” enough to be announced at conferences, I’m getting increasingly excited for what the Voyager team have got to say tomorrow. It’s inevitable that Voyager 1 will leave the Solar System, but will NASA call it at the AGU? Who knows, but that would be historic, just without the hype.
This nearly global mosaic of observations made by the Mars Color Imager on NASA’s Mars Reconnaissance Orbiter on Nov. 18, 2012, shows a dust storm in Mars’ southern hemisphere. Credit: NASA
As the sols march on, NASA’s brand new nuclear-powered rover Curiosity has detected a dramatic change in its surrounding atmosphere. A once-clear vista of the distant rim of Gale Crater now looks smoggy — almost like the gray-brown-yellow stuff that hangs above Los Angeles on a hot summer’s day. So what’s causing this change in opacity?
As can be seen in the above global view of Mars, NASA’s Mars Reconnaissance Orbiter took a near-continuous observation of the planet on Nov. 18 with its Mars Color Imager. The mosaic has picked out an assortment of geographical features, but there’s one rather ominous atmospheric feature (white arrows) that grabbed the attention of Malin Space Science Systems’ Bruce Cantor.
A regional dust storm is brewing and Cantor first observed the storm on Nov. 10. He reported the detection to NASA’s Mars Exploration Rover team who manage Opportunity. Although the storm is over 800 miles from the tenacious rover, dust storms are of a concern for any solar powered surface mission, especially for a rover that has outlived its expected mission lifetime by several years. Opportunity’s solar panels are already covered in dust, so should there be an additional dip in sunlight due to a dusty atmosphere there could be an impact on its mission. Additional dust layers on the panels wouldn’t help either.
Opportunity does not have a weather station, but its cameras have detected a slight drop in atmospheric clarity. Curiosity, on the other hand, does have a weather station — called the Rover Environmental Monitoring Station (REMS) — and has been closely monitoring the atmospheric variability over the last few days, detecting a decreased air pressure and a slight rise in overnight low temperature. This is in addition to the dramatic loss in visibility. In short, it sounds like Curiosity can sense a storm in the air.
Six Navcam images pointed toward the horizon taken over the course of Curiosity’s time near Rocknest document changes in the transparency of the atmosphere. NASA/JPL/ Egorov Vitaly (“Zelenyikot”)
“This is now a regional dust storm. It has covered a fairly extensive region with its dust haze, and it is in a part of the planet where some regional storms in the past have grown into global dust hazes,” said Rich Zurek, chief Mars scientist at NASA’s Jet Propulsion Laboratory, Pasadena, Calif. “For the first time since the Viking missions of the 1970s, we are studying a regional dust storm both from orbit and with a weather station on the surface.”
Now this is the cool bit. We currently have an armada of Mars orbiters, plus two generations of Mars rovers doing groundbreaking work on opposite sides of the red planet. We are in an unprecedented age of planetary exploration where a network of robots all work in concert to aid our understanding of how the planet works. In this case, local weather changes are being observed around two surface missions while corroborating data is being gathered hundreds of miles overhead.
Starting on Nov. 16, the Mars Climate Sounder instrument on the Mars Reconnaissance Orbiter detected a warming of the atmosphere at about 16 miles (25 kilometers) above the storm. Since then, the atmosphere in the region has warmed by about 45 degrees Fahrenheit (25 degrees Celsius). This is due to the dust absorbing sunlight at that height, so it indicates the dust is being lofted well above the surface and the winds are starting to create a dust haze over a broad region.
Warmer temperatures are seen not only in the dustier atmosphere in the south, but also in a hot spot near northern polar latitudes due to changes in the atmospheric circulation. Similar changes affect the pressure measured by Curiosity even though the dust haze is still far away.
We’re monitoring weather on another planet people! If that’s not mind-blowing, I don’t know what is.
Note: Apologies for the Astroengine.com hiatus, I’ve been somewhat distracted with writing duties at Discovery News and Al Jazeera English. If you’re ever wondering where I’ve disappeared to, check in on my Twitter feed, I tweet a lot!
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