NASA has shared Opportunity’s final photograph from the surface of Mars. The rover’s final resting place is in Endeavour Crater, and barring any statistically unlikely event, it will sit there for centuries, millennia, or even longer. And instead of a tombstone, we have this final image.
In 2012, NASA’s Curiosity rover landed in the Gale Crater on Mars and began exploring for clues about the planet’s past and subsequent evolution. Since 2014, it has been investigating Mount Sharp (aka. Aeolis Mons) – the central peak within Mars’ Gale Crater – in the hopes of learning more about Mars’ warm, watery past (and maybe find signs of past life!)
On February 15th of this year (Sol 2320), Curiosity gave mission controllers a bit of a scare when it suffered a technical glitch and automatically entered safe mode. Luckily, as of Thursday, Feb. 28th, Curiosity’s science team reported that after getting the rover back online and running a series of checks, the rover is in good shape and ready to resume normal science operations.
NASA’s Opportunity rover has reached the end of its life. Initially designed to last 90 days, and to travel only 1000 meters (1100 yards), the rover spent almost 15 years exploring the surface of Mars. During that time, it travelled more than 45 kilometers (28 miles.)
Could this be the end of the Opportunity rover? There’s been no signal from the rover since last summer, when a massive global dust storm descended on it. But even though the craft has been silent and unreachable for six-and-a-half months, NASA hasn’t given up.
When Opportunity landed at Meridiani Planum on Mars in January 2004, it’s planned mission length was only 90 days. Since that day, which seems so long ago now, 15 years have passed, and over one billion people have been born on Earth. Six months ago, the rover stopped working, maybe for good. So by every measure, Opportunity has been a stunning success.
Welcome to the 575th Carnival of Space! The Carnival is a community of space science and astronomy writers and bloggers, who submit their best work each week for your benefit. We have a fantastic roundup today including news from the IAU, so now, on to this week’s worth of stories! Continue reading “Carnival of Space #575”
Martian dust storms are a pretty common occurrence, and generally happen whenever the southern hemisphere is experiencing summer. Though they can begin quite suddenly, these storms typically stay contained to a local area and last only about a few weeks. However, on occasion, Martian dust storms can grow to become global phenomena, covering the entire planet.
One such storm began back in May, starting in the Arabia Terra region and then spreading to become a planet-wide dust storm within a matter of weeks. This storm caused the skies over the Perseverance Valley, where the Opportunity rover is stationed, to become darkened, forcing the rover into hibernation mode. And while no word has been heard from the rover, NASA recently indicated that the dust storm will dissipate in a matter of weeks.
The update was posted by NASA’s Mars Exploration Program, which oversees operations for the Opportunity and Curiosity rovers, as well as NASA’s three Mars orbiters (Mars Odyssey, MRO, and MAVEN) and the Insight lander (which will land on Mars in 109 days). According to NASA, the storm is beginning to end, though it may be weeks or months before the skies are clear enough for Opportunity to exit its hibernation mode.
As noted, dust storms occur on Mars when the southern hemisphere experiences summer, which coincides with the planet being closer to the Sun in its elliptical orbit. Due to increased temperatures, dust particles are lifted higher into the atmosphere, creating more wind. The resulting wind kicks up yet more dust, creating a feedback loop that NASA scientists are still trying to understand.
Since the southern polar region is pointed towards the Sun in the summer, carbon dioxide frozen in the polar cap evaporates. This has the effect of thickening the atmosphere and increasing the surface pressure, which enhances the process by helping suspend dust particles in the air. In some cases, the dust clouds can reach up to 60 km (40 mi) or more in elevation.
Planet-wide dust storms are a relatively rare occurrence on Mars, taking place every three to four Martian years (the equivalent of approximately 6 to 8 Earth years). Such storms have been viewed many times in the past by missions like Mariner 9 (1971), Viking I (1971) and the Mars Global Surveyor (2001). In 2007, a similar storm took place that darkened the skies over where Opportunity was stationed – which led to two weeks of minimal operations and no communications.
While smaller and less intense the storm that took place back in 2007, the current storm intensified to the point where it led to a level of atmospheric opacity that is much worse than the 2007 storm. In effect, the amount of dust in the atmosphere created a state of perpetual night over the rover’s location in Perseverance Valley, which forced the rover’s science team to suspend operations.
