Modern astronomy and space exploration has blessed us with a plethora of wonderful images. Whether they were images of distant planets, stars and galaxies taken by Earth-based telescopes, or close-ups of planets or moons in our own Solar System by spacecraft, there has been no shortage of inspiring pictures. But what would it look like to behold planet Earth from another celestial body?
We all remember the breathtaking photos taken by the Apollo astronauts that showed what Earth looked like from the Moon. But what about our next exploration destination, Mars? With all the robotic missions on or in orbit around the Red Planet, you’d think that there would have been a few occasions where they got a good look back at Earth. Well, as it turn out, they did!
Pictures from Space:
Pictures of Earth have been taken by both orbital missions and surface missions to Mars. The earliest orbiters, which were part of the Soviet Mars and NASA Mariner programs, began arriving in orbit around Mars by 1971. NASA’s Mariner 9 probe was the first to establish orbit around the planet’s (on Nov. 14, 1971), and was also the first spacecraft to orbit another planet.
The first orbiter to capture a picture of Earth from Mars, however, was the Mars Global Surveyor, which launched in Nov. 7th, 1996, and arrived in orbit around the planet on Sept. 12th, 1997. In the picture (shown above), which was taken in 2003, we see Earth and the Moon appearing closely together.
At the time the picture was taken, the distance between Mars and Earth was 139.19 million km (86.49 million mi; 0.9304 AU) while the distance between Mars and the Moon was 139.58 million km (86.73 million mi; 0.9330 AU). Interestingly enough, this is what an observer would see from the surface of Mars using a telescope, whereas a naked-eye observer would simply see a single point of light.
Usually, the Earth and Moon are visible as two separate points of light, but at this point in the Moon’s orbit they were too close to resolve with the naked eye from Mars. If you look closely at Earth, you can just make out the shape of South America.
The picture above was snapped by the Mars Express’s High Resolution Stereo Camera (HRSC) on the ESA’s Mars Express probe. It was also taken in 2003, and is similar in that it shows the Earth and Moon together. However, in this image, we see the two bodies at different points in their orbit – which is why the Moon looks like its farther away. Interestingly enough, this image was actually part of the first data sets to be sent by the spacecraft.
The next orbiter to capture an image of Earth from Mars was the Mars Reconnaissance Orbiter (MRO), which was launched in August of 2005 and attained Martian orbit on March 10th, 2006. When the probe reached Mars, it joined five other active spacecraft that were either in orbit or on the surface, which set a record for the most operational spacecraft in the vicinity of Mars at the same time.
In the course of its mission – which was to study Mars’ surface and weather conditions, as well as scout potential landing sites – the orbiter took many interesting pictures. The one below was taken on Oct. 3rd, 2007, which showed the Earth and the Moon in the same frame.
Pictures from the Surface:
As noted already, pictures of Earth have also been taken by robotic missions to the surface of Mars. This has been the case for as long as space agencies have been sending rovers or landers that came equipped with mobile cameras. The earliest rovers to reach the surface – Mars 2 and Mars 3– were both sent by the Soviets.
However, it was not until early March of 2004, while taking photographs of the Martian sky, that the Spirit rover became the first to snap a picture of Earth from the surface of another planet. This image was caught while the rover was attempting to observe Mars’ moon Deimos making a transit of the Sun (i.e. a partial eclipse).
This is something which happens quite often given the moon’s orbital period of about 30 hours. However, on this occasion, the rover managed to also capture a picture of distant Earth, which appeared as little more than a particularly bright star in the night sky.
The next rover to snap an image of Earth from the Martian surface was Curiosity, which began sending back many breathtaking photos even before it landed on Aug. 6th, 2012. And on Jan. 31st, 2014 – almost a year and a half into its mission – the rover managed to capture an image of both Earth and the Moon in the night sky.
In the image (seen below), Earth and the Moon are just visible as tiny dots to the naked eye – hence the inset that shows them blown up for greater clarity. The distance between Earth and Mars when Curiosity took the photo was about 160 million km (99 million mi).
Earth has been photographed from Mars several times now over the course of the past few decades. Each picture has been a reminder of just how far we’ve come as a species. It also provides us with a preview of what future generations may see when looking out their cabin window, or up at the night sky from other planets.
Mars’ natural satellites – Phobos and Deimos – have been a mystery since they were first discovered. While it is widely believed that they are former asteroids that were captured by Mars’ gravity, this remains unproven. And while some of Phobos’ surface features are known to be the result of Mars’ gravity, the origin of its linear grooves and crater chains (catenae) have remained unknown.
But thanks to a new study by Erik Asphaug of Arizona State University and Michael Nayak from the University of California, we may be closer to understanding how Phobos’ got its “groovy” surface. In short, they believe that re-accretion is the answer, where all the material that was ejected when meteors impacted the moon eventually returned to strike the surface again.
