Bigger view. | Sand dunes and ripples in Proctor Crater on Mars, as seen by the Mars Reconnaissance Orbiter on February 9, 2009. Image via NASA / JPL-Caltech / Univ. of Arizona.
Mars is a dry desert world, covered with reddish sand. In our life periods, spaceships have revealed its amazing landscape and sweeping landscapes. It is a world that thinks of Earth at the same time, yet strange and strange. This week, to mark the launch of the Mars Reconnaissance Orbiter 15 years ago, NASA shared some of the orbiter’s most breathtaking images. We found these images very nice and think you will too, whether you are a Mars aficionado or a newbie.
The Mars Reconnaissance Orbiter (MRO) has three cameras: The Mars Color Imager (MARCI), which has a fisheye lens for a daily global view of the planet; the Context Camera (CTX), which provides 19-mile-wide (30-kilometer-wide) black-and-white terrain photos; and the High-Resolution Imaging Science Experiment (HiRISE), which produces the stunning and jaw-dropping images that have made MRO famous. HiRISE takes the highest resolution orbital images of the Martian surface ever obtained, and in full color. She shows sand dunes, avalanches, craters, dust devils, ancient river and lake beds, mountains, spheres and more in beautiful detail. MRO has even been able to photograph robbers like Curiosity and Opportunity, on the planet far below. It also photographed the two small Martian moons, Phobos and Deimos.
The image on top of the sand dune and wrinkles in Proctor Crater is in enhanced color to bring out details. Like other images of still-active sand dunes, it shows that Mars is not a completely inactive, motionless world. Leslie Tamppari, MRO deputy project scientist at JPL, said in a statement:
The more we see, the more we discover. Before MRO, it was not clear what on Mars really changed, if anything. We thought the atmosphere was so thin that there was almost no sand movement and most of the thin movement happened in the ancient past.
Bigger view. | Recurring slope line (RSL) in a crater in Valles Marineris. Image via NASA / JPL-Caltech / Univ. of Arizona.
In the image above, we see dark stripes, called recurring slope lines (RSL), on a steep crater wall in Valles Marineris. There is still a lot of debate about whether that might be small streams of salty liquid water.
MRO has also observed dust storms on Mars, as seen in the image below. Most storms are relatively small and regional, but others can grow to cover the entire planet, about once or twice in decades. These are referred to as “planet-encringing dust events.” MARCI took the images in the summer of 2018. This was the storm that clouded the skies over the Opportunity rover and caused it to run out of power from its solar panels.
In the May view we see the chasms of Valles Marineris (left), Meridiani Planum (center), an autumn dust storm in Acidalia Planitia (above) and the early spring south polar cap (below). The same regions are in the July view, but completely hidden by dust.
Bigger view. | Global dust storm seen by MRO in summer 2018 (right). Image via NASA / JPL-Caltech / MSSS.
Dust storms are not the only dusty phenomenon MRO has seen. The following image below is a good example of a snake-like dust devil, captured on February 16, 2012. The image was taken in a late spring afternoon in the Amazonis Planitia region of northern Mars.
The plume is about 98 feet (30 meters) in diameter, and based on the length of the shade, is more than half a kilometer (800 meters) high!
A westerly breeze made the S-like arc in the plume. Just like on Earth, Martian winds get their energy from the sun, even though Mars is much farther from the sun than Earth. Even though the winds are less this time of year, they are still strong enough to produce dust devils like these.
Dust devils are also seen close to the ground by the robbers Opportunity, Spirit and Curiosity.
Bigger view. | A spinning dust devil in the Amazonis Planitia region of northern Mars. Image via NASA / JPL-Caltech / Univ. of Arizona.
Dust storms and dust devils are not the only way Mars is still active. Avalanches are quite another occurrence, especially when seasonal ice evaporates in the warmer spring.
In the image below, taken on May 29, 2019, MRO conquered avalanches on 1,640-foot (500-meter-high) cliffs at the North Pole of Mars. The avalanches also had the effect of exposing hidden layers of ice and dust in the cliffs, millions of years or more back. For scientists, these layers are like reading the history of Mars, and give clues as to how the environment changed over time in the region.
Bigger view. | Avalanches on steep cliffs at the Martian North Pole on May 29, 2019. Image via NASA / JPL-Caltech / Univ. of Arizona.
Another thing that MRO is good at is finding new craters. Such “fresh” craters can be identified by the new-looking ejecta blanket of rocky debris around them. Many more of these can be seen on Mars because of the planet’s very thin atmosphere, which does not burn larger meteors as easily as the Earth’s atmosphere. More of them therefore have an impact on the planet.
MRO has so far found more than 800 new impact craters during its mission. The one pictured below is about 98 meters (30 meters) across. The impact was strong enough to throw ejecta up to 15 km.
On Mars, craters also last much longer than they do on Earth, again because of the thin atmosphere that erodes them more slowly.
Bigger view. | A new impact crater, detected by MRO on November 19, 2013. Image via NASA / JPL-Caltech / Univ. of Arizona.
MRO has been orbiting Mars since 2006, producing no less than 6,882,204 images and generating 194 terabytes of data. Those perceptions of the red planet have helped to revolutionize our knowledge of this familiar yet alien world.
MRO has also taken images of mud volcanoes, and a recent study showed that mud flowing from them flows in a manner similar to lava on Earth.
Like taking unbelievable images, MRO also studies Mars with several other instruments. It measures the temperature of the atmosphere and dust and water vapor with Mars Climate Sounder (MCS), peers below the surface with radar with Shallow Radar (SHARAD) and analyzes various minerals on the surface in rocks and sand with the Compact Reconnaissance Imaging Spectrometer for Mars (CRISM).
Bigger view. | NASA’s Curiosity rover in Gale Crater, as seen by MRO out of orbit. Image via NASA / JPL-Caltech / Univ. of Arizona.
Bigger view. | The largest moon Phobos of Mars, as seen by MRO on March 23, 2008. Image via NASA / JPL-Caltech / Univ. of Arizona.
Bigger view. | Conical hills are thought to be mud volcanoes, in Coprates Chasma on Mars, photographed by MRO. Image by Petr Brož / MRO / NASA / JPL / University of Arizona / The conversation.
Bigger view. | Image with enhanced colors of MRO of the future landing site of the Perseverance rover in Jezero Crater in February 2021. An old river delta is still clearly visible. Image via NASA / JPL-Caltech / ASU.
The images returned by MRO were some of the most incredible of any planetary mission, and are the perfect way to celebrate the 15th anniversary of the launch. Together with all the other data so far, they have forever changed our view and understanding of the red planet.
More information about MRO is available on the mission website. Check out the HiRISE website for many thousands more images! You can even make a request for the spaceship to take pictures of specific targets.
Bottom line: NASA has posted great photos of Mars to celebrate the 15th anniversary of the launch of Mars Reconnaissance Orbiter.
Via Jet Propulsion Laboratory
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