This is due to the fact that Opportunity – unlike the Curiosity rover, which runs on nuclear-powered battery – relies on solar panels to keep its batteries charged. But beyond suspending operations, the prolonged dust storm also means that the rover might not be to keep its energy-intensive survival heaters running – which protect its batteries from the extreme cold of Mars’ atmosphere.
Luckily, NASA scientists who have been observing the global event indicated that, as of last Monday (July 23rd), more dust was falling out of the planet’s thin air than was being raised into it. This means that the global weather event has reached its decay phase, where dust-raising events either become confined to smaller areas or stop altogether.
Using its Mars Color Imager (MARCI) and Mars Climate Sounder (MCS), NASA’s Mars Reconnaissance Orbiter (MRO) also noted surface features were beginning to reappear and that temperatures in the middle atmosphere were no longer rising – which indicates less solar heating by dust. The Curiosity rover also noted a decline in dust above its position in the Gale Crater on the other side of the planet.
This is certainly good new for the Opportunity rover, though scientists expect that it will still be a few weeks or months before its solar panels can draw power again and communications can be reestablished. The last time communications took place with the rover was on June 10th, but if there’s one thing the Opportunity rover is known for, it’s endurance!
When the rover first landed on Mars on January 25th, 2004, its mission was only expected to last ninety Martian days (sols), which is the equivalent of about 92.5 Earth days. However, as of the writing of this article, the rover has endured for 14 years and 195 days, effectively exceeding its operational lifespan 55 times over. So if any rover can survive this enduring dust storm, its Opportunity!
In the meantime, multiple NASA missions are actively monitoring the storm in support of Opportunity and to learn more about the mechanics of Martian storms. By learning more about what causes these storms, and how smaller ones can merge to form global events, future robotic missions, crewed missions and (quite possibly) Martian colonists will be better prepared to deal with them.
The weather patterns on Mars are rather fascinating, owing to their particular similarities and differences with those of Earth. For one, the Red Planet experiences dust storms that are not dissimilar to storms that happen regularly here on Earth. Due to the lower atmospheric pressure, these storms are much less powerful than hurricanes on Earth, but can grow so large that they cover half the planet.
Recently, the ESA’s Mars Express orbiter captured images of the towering cloud front of a dust storm located close to Mars’ northern polar region. This storm, which began in April 2018, took place in the region known as Utopia Planitia, close to the ice cap at the Martian North Pole. It is one of several that have been observed on Mars in recent months, one which is the most severe to take place in years.
The images (shown above and below) were created using data acquired by the Mars Express‘ High Resolution Stereo Camera (HRSC). The camera system is operated by the German Aerospace Center (DLR), and managed to capture images of this storm front – which would prove to be the harbinger of the Martian storm season – on April 3rd, 2018, during its 18,039th orbit of Mars.
This storm was one of several small-scale dust storms that have been observered in recent months on Mars. A much larger storm emerged further southwest in the Arabia Terra region, which began in May of 2018 and developed into a planet-wide dust storm within several weeks.
Dust storms occur on Mars when the southern hemisphere experiences summer, which coincides with the planet being closer to the Sun in its elliptical orbit. Due to increased temperatures, dust particles are lifted higher into the atmosphere, creating more wind. The resulting wind kicks up yet more dust, creating a feedback loop that NASA scientists are still trying to understand.
Since the southern polar region is pointed towards the Sun in the summer, carbon dioxide frozen in the polar cap evaporates. This has the effect of thickening the atmosphere and increases surface pressure, which enhances the storms by helping to suspend dust particles in the air. Though they are common and can begin suddenly, Martian dust storms typically stay localized and last only a few weeks.
While local and regional dust storms are frequent, only a few of them develop into global phenomena. These storms only occur every three to four Martian years (the equivalent of approximately 6 to 8 Earth years) and can persist for several months. Such storms have been viewed many times in the past by missions like Mariner 9 (1971), Viking I (1971) and the Mars Global Surveyor (2001).
In 2007, a large storm covered the planet and darkened the skies over where the Opportunity rover was stationed – which led to two weeks of minimal operations and no communications. The most recent storm, which began back in May, has been less intense, but managed to create a state of perpetual night over Opportunity’s location in Perseverance Valley.