Naturally, Phobos’ mysteries extend beyond its origin and surface features. For instance, despite being much more massive than its counterpart Deimos, it orbits Mars at a much closer distance (9,300 km compared to over 23,000 km). It’s density measurements have also indicated that the moon is not composed of solid rock, and it is known to be significantly porous.
Because of this proximity, it is subject to a lot of tidal forces exerted by Mars. This causes its interior, a large portion of which is believed to consist of ice, to flex and stretch. This action, it has been theorized, is what is responsible for the stress fields that have been observed on the moon’s surface.
However, this action cannot account for another common feature on Phobos, which are the striation patterns (aka. grooves) that run perpendicular to the stress fields. These patterns are essentially chains of craters that typically measure 20 km (12 mi) in length, 100 – 200 meters (330 – 660 ft) in width, and usually 30 m (98 ft) in depth.
In the past, it was assumed that these craters were the result of the same impact that created Stickney, the largest impact crater on Phobos. However, analysis from the Mars Express mission revealed that the grooves are not related to Stickney. Instead, they are centered on Phobos’ leading edge and fade away the closer one gets to its trailing edge.
For the sake of their study, which was recently published in Nature Communications, Asphaug and Nayak used computer modeling to simulate how other meteoric impacts could have created these crater patterns, which they theorized were formed when the resulting ejecta circled back and impacted the surface in other locations.
As Dr. Asphaug told Universe Today via email, their work was the result of a meeting of minds that spawned an interesting theory:
“Dr. Nayak had been studying with Prof. Francis Nimmo (of UCSC), the idea that ejecta could swap between the Martian moons. So Mikey and I met up to talk about that, and the possibility that Phobos could sweep up its own ejecta. Originally I had been thinking that seismic events (triggered by impacts) might cause Phobos to shed material tidally, since it’s inside the Roche limit, and that this material would thin out into rings that would be reaccreted by Phobos. That still might happen, but for the prominent catenae the answer turned out to be much simpler (after a lot of painstaking computations) – that crater ejecta is faster than Phobos’ escape velocity, but much slower than Mars orbital velocity, and much of it gets swept up after several co-orbits about Mars, forming these patterns.”
Basically, they theorized that if a meteorite stuck Phobos in just the right place, the resulting debris could have been thrown off into space and swept up later as Phobos swung back around mars. Thought Phobos does not have sufficient gravity to re-accrete ejecta on its own, Mars’ gravitational pull ensures that anything thrown off by the moon will be pulled into orbit around it.
Once this debris is pulled into orbit around Mars, it will circle the planet a few times until it eventually falls into Phobos’ orbital path. When that happens, Phobos will collide with it, triggering another impact that throws off more ejecta, thus causing the whole process to repeat itself.
In the end, Asphaug and Nayak concluded that if an impact hit Phobos at a certain point, the subsequent collisions with the resulting debris would form a chain of craters in discernible patterns – possibly within days. Testing this theory required some computer modeling on an actual crater.
Using Grildrig (a 2.6 km crater near Phobos’ north pole) as a reference point, their model showed that the resulting string of craters was consistent with the chains that have been observed on Phobos’ surface. And while this remains a theory, this initial confirmation does provide a basis for further testing.
“The initial main test of the theory is that the patterns match up, ejecta from Grildrig for example,” said Asphaug. “But it’s still a theory. It has some testable implications that we’re now working on.”
In addition to offering a plausible explanation of Phobos’ surface features, their study is also significant in that it is the first time that sesquinary craters (i.e. craters caused by ejecta that went into orbit around the central planet) were traced back to their primary impacts.
In the future, this kind of process could prove to be a novel way to assess the surface characteristics of planets and other bodies – such as the heavily cratered moons of Jupiter and Saturn. These findings will also help us to learn more about Phobos history, which in turn will help shed light on the history of Mars.
“[It] expands our ability to make cross-cutting relationships on Phobos that will reveal the sequence of geologic history,” Asphaug added. “Since Phobos’ geologic history is slaved to the tidal dissipation of Mars, in learning the timescale of Phobos geology we learn about the interior structure of Mars”
And all of this information is likely to come in handy when it comes time for NASA to mount crewed missions to the Red Planet. One of the key steps in the proposed “Journey to Mars” is a mission to Phobos, where the crew, a Mars habitat, and the mission’s vehicles will all be deployed in advance of a mission to the Martian surface.
Learning more about the interior structure of Mars is a goal shared by many of NASA’s future missions to the planet, which includes NASA’s InSight Lander (schedules for launch in 2018). Shedding light on Mars geology is expected to go a long way towards explaining how the planet lost its magnetosphere, and hence its atmosphere and surface water, billions of years ago.
Strange plumes in Mars’ atmosphere first recorded by amateur astronomers four year ago have planetary scientists still scratching their heads. But new data from European Space Agency’s orbiting Mars Express points to coronal mass ejections from the Sun as the culprit.
On two occasions in 2012 amateurs photographed cloud-like features rising to altitudes of over 155 miles (250 km) above the same region of Mars. By comparison, similar features seen in the past haven’t exceeded 62 miles (100 km). On March 20th of that year, the cloud developed in less than 10 hours, covered an area of up to 620 x 310 miles (1000 x 500 kilometers), and remained visible for around 10 days.
