Marking its 15th anniversary from the start, one of the oldest ships on the Red Planet has provided a view of dust devils, avalanches and more.
Since leaving Earth 15 years ago, NASA‘s March Orbiter Reconstruction has reshaped our understanding of the Red Planet. Veteran space studies temperatures in the thin atmosphere of Mars, underground radar counterparts, and discovers minerals on the planet’s surface. But perhaps what has become most popular are the stunning images.
Among its instruments, the MRO has three cameras: The Mars Color Imager (MARCI) has a fisheye lens that produces a daily global view. The Context Camera (CTX) offers black and white terrain shots 19 kilometers (30-kilometers) wide. These images, in turn, provide context for the highly focused images provided by the MRO’s third camera, the High-Resolution Imaging Science Experiment (HiRISE), which produces the most astonishing images.
Able to magnify surface features at the highest resolution, detailed color images from HiRISE have captured dramatic nature scenes: falling avalanches, dusty skyscrapers, and other features of a changing landscape. The camera has also provided images of other NASA spacecraft on Mars, such as Curiosity and Opportunity rovers. The MRO has even surpassed itself to show HiRISE on Earth and Phobos, one of the two moons of Mars.
As of early August, HiRISE alone had taken 6,882,204 images, generating 194 terabytes of data sent from Mars since 2006. The images below are just a glimpse of the amazing work done by all three cameras in the MRO , which is managed by NASA’s Jet Propulsion Laboratory in Southern California.
Welcome to Mars
Dust storms are routine on Mars. Most are confined to small regions and are not as dramatic as those portrayed in the movies. But once or twice a decade, a series of regional storms will create a domino effect, removing enough dust for the winds to cover the surface in what is called a “dust event surrounding the planet.” This one, captured by MARCI in the summer of 2018, obscured the region above the Opportunity rover, depriving its solar panels of sunlight and eventually leading to the end of the mission.
A Marsian Sky Scrater
As HiRISE climbs over large areas of the surface of Mars, it occasionally discovers surprises like this magnificent dust devil, which was caught from 185 miles (297 kilometers) above the earth. The shadow length of this vortex indicates that it was more than half a mile (800 meters) high – about the size of the Burj Khalifa of the United Arab Emirates, the tallest building on Earth.
HiRISE has caught avalanches in action. As seasonal ice evaporated in the spring, these 1,640-foot-long (500-foot-long) rocks at the north pole of Mars began to crumble. Such rocks reveal the deepest scales of time on the planets, exposing the numerous layers of ice and dust that have settled over different eras. Like the rings of a tree, each layer has a story to tell scientists how the environment was changing.
This will leave a stomach
Mars has a thin atmosphere – only 1% as dense as that of Earth. As a result, there is less protective barrier to burning space debris. This means that larger meteors make it through the atmosphere of the Red Planet than Earth. CTX has discovered over 800 new impact craters during the MRO mission. After CTX noticed this, the scientists got a more detailed image with HiRISE.
The crater is approximately 100 meters (30 meters) in diameter and is surrounded by a large radius eruption area. In examining the distribution of ejecta – debris thrown out during the formation of a crater – scientists can learn more about the impact event. The eruption that created this crater threw the object up to 9.3 miles (15 kilometers).
The face of time
The Earth changes over time, so having a spaceship on Mars for years offers a unique perspective. “The more we look, the more we discover,” said Leslie Tamppari, deputy MOC project scientist at JPL. “Before the MRO, it was not clear what really changed on Mars, if anything. We thought the atmosphere was so thin that there was almost no sand movement and the most dune movement occurred in the ancient past.
We now know that this is not the case. “False color” has been added to this image to highlight certain details, such as the tops of dunes and shrubs. Many of these terrestrial forms are migrating, as they do on Earth: Sand grains from sand wheat, they have been carried by the wind, crawling across the planets for millions of years.
Return to Atcha, Earth
The MRO has not just looked at Mars. This component, made up of four sets of HiRISE images of our Earth and Moon, was actually the second time HiRISE had captured our home planet.
Named the Greek god of fear, Phobos is one of the two moons of Mars (Deimos, called the god of terror, is the other), and is only about 13 miles (21 kilometers) beyond. The Stickney Crater, landing on the lower right of the Moon, is about 5.6 miles (9 kilometers) wide in this HiRISE image. Despite its small size, Phobos is of great interest to scientists: Is it a captured asteroid, or a piece of Mars that exploded after a massive impact? A Japanese mission is scheduled to land on Phobos in the near future, and the Moon has been proposed as a staging site for astronauts before they go to Mars.
Based on an image from CTX, this map shows the full traversal of the Opportunity rover after exploring the planet for more than 15 years. Both HiRISE and CTX are used by scientists to map landing sites for future human and robotic missions, as well as to record the progress of rovers on Earth.
HiRISE has often been used to transcend images of NASA spacecraft to the Martian surface, capturing Spirit, Opportunity and Curiosity, as well as the immobile lands of Phoenix and InSight. NASA’s newest rover, Perseverance, is currently heading to Jezero Crater. Once it arrives on February 18, 2021, you can decide that there will be some images as well.
The eyes have it
It takes sharp eyes to find unique features on Mars, like repetitive slope lines. These dark stripes appear in the same places at the same time of year. It was originally proposed that they were caused by brine, as salt could allow water to remain liquid in the thin Martian atmosphere. The consensus now, however, is that they are actually caused by dark sand slipping into the ranges.
The landslides were discovered by Lujendra Ojha, who was an undergraduate student at the University of Arizona who operates the HiRISE camera, and is now a professor at Rutgers University. “Sometimes you’re just looking at the right place at the right time,” Ojha said. “I was completely confused when I noticed this because I was just a student at the time – I was not even on a planetary program.” Students work alongside experienced scientists to see unique features like these in HiRISE images.