As a result, the Opportunity team placed the rover into hibernation mode and shut down communications in June 2018. Meanwhile, NASA’s Curiosity rover continues to explore the surface of Mars, thanks to its radioisotope thermoelectric generator (RTG), which does not rely on solar panels. By autumn, scientists expect the dust storm will weaken significantly, and are confident Opportunity will survive.
Understanding how global storms form and evolve on Mars will be critical for future solar-powered missions. It will also come in handy when crewed missions are conducted to the planet, not to mention space tourism and colonization!
Martian dust storms, which occur during the summer season in the planet’s southern hemisphere, can get pretty intense. Over the course of the past few weeks, a global dust storm has engulfed Mars and forced the Opportunity rover to suspend operations. Given that this storm is much like the one that took place back in 2007, which also raged for weeks, there have been concerns over how this development could affect rover operations.
Meanwhile the Curiosity rover managed to snap pictures of the thickening haze caused by the storm. Though Curiosity is on the other side of the planet from where Opportunity is currently located, atmospheric dust has been gradually increasing over it. But unlike Opportunity, which runs on solar power, Curiosity will remain unaffected by the global storm thanks to its nuclear-powered battery, and is therefore in a good position to study it.
As already noted, Martian storms occur during summer in the southern hemisphere, when sunlight warms dust particles and lifts them higher into the atmosphere, creating more wind. The resulting wind kicks up yet more dust, creating a feedback loop that NASA scientists are still trying to understand. Since the southern polar region is pointed towards the Sun in the summer, carbon dioxide frozen in the polar cap evaporates.
This has the effect of thickening the atmosphere and increasing the surface pressure, which enhances the process by helping suspend dust particles in the air. In some cases, the dust clouds can reach up to 60 km (40 mi) or more in elevation. Though they are common and can begin suddenly, Martian dust storms typically stay contained to a local area and last only about a weeks.
By contrast, the current storm has lasted for several weeks and is currently covering an area that would span North America and Russia combined. While smaller than the storm that took place back in 2007, this storm has intensified to the point where it created a perpetual state of night over the rover’s location in Perseverance Valley and led to a level of atmospheric opacity that is much worse than the 2007 storm.
When dust storms occur, scientists measure them based on their opacity level (tau) to determine how much sunlight they will prevent from reaching the surface. Whereas the 2007 storm had a tau level of about 5.5, this most recent storm reached an estimated tau of 10.8 earlier this month over the Perseverance Valley – where Opportunity is located.
The intensity of the storm also led Bruce Canton, deputy principal investigator of the Mars Color Imager (MARCI) camera onboard NASA’s Mars Reconnaissance Orbiter (MRO), to declare that the storm has officially become a “planet-encircling” (or “global”) dust event. Above the Gale Crater, where Curiosity is located, the tau reading is now above 8.0 – the highest ever recorded by the mission.
While the storm has some worried about the fate of Opportunity, which is Mars’ oldest active rover (having remained in operation for over 14 years), it is also an chance to address one of the greatest questions scientists have about Mars. For example, why do some storms span the entire planet and last for months while others are confined to small areas and and last only a week?
The animation (shown above) consists of a series of daily photos captures by Curiosity’s Mast Camera (Mastcam), which show the sky getting hazier over time. While taking these pictures, Curiosity was facing the crater rim, about 30 km (18.6) away from where it stands inside the crater. This sun-obstructing wall of haze is about six to eight times thicker than normal for this time of season.
Nevertheless, Curiosity’s engineers – which are based at NASA’s Jet Propulsion Laboratory in Pasadena, California – have studied how the growing dust storm could affect the rover’s instruments and concluded that it poses little risk. Ironically enough, the largest impact will be on the rover’s cameras, which require extra exposure time due to the low lighting conditions.
As Jim Watzin, the director of NASA’s Mars Exploration Program at the agency’s headquarters in Washington, explained in a NASA press release earlier this month:
“This is the ideal storm for Mars science. We have a historic number of spacecraft operating at the Red Planet. Each offers a unique look at how dust storms form and behave – knowledge that will be essential for future robotic and human missions.”
However, all dust events, regardless of size, help to shape the Martian surface. As such, studying their physics is critical to understanding the Martian climate, both past and present. As Rich Zurek, the chief scientist for the Mars Program Office at NASA’s Jet Propulsion Laboratory, indicated:
“Each observation of these large storms brings us closer to being able to model these events – and maybe, someday, being able to forecast them. That would be like forecasting El Niño events on Earth, or the severity of upcoming hurricane seasons.”