Back then astronomers hypothesized that ice crystals or even dust whirled high into the Martian atmosphere by seasonal winds might be the cause. However, the extreme altitude is far higher than where typical clouds of frozen carbon dioxide and water are thought to be able to form.
Indeed at those altitudes, we’ve entered Mars’ ionosphere, a rarified region where what air there is has been ionized by solar radiation. At Earth, charged particles from the Sun follow the planet’s global magnetic lines of force into the upper atmosphere to spark the aurora borealis. Might the strange features observed be Martian auroras linked to regions on the surface with stronger-than-usual magnetic fields?
Once upon a very long time ago, Mars may have had a global magnetic field generated by electrical currents in a liquid iron-nickel core much like the Earth’s does today. In the current era, the Red Planet has only residual fields centered over regions of magnetic rocks in its crust.
Instead of a single, planet-wide field that funnels particles from the Sun into the atmosphere to generate auroras, Mars is peppered with pockets of magnetism, each potentially capable of connecting with the wind of particles from the Sun to spark a modest display of the “northern lights.” Auroras were first discovered on Mars in 2004 by the Mars Express orbiter, but they’re faint compared to the plumes, which were too bright to be considered auroras.
Still, this was a step in the right direction. What was needed was some hard data of a possible Sun-Earth interaction which scientists ultimately found when they looked into plasma and solar wind measurements collected by Mars Express at the time. David Andrews of the Swedish Institute of Space Physics, lead author of a recent paper reporting the Mars Express results, found evidence for a large coronal mass ejection or CME from the Sun striking the martian atmosphere in the right place and at around the right time.
CMEs are enormous explosions of hot solar plasma — a soup of electrons and protons — entwined with magnetic fields that blast off the Sun and can touch off geomagnetic storms and auroras when they encounter the Earth and other planets.
“Our plasma observations tell us that there was a space weather event large enough to impact Mars and increase the escape of plasma from the planet’s atmosphere,” said Andrews. Indeed, the plume was seen along the day–night boundary, over a region of known strong crustal magnetic fields.
But again, a Mars aurora wouldn’t be expected to shine so brightly. That’s why Andrews thinks that the CME prompted a disturbance in the ionosphere large enough to affect dust and ice grains below:
“One idea is that a fast-traveling CME causes a significant perturbation in the ionosphere resulting in dust and ice grains residing at high altitudes in the upper atmosphere being pushed around by the ionospheric plasma and magnetic fields, and then lofted to even higher altitudes by electrical charging,” according to Andrews.
With enough dust and ice twinkling high above the planet’s surface, it might be possible for observers on Earth to see the result as a wispy plume of light. Plumes appear to be rare on Mars as a search through the archives has revealed. The only other, seen by the Hubble Space Telescope in May 1997, occurred when a CME was hitting the Earth at the same time. Unfortunately, there’s no information from Mars orbiters at the time about its effect on that planet.
Observers on Earth and orbiters zipping around the Red Planet continue to monitor Mars for recurrences. Scientists also plan to use the webcam on Mars Express for more frequent coverage. Like a dog with a bone, once scientists get a bite on a tasty mystery, they won’t be letting go anytime soon.
Scene from ‘The Martian’ starring Matt Damon as NASA astronaut Mark Watney contemplating magnificent panoramic vista while stranded alone on Mars.
Credits: 20th Century Fox
See real Martian maps and flyover video from DLR and NSA below
Story/imagery updated[/caption]
Go now and experience Hollywood’s blockbuster new space epic ‘The Martian’ helmed by world renowned director Ridley Scott and starring Matt Damon as the protagonist, NASA astronaut Mark Watney. And you can follow Watney’s dramatic fictional path across the Red Planet in newly released real photos and a flyover video of the region, from DLR and NASA, as it looks today.
‘The Martian’ is a mesmerizingly enjoyable cinematic triumph for everyone that’s all about science, space exploration and one man’s struggle to survive while left totally isolated on the Red Planet in the face of seemingly insurmountable odds – relying on his wits alone to endure “on a planet where nothing grows” while hoping somehow for a rescue by NASA four years in the future.
The movie combines compelling and plausible storytelling with outstanding special effects that’s clearly delighting huge audiences worldwide with a positive and uplifting view of what could be achieved in the future – if only we really put our minds to it!
Based on the bestselling book by Andy Weir, ‘The Martian’ movie from 20th Century Fox tells the spellbinding story of how NASA astronaut Mark Watney is accidentally stranded on the surface of Mars during the future Ares 3 manned expedition in 2035, after a sudden and unexpectedly fierce dust storm forces the rest of the six person crew – commanded by Jessica Chastain as Commander Lewis – to quickly evacuate after they believe he is dead.
