Embedded on board the probe Mars Reconnaissance OrbiterMars Reconnaissance Orbiterthe HiRISE camera has been producing a multitude of photographsphotographs surface of Mars, each more impressive than the next. If these images are available to the general public, they are mainly intended for scientists who study the history of the planet but also the atmospheric and geological processes that currently govern its surface.
The Colors of Mars… Seen Through the Eyes of HiRISE
Futura offers you here a top 10 of the most beautiful Martian landscapes captured by HiRISE. While some are in black and white, others are colorized. Be careful, however, not to consider that these are “real” colorscolors Of March. HiRISE does not see the world as we do. The camera produces its shots using several filters, each of which only allows a certain color spectrum to pass through. HiRISE thus has “red” filters, which filter the wavelengthswavelengths of the lightlight between 570 and 830 nanometersnanometers“blue-green” filters which only allow wavelengths below 580 nm to pass, and “infra-red” filters for wavelengths above 790 nm.
Why use these filters? Quite simply because they make it possible to better identify the differences between materials and texturestextures Martian soil. An essential consideration to determine the nature of the different geological formations visible. The poorly consolidated grains of the dunes will in fact not reflect the light in the same way as the indurated rocks of the basement and this difference, imperceptible to our eyeeye, will be visible thanks to the filters. The images thus obtained are further processed by computer to obtain a contrastcontrast maximum color that allows clear identification of geological formations.
Anyway, these colorful images only bring a touch of exoticism to this fascinating world!
A rugged terrain
With these two images, we understand better why the advance of rovers on the surface of Mars is sometimes difficult! Far from being a vast flat expanse, the Martian landscape has been shaped over billions of years by windswinds which gradually nibble the rocks of the crust and transport the grains of sandsand so created. The surface of Mars is therefore a privileged terrain for studying the formation and evolution of dunes over time.
At the poles of Mars, it is not the wind, but the ice, which shapes the landscape. Mars indeed has polar capspolar caps permanent, like the Earth, even if their thickness and composition are very different. Indeed, they are composed of water ice but also of dry ice, whose sublimationsublimation under the effect of seasonal warming sometimes draws strange patterns.
Dunes shaped by the wind
Among the geological formations of the Martian surface, the dunes are certainly the most aesthetic. Scientifically, they communicate a lot of information about the strength and direction of the winds that sweep the surface of the planet.
These craters that teach us more about the history of Mars
If the images taken by HiRISE mainly provide information on the surface of Mars, they sometimes provide insight into deeper areas. The craters, by impacting the crustcrustcan indeed reveal the structure and composition of deeper levels.
The study of craters is also very important to understand the presence of liquid water in the past of Mars. Indeed, many of these depressions are believed to have harbored lakes several billion years ago.
Mars, a dead planet?
Aside from the action of the wind and the annual freeze-thaw cycles, the surface of Mars appears rather calm and still. In comparison, the earth’s surface is very agitated, in particular because of the intense tectonic activity that shapes it. If Mars therefore seems “tectonically” dead, certain structures nevertheless question scientists. This is the case of this circular depression. The radial fractures that compose it clearly indicate a collapsecollapse whose origin is for the moment mysterious…
Waiting for the arrival of the rover on site PerseverancePerseverancethe NasaNasa today treats us to some of the most beautiful images taken by its Mars Reconnaissance Orbiter (MRO) mission. A mission launched 15 years ago, almost to the day.
Article of Nathalie MayerNathalie Mayer published on August 16, 2020
Map the surface of Mars. This is the first mission assigned 15 years ago to the NASA MRO (Mars Reconnaissance Orbiter) probe. Since its launch on August 12, 2005 — and especially since its implementation orbitorbitin March 2006 — it sent stunning images back to Earth, which literally reshaped the way astronomersastronomers envisioned the Red Planet.
All thanks to its three cameras:
- Mark (Mars Color Imager) and its purpose fisheye which produces a daily global view of the red planet;
- CTX, the context camera that provides black and white images 30 km wide;
- and of course, the HiRISE camera — for High Resolution Imaging Science Experiment — which over the years has provided the public with incredible images of the mysterious Red Planet.