The ability to understand the causes and dynamics of Martian dust storms would not only lead to a better understand of how weather works on other planets, it would also be of immense importance if and and when humans begin traveling to the Red Planet on a regular basis. For instance, if SpaceX really does intend to bring tourists to Mars in the future, said tourists will want to avoid booking during “storm season”.
And if humans should choose to someday make Mars their home, they will need to know when planet-spanning dust storms are coming, especially since their habitats will likely be relying on wind and solar power. In the meantime, NASA and other space agencies will continue to monitor this storm and the Opportunity rover is expected to come through (fingers crossed!) unscathed!
NASA’s Opportunity mission can rightly be called the rover that just won’t quit. Originally, this robotic rover was only meant to operate on Mars for 90 Martian days (or sols), which works out to a little over 90 Earth days. However, since it made its landing on January 25th, 2004, it has remained in operation for 14 years, 4 months, and 18 days – exceeding its operating plan by a factor of 50!
However, a few weeks ago, NASA received disturbing news that potentially posed a threat to the “little rover that could”. A Martian storm, which has since grown to occupy an area larger than North America – 18 million km² (7 million mi²) – was blowing in over rover’s position in the Perseverance Valley. Luckily, NASA has since made contact with the rover, which is encouraging sign.
NASA’s Mars Reconnaissance Orbiter first detected the storm on Friday, June 1st, and immediately notified the Opportunity team to begin preparing contingency plans. The storm quickly grew over the next few days and resulted in dust clouds that raised the atmosphere’s opacity, which blocked out most of the sunlight from reaching the surface. This is bad news for the rover since it relies on solar panels for power and to recharge its batteries.
By Wednesday, June 6th, Opportunity’s power levels had dropped significantly and the rover was required to shift to minimal operations. But beyond merely limiting the rover’s operations, a prolonged dust storm also means that the rover might not be able to keep its energy-intensive survival heaters running – which protect its batteries from the extreme cold of Mars’ atmosphere.
The Martian cold is believed to be what resulted in the loss of the Spirit rover in 2010, Opportunity’s counterpart in the Mars Exploration Rover mission. Much like Opportunity, Spirit‘s mission as only meant to last for 90 days, but the rover managed to remain in operation for 2269 days (2208 sols) from start to finish. It’s also important to note that Opportunity has dealt with long-term storms before and emerged unscathed.
Back in 2007, a much larger storm covered the planet, which led to two weeks of minimal operations and no communications. However, the current storm has intensified as of Sunday morning (June 10th), creating a perpetual state of night over the rover’s location in Perseverance Valley and leading to a level of atmospheric opacity that is much worse than the 2007 storm.
Whereas the previous storm had an opacity level (tau) of about 5.5, this new storm has an estimated tau of 10.8. Luckily, NASA engineers received a transmission from the rover on Sunday, which was a positive indication since it proved that the rover still has enough battery charge to communicate with controllers at NASA’s Jet Propulsion Laboratory. This latest transmission also showed that the rover’s temperature had reached about -29 °C (-20 °F).
Full dust storms like this and the one that took place in 2007 are rare, but not surprising. They occur during summer in the southern hemisphere, when sunlight warms dust particles and lifts them higher into the atmosphere, creating more wind. That wind kicks up yet more dust, creating a feedback loop that NASA scientists are still trying to understand. While they can begin suddenly, they tend to last on the order of weeks or even months.
A saving grace about these storms is that they limit the extreme temperature swings, and the dust they kick up can also absorb solar radiation, thus raising ambient temperatures around Opportunity. In the coming weeks, engineers at the JPL will continue to monitor the rover’s power levels and ensure that it maintains the proper balance to keep its batteries in working order.
In the meantime, Opportunity’s science operations remain suspended and the Opportunity team has requested additional communications coverage from NASA’s Deep Space Network – the global system of antennas that communicates with all of the agency’s deep space missions. And if there’s one thing Opportunity has proven, it is that it’s capable of enduring!
Fingers crossed the storm subsides as soon as possible and the little rover that could once again emerges unscathed. At this rate, it could have many more years of life left in it!