Now you can follow the fictional exploits of Mark Watney’s stunningly beautiful trail across the real Mars through a set of newly released maps, imagery and a 3D video created by the DLR, the German Aerospace Agency, and NASA – and based on photos taken by the European Space Agency’s Mars Express orbiter and NASA’s Mars Reconnaissance Orbiter (MRO).
DLR’s stunning 3D overflight video sequence was created from a dataset of 7300 stereo images covering roughly two-and-a-half million square kilometres of precisely mapped Martian landscape captured over the past 12 years by Mars Express High Resolution Stereo Camera (HRSC). The electric score is by Stephan Elgner.
Video Caption: Following the path of The Martian – video generated using images acquired by the Mars Express orbiter. Scientists from German Aerospace Center, DLR– who specialise in producing highly accurate topographical maps of Mars – reconstructed Watney’s route using stereo image data acquired by the High Resolution Stereo Camera on board European Space Agency’s #MarsExpress spacecraft. They then compiled this data into a video that shows the spectacular landscape that the protagonist would see ‘in the future’ on his trek from Ares 3 at Acidalia Planitia/Chryse Planitia to Ares 4 at Schiaparelli Crater. Credit: DLR/ESA
Ridley Scotts ‘The Martian’ takes place mostly on the surface of the Red Planet and is chock full of breathtakingly beautiful panoramic vistas. In the book you can only imagine Mars. In the movie Scott’s talents shine as he immerses you in all the action on the alien world of Mars from the opening scene.
Starting with the landing site for Watney’s Ares 3 mission crew at Acidalia Planitia, the book and movie follows his triumphs and tribulations, failures and successes as he logically solves one challenging problem after another – only to face increasingly daunting and unexpected hurdles as time goes by and supplies run low.
The DLR route map shows a real topographic view of Watney’s initial journey back and forth from the fictional Ares 3 landing site to the actual landing site of NASA’s 1997 Mars Pathfinder lander and Sojourner rover mission at the mouth of Ares Vallis.
The map continues with Watney’s months-long epic trek to the fictional landing site of Ares 4 Mars Ascent Vehicle (MAV) spacecraft at Schiaparelli Crater, by way of Marth Valles and other Martian landmarks, craters and valleys.
At the request of Andy Weir, the HiRISE camera on NASA’s MRO orbiter took photos of the Martian plain at the Ares 3 landing site in Acidalia Planitia, which is within driving distance from the Pathfinder lander and Sojourner rover in the book and movie.
The Martian is all about how Watney uses his botany, chemistry and engineering skills to “Science the sh** out of it” to grow food and survive until the hoped for NASA rescue.
Learning how to live off the land will be a key hurdle towards enabling NASA’s real strategy for long term space voyages on a ‘Journey to Mars’ and back.
‘The Martian’ is a must see movie that broadly appeals to space enthusiasts and general audiences alike who can easily identify with Watney’s ingenuity and will to live.
Since its worldwide premiere on Oct. 2, ‘The Martian’ has skyrocketed to the top of the US box office for the second weekend in a row, hauling in some $37.3 million. The total domestic box office receipts now top $108 million and rockets to over $228 million worldwide in the first 10 days alone.
I absolutely loved ‘The Martian’ when I first saw the movie on opening weekend. And enjoyed it even more the second time, when I could pick up a few details I missed the first time around.
The movie begins as the crew evacuates after they believe Watney was killed by the dust storm. Watney actually survived the storm but lost contact with NASA. The film recounts his ingenious years long struggle to survive, figure out how to tell NASA he is alive and send a rescue crew before he starves to death on a planet where nothing grows. Watney’s predicament is a survival lesson to all including NASA.
‘The Martian’ was written by Andy Weir in 2010 and the film could well break the October movie box office record currently held by ‘Gravity.’
The movie closely follows the book, which I highly recommend you read at some point.
By necessity, the 2 hour 20 minute movie cannot capture every event in the book. So there is an abbreviated sense of Watney’s detailed science to survive and lengthy overland trips.
All the heroics and difficulties in traveling to Pathfinder and back and getting communications started, as well as the final month’s long journey to Schiaparelli crater are significantly condensed, but captured in spirit.
The Martian is brilliant and intelligent and rivals Stanley Kubrik’s space epic ‘2001: A Space Odyssey’ as one of the top movies about humanities space exploration quest.
The one big science inaccuracy takes place right at the start with the violent Martian dust storm.
On Mars the atmosphere is so thin that the winds would not be anywhere near as powerful or destructive as portrayed. This is acknowledged by Weir and done for dramatic license. We can look past that since the remainder of the tale portrays a rather realistic architectural path to Mars and vision of how scientists and engineers think. Plus the dust storms can in fact kick up tremendous amounts of particles that significantly block sunlight from impinging on solar energy generating panels.
Personally I can’t wait for the ‘Directors Cut’ with an added 30 to 60 minutes of scenes that were clearly filmed – but not included in the original theatrical release.
THE MARTIAN features a star studded cast that includes Matt Damon, Jessica Chastain, Kristen Wiig, Kate Mara, Michael Pena, Jeff Daniels, Chiwetel Ejiofor, and Donald Glover.