To mark 15 years since the launch of the MRO mission, NASA is today releasing some of these most striking photos. Find the many images captured by the camera at high resolutionresolution HiRise of the MRO probe on the dedicated site uahirse.org and HiRise English as well as on the Flickr page of the instrument.
Dust storm on Mars
On Mars, dust storms are common. Once or twice a decade, a series of storms kick up enough dust to virtually obscure the entire Martian surface. That of summer 2018 hastened the end of the rover’s mission OpportunityOpportunity. Its solar panels were then deprived of light.
Curiosity seen from space
As early as 2007, HiRISE was strafing the surface of Mars in search of a landing site for the rover CuriosityCuriosity. Later, it is the rover that the camera caught several times, wandering on the Red Planet.
Remember that the incredible resolution of HiRISE allows it to capture spectacular scenes such as avalanchesavalanches or even whirlwindswhirlwinds of dust the size of a building. Or even other Martian missions. In total, nearly seven million images.
And soon, no doubt, Mars Reconnaissance Orbiter will offer us images of Perseverance, NASA’s rover which will arrive on Mars in February 2021.
HiRISE is not the only one to have followed the martian roversmartian rovers from NASA. CTX did the same with Opportunity. Or at least, by photographing the region in which the rover operated, from its landing on the side of theEagle Crater in January 2004, until the end of its mission, on the edge of the crater EndeavorEndeavorin the Persevrance Valley in June 2018.
There is no doubt that the instruments of Mars Reconnaissance Observer will be used to establish maps of future landing sites for robotic missions… or human ones.
On Mars, impressive dust devils
In 15 years, HiRISE has more than once surprised sensational phenomena. Like dust devils, some of which can reach 30 meters in diameter and 800 meters high. This is roughly the height of the tallest skyscraper in the world, the Burj Khalifa, built in Dubai. All this while the exposure to SunSun decreases on Mars at the end of spring and that, as on Earth, the winds, fed by the heatheat solar, should also subside.
Spiders on Mars?
Among the significant discoveries made by MRO, there is that of “spidersspiders ” who emergingemerging of the landscape each spring, on the south pole side of Mars. When the ice cream carbon dioxidecarbon dioxide heats up below the surface, it releases gas below pressurepressure which shatters the dust into small radiating mounds. A phenomenon that does not occur anywhere on Earth.
On the side of the north pole of Mars, rise cliffs some 500 meters high. Layers that were deposited at different times, revealing part of the history of the red planet.
And in the spring, when the seasonal ice — blocks of dry icedry ice laden with dust — vaporize, these cliffs crumble, triggering spectacular avalanches.
A fresh impact crater
L’atmosphereatmosphereof Mars is tenuous. It therefore only very little protects the red planet from the falls of meteoritesmeteorites . During its 15-year mission, Mars Reconnaissance Orbiter has pointed out more than 800 new impact craters there.
Studying these craters and their ejecta allows researchers to learn a bit more about what caused them.
The surface of Mars changes over time
The longevity of the Mars Reconnaissance Orbiter mission has allowed astronomers to see how much the Red Planet’s surface changes over time. They thought until then that, given the weak atmosphere that surrounds it, the movementsmovementssands, in particular, had to remain light. They now knew that was far from the case. Many Martian landforms move — like on Earth — crawling across the planet for millions of years.
Water on Mars
This animation shows the regions of Mars likely to hide water ice below the surface. © NASA, JPL-Caltech
On Mars, some regions hide near-surface water ice. Water that could be easily accessible for future astronauts.
Earth in the rearview mirror
Some 205 million kilometers from our Earth, MRO sometimes allows itself to turn away from its primary objective and turn to our planet to take a nostalgic look at it.
Phobos, a moon of Mars
Earth has only one MoonMoon, but Mars has two. Small in size — PhobosPhobos, the largest, measuring only 26 kilometers in diameter — but of great interest to astronomers. They are particularly intrigued by their shape and origin.
The Stickney crater is the main feature of Phobos. It measures nine kilometers in diameter. The troughs and ranges that many seem to be related to this crater are actually not. Rather, they would have been born from debris ejected by impacts on Mars.
Amazing streaks on the surface of Mars
They were discovered by an undergraduate student. Streaks that appear on Mars in the same places and around the same times of the year, during the hottest months. They are said to be caused by dark sand sliding down slopes.