“NASA has endorsed “The Martian’” Jim Green, NASA’s Director of Planetary Sciences, told Universe Today. Green served as technical consultant on the film.
The DLR film was created by a team led by Ralf Jaumann from the DLR Institute of Planetary Research, Principal Investigator for HRSC. He believes that producing the overflight video was not just a gimmick for a science fiction film:
“Mars generates immense fascination, and our curiosity continues to grow! Many people are interested in our research, and young people in particular want to know what it is really like up there, and how realistic the idea that one day people will leave their footprints on the surface of Mars truly is. The data acquired by HRSC shows Mars with a clarity and detail unmatched by any other experiment. Only images acquired directly on the surface, for instance by rovers like Curiosity, are even closer to reality, but they can only show a small part of the planet. Thanks to this animation, we have even noticed a few new details that we had not seen in a larger spatial context. That is why we made the film – it helps everyone see what it would be like for Watney to travel through these areas… the clouds were the only creative touches we added, because, fortunately, they do not appear in the HRSC data,” according to a DLR statement.
Here’s the second official trailer for The Martian:
As a scientist and just plain Earthling, my most fervent hope is that ‘The Martian’ will inspire our young people to get interested in all fields of science, math and engineering and get motivated to become the next generation of explorers – here on Earth and beyond to the High Frontier to benefit all Mankind.
Stay tuned here for Ken’s continuing Earth and planetary science and human spaceflight news.
“Thousands of meteors per hour would have been visible — truly astounding to the human eye.” That’s Nick Schneider’s description of what you and I would have seen standing on Mars during Comet Siding Spring’s close flyby last month. “It would have been really mind-blowing,” he added. Schneider is instrument lead for MAVEN’s Imaging Ultraviolet Spectrograph (IUVS).
He and a group of scientists who work as lead investigators for instruments on the MAVEN and Mars Reconnaissance Orbiter (MRO) spacecraft shared the latest results from the comet flyby during a media teleconference earlier today. There were many surprises. Would we expect anything less from a comet?
Here’s a summary of the results:
A very dusty ice ball – The comet’s dust tail and the amount of dust in its coma were much larger than expected, prompting Jim Green, director of NASA’s Planetary Science Division in Washington, to remark: “It makes me very happy we hid them (the spacecraft) on the backside of Mars. That really saved them.” Siding Spring dumped several tons of fine dust into the Martian atmosphere prompting a spectacular meteor shower and possibly causing a yellow, twilight afterglow above the Curiosity landing site from vaporizing sodium atoms contained in the minerals. That, and dust in the mid-levels of the atmosphere at the time contributed to the rover’s difficulty in getting good photos of the comet itself. Scientists are still examining the images.
Chemistry of Mars’ atmosphere changed – Dust vaporized in the intense meteor shower produced a striking increase in the amount of magnesium, iron and others metals in Mars’ upper atmosphere. “We were pressed back in our chairs,” said Mike Schneider. The bombardment created a temporary new layer of comet-tainted air and may have acted as condensation nuclei for the formation of high-altitude clouds. MAVEN’s Neutral Gas and Ion Mass Spectrometer (NGIMS) recorded huge spikes in the levels of eight different metals during the comet’s passage and then trailed off a day or so later. “They came to MAVEN as a free sample from no less than an Oort Cloud comet,” said Mehdi Benna, instrument scientist for MAVEN’s Neutral Gas and Ion Mass Spectrometer.
Flaming comet dust creates new ionospheric layer – Comet dust slamming into the atmosphere at 125,000 mph (56 km/sec) knocked electrons loose from atoms in the thin Martian air 50-60 miles (80-100 km) high, ionizing them and creating a very dense ionization layer in the planet’s lower ionosphere seven hours after the comet’s closest approach. Normally, Mars ionosphere is only seen on the dayside of the planet, but even when the MARSIS instrumenton Mars Express beamed radio waves through the atmosphere on the nightside of the planet, it picked up a very strong signal.
Nucleus spins once during your work day – Comet Siding Spring’s icy core spins once every 8 hours and its irregular shape causes strong variations in the comet’s brightness. The comet’s size appears less certain – at least for the moment – with estimates anywhere between a few hundred meters to 2 km (1.2 miles). More analysis on images taken by MRO’s HiRISE camera should narrow that number soon.
Dust motes of many sizes – Color variations across Siding Spring’s coma seen by Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) indicate it’s releasing dust particles of different sizes – big and little.
The scientists involved in the encounter couldn’t be happier with how the instruments functioned and the amount of hard data returned. Said Jim Green: “We are so lucky to observe this once-in-a-lifetime event.” How true when you consider that it takes about 8 million years for a comet from the Oort Cloud, that vast reservoir of frozen comets extending nearly a light year from the Sun, to get here in the first place. Nick Schneider put it another way:
“Not only is this a free sample of the Oort Cloud in Mars’ atmosphere, but it gives us a chance to learn more about Mars itself.”
If you’d like to listen in to the hour-long teleconference at any time, it’ll be up for the next week or so HERE.
It was 20 years ago this past July when images of Jupiter being pummeled by a comet caught the world’s attention. Comet Shoemaker-Levy 9 had flown too close to Jupiter. It was captured by the giant planet’s gravity and torn into a string of beads. One by one the comet fragments impacted Jupiter — leaving blemishes on its atmosphere, each several times larger than Earth in size.
Until that event, no one had seen a comet impact a planet. Now, Mars will see a very close passage of the comet Siding Spring on October 19th. When the comet was first discovered, astronomers quickly realized that it was heading straight at Mars. In fact, it appeared it was going to be a bulls-eye hit — except for the margin of error in calculating a comet’s trajectory from 1 billion kilometers (620 million miles, 7 AU) away.
It took several months of analysis for a cataclysmic impact on Mars to be ruled out. So now today, Mars faces just a cosmic close shave. But this comet packs enough energy that an impact would have globally altered Mars’ surface and atmosphere.
So what should we Earthlings gather from this and other events like it? Are we next? Why or why not should we be prepared for impacts from these mile wide objects?
For one, ask any dinosaur and you will have your answer.
One can say that Mars was spared as were the five orbiting spacecraft from India (Mars Orbiter Mission), the European Union (Mars Express) and the United States (MOD, MRO, MAVEN). We have Scottish-Australian astronomer Robert McNaught to thank for discovering the comet on January 3, 2013, using the half meter (20 inch) Uppsala Southern Schmidt Telescope at Siding Spring, Australia.
Initially the margin of error in the trajectory was large, but a series of observations gradually reduced the error. By late summer 2014, Mars was in the clear and astronomers could confidently say the comet would pass close but not impact. Furthermore, as observations accumulated — including estimates of the outpouring of gases and dust — comet Siding Spring shrunk in size, i.e. the estimates of potentially tens of kilometers were down to now 700 meters (4/10th of a mile) in diameter. Estimates of the gas and dust production are low and the size of the tail and coma — the spherical gas cloud surrounding the solid body — are small and only the outer edge of both will interact with Mars’ atmosphere.
Yet, this is a close call for Mars. We could not rule out a collision for over six months. While this comet is small, it is moving relative to Mars at a speed of 200,000 kilometers/hour (125,000 mph, 56 km/sec). This small body packs a wallop. From high school science or intro college Physics, many of us know that the kinetic energy of an object increases by the square of the velocity. Double the velocity and the energy of the object goes up by 4, increase by 3 – energy increases by 9.
So the close shave for Mars is yet another wake up call for the “intelligent” space faring beings of the planet Earth. A wake up call because the close passage of a comet could have just as easily involved Earth. Astronomers would have warned the world of a comet heading straight for us, one that could wipe out 70% of all life as happened 65 million years ago to the dinosaurs. Replace dinosaur with humans and you have the full picture.
Time would have been of the essence. The space faring nations of the world — those of the EU, and Russia, the USA, Japan and others — would have gathered and attempted to conceive some spacecrafts with likely nuclear weapons that could be built and launched within a few months. Probably several vehicles with weapons would be launched at once, leaving Earth as soon as possible. Intercepting a comet or asteroid further out would give the impulse from the explosions more time to push the incoming body away from the Earth.
There is no way that humanity could sit on their collective hands and wait for astronomers to observe and measure for months until they could claim that it would just be a close call for Earth. We could imagine the panic it would cause. Recall the scenes from Carl Sagan’s movie Contact with people of every persuasion expressing at 120 decibels their hopes and fears. Even a small comet or asteroid, only a half kilometer – a third of a mile in diameter would be a cataclysmic event for Mars or Earth.
But yet, in the time that has since transpired from discovery of the comet Siding Spring (1/3/2013), the Chelyabinsk asteroid (~20 m/65 ft) exploded in an air burst that injured 1500 people in Russia. The telescope that discovered Comet Siding Spring was decommissioned in late 2013 and the Southern Near-Earth Object Survey was shutdown. This has left the southern skies without a dedicated telescope for finding near-Earth asteroids. And proposals such as the Sentinel project by the B612 Foundation remain underfunded.
We know of the dangers from small celestial bodies such as comets or asteroids. Government organizations in the United States and groups at the United Nations are discussing plans. There is plenty of time to find and protect the Earth but not necessarily time to waste.
NASA’s planetary senior review panel harshly criticized the scientific return of the Curiosity rover in a report released yesterday (Sept. 3), saying the mission lacks focus and the team is taking actions that show they think the $2.5-billion mission is “too big to fail.”
While the review did recommend the mission receive more funding — along with the other six NASA extended planetary missions being scrutinized — members recommended making several changes to the mission. One of them would be reducing the distance that Curiosity drives in favor of doing more detailed investigations when it stops.
The role of the senior review, which is held every two years, is to help NASA decide what money should be allocated to its extended missions. This is important, because the agency (as with many other departments) has limited funds and tries to seek a balance between spending money on new missions and keeping older ones going strong.
Engineering acumen means that many missions are now operating well past their expiry dates, such as the Cassini orbiter at Saturn and the Opportunity rover on Mars. In examining the seven missions being reviewed, the panel did recommend keeping funding for all, but said that 4/7 are facing significant problems.
In the case of Curiosity, the panel called out principal investigator John Grotzinger for not showing up in person on two occasions, preferring instead to interact by phone. The review also said there is a “lack of science” in its extended mission proposal with regard to “scientific questions to be answered, testable hypotheses, and proposed measurements and assessment of uncertainties and limitations.”
Other concerns were the small number of samples over the prime and extended missions (13, a “poor science return”), and a lack of clarity on how the ChemCam and Mastcam instruments will play into the extended mission. Additionally, the panel expressed concern that NASA would cut short its observations of clays (which could help answer questions of habitability) in favor of heading to Mount Sharp, the mission’s ultimate science destination.
“In summary, the Curiosity … proposal lacked scientific focus and detail,” the panel concluded, adding in its general recommendations for the reviews that principal investigators must be present to avoid confusion while answering questions. The other missions facing concern from the panel included the Lunar Reconnaissance Orbiter, Mars Express and Mars Odyssey.
LRO: Its extended mission (the second) is supposed to look at how the moon’s surface, subsurface and exosphere changes through processes such as meteorites and interaction with space. The panel was concerned with a “lack of detail” in the proposal and in answers to follow-up questions. The panel also recommended turning off certain instruments “at the end of their useful science mission”.
Mars Express: The extended mission is focusing on the ionosphere and atmosphere as well as the planet’s surface and subsurface. Concerns were raised about matters such as why funding is needed to calibrate its high-resolution stereo camera after 11 years — especially given the instrument has been rarely cited in published journal reports lately — and how people involved in the extended mission would meet the goals. The panel also saw a “lack of communication” in the team.
Mars Odyssey: If approved, the spacecraft will move to the day/night line of Mars to look at the planet’s radiation, gamma rays, distribution of water/carbon dioxide/dust in the atmosphere, and the planet’s surface. The panel, however, said there are no “convincing arguments” as to how the new science relates to the Decadal Survey objectives for planetary science. Odyssey, which is in its 11th year, may also be nearing the end of its productive lifespan given fewer publications using its data in recent years, the panel said.
The panel also weighed in on the success of the Cassini and Opportunity missions:
Cassini received the highest rating — “Excellent” — due to its scientific merit, the only mission this time around to do so. The panel was particularly excited about seasonal changes that will be seen on Titan in the coming years, as well as measurements of Saturn’s rings and magnetosphere and its icier moons (such as Enceladus). The spacecraft is noted to be in good condition and the new mission will be a success because of “the unique aspect of the new observations.”
Opportunity, which is more than 10 years into its Mars exploration, is still “in sufficiently good condition” to do science, although the panel raised concerns about software and communication problems. The panel, however, said more time with the rover would allow it to look for evidence of past water on Mars that would not be visible from orbit — even though it’s unclear if phyllosilicates around its current location (Endeavour crater) are from the Noachian period, the earliest period in Mars’ history.
The panel is just one step along the road to figuring out how NASA chooses to spend its money in the coming years. Funding availability depends on how much money Congress allocates to the agency.
Did that impact 4.1 billion years ago ever leave a scar! Here, a Mars Express photo from late 2013 (and just highlighted now) shows off craters in Hellas Basin, which was formed when the planets in our young Solar System were under intense bombardment from leftover remnants.
But over time, wind and erosion on Mars have changed the nature of this basin, the German Space Agency explained.
“Over time, the interior of Hellas Planitia has been greatly altered by geological processes,” the German Space Agency stated.
“The wind has blown dust into the basin, glaciers and streams have transported and deposited sediment, and volcanoes have built up layers of low-viscosity lava on the floor of Hellas. Despite its exposure to erosion and coverage by deposits for a long period of time, it is the best-preserved large impact basin on Mars.”
What’s more, Hellas is so deep (four kilometers or 2.5 miles) that scientists suspect water could be stable near the bottom of the pit. That’s because the combination of pressure and temperature there could possibly support water for some time, which is different from much of the rest of Mars where the pressure is too thin for water to do much but evaporate.
Such great heights! A mountain chain peeks in the background of this new view of Hellas Basin, based on information taken by a European spacecraft circling the Red Planet.
Beyond the pretty picture is a tale of how snow behaved on the Martian surface, according to the European Space Agency. The vast basin is about half the size of Brazil.
The wrinkled view of that crater in front is a product of snowing and freezing that took place when the Martian surface was wetter, ESA said.
“During this period, snow fell and covered the surface and later moved downhill into the crater. Once inside the crater, the snow became trapped and soon covered by surface dust, before compacting to form ice. The number of concentric lines indicates many cycles of this process and it is possible that craters like these may still be rich in ice hidden beneath just tens of metres of surface debris.”
Additionally, the high hill chain in the back (called Hellespontus Montes) is a remnant of how Hellas basin was formed, the agency said.
“This feature is a product of the final stages of the formation of the vast Hellas impact basin itself, most likely as the basin walls – which were first pushed outwards by the extraordinary forces at work during the formation of the basin – later collapsed and sank inwards to create the observed stair-stepped shape.”
The image was taken by ESA’s Mars Express spacecraft, which is just one of several robotic emissaries circling the Red Planet.
NASA’s decade old Opportunity rover has reached a long sought after region of aluminum-rich clay mineral outcrops at a new Endeavour crater ridge now “named ‘Pillinger Point’ after Colin Pillinger the Principal Investigator for the [British] Beagle 2 Mars lander”, Prof. Ray Arvidson, Deputy Principal Investigator for the rover, told Universe Today exclusively. See above the spectacular panoramic view from ‘Pillinger Point’ – where ancient water once flowed billions of year ago.
The Beagle 2 lander was built to search for signs of life on Mars.
The Mars Exploration Rover (MER) team named the noteworthy ridge in honor of Prof. Colin Pillinger – a British planetary scientist at the Open University in Milton Keynes, who passed away at the age of 70 on May 7, 2014.
‘Pillinger Point’ is a scientifically bountiful place possessing both clay mineral outcrops and mineral veins where “waters came up through the cracks”, Arvidson explained to me.
Since water is a prerequisite for life as we know it, this is a truly fitting tribute to name Opportunity’s current exploration site ‘Pillinger Point’ after Prof. Pillinger.
See our new photo mosaic above captured by Opportunity peering out from ‘Pillinger Point’ ridge on June 5, 2014 (Sol 3684) and showing a panoramic view around the eroded mountain ridge and into vast Endeavour crater.
The gigantic crater spans 14 miles (22 kilometers) in diameter.
See below our Opportunity 10 Year traverse map showing the location of Pillinger Point along the segmented rim of Endeavour crater.
Pillinger Point is situated south of Solander Point and Murray Ridge along the western rim of Endeavour in a region with caches of clay minerals indicative of an ancient Martian habitable zone.
For the past several months, the six wheeled robot has been trekking southwards from Solander towards the exposures of aluminum-rich clays – now named Pillinger Point- detected from orbit by the CRISM spectrometer aboard NASA’s powerful Martian ‘Spysat’ – the Mars Reconnaissance Orbiter (MRO) – while gathering context data at rock outcrops along the winding way.
“We are about 3/5 of the way along the outcrops that show an Al-OH [aluminum-hydroxl] montmorillonite [clay mineral] signature at 2.2 micrometers from CRISM along track oversampled data,” Arvidson told me.
“We have another ~160 meters to go before reaching a break in the outcrops and a broad valley.”
The rover mission scientists ultimate goal is travel even further south to ‘Cape Tribulation’ which holds a motherlode of the ‘phyllosilicate’ clay minerals based on extensive CRISM measurements accomplished earlier at Arvidson’s direction.
“The idea is to characterize the outcrops as we go and then once we reach the valley travel quickly to Cape Tribulation and the smectite valley, which is still ~2 km to the south of the present rover location,” Arvidson explained.
Mars Express and Beagle 2 were launched in 2003, the same year as NASA’s twin rovers Spirit and Opportunity, on their interplanetary voyages to help unlock the mysteries of Mars potential for supporting microbial life forms.
Pillinger was the driving force behind the British built Beagle 2 lander which flew to the Red Planet piggybacked on ESA’s Mars Express orbiter. Unfortunately Beagle 2 vanished without a trace after being deployed from the orbiter on Dec. 19, 2003 with an expected air bag assisted landing on Christmas Day, Dec. 25, 2003.
In an obituary by the BBC, Dr David Parker, the chief executive of the UK Space Agency, said that Prof. Pillinger had played a critical role in raising the profile of the British space programme and had inspired “young people to dream big dreams”.
During his distinguished career Pillinger also analyzed lunar rock samples from NASA’s Apollo moon landing missions and worked on ESA’s Rosetta mission.
“It’s important to note that Colin’s contribution to planetary science goes back to working on Moon samples from Apollo, as well as his work on meteorites,” Dr Parker told the BBC.
Today, June 16, marks Opportunity’s 3696th Sol or Martian Day roving Mars – compared to a warranty of just 90 Sols.
So far she has snapped over 193,400 amazing images on the first overland expedition across the Red Planet.
Her total odometry stands at over 24.51 miles (39.44 kilometers) since touchdown on Jan. 24, 2004 at Meridiani Planum.
Meanwhile on the opposite side of Mars, Opportunity’s younger sister rover Curiosity is trekking towards gigantic Mount Sharp after drilling into her 3rd Red Planet rock at Kimberley.
Stay tuned here for Ken’s continuing Curiosity, Opportunity, Orion, SpaceX, Boeing, Orbital Sciences, MAVEN, MOM, Mars and more planetary and human spaceflight news.