Towering dust devils and avalanches: 12 stunning images from NASA's Mars orbiter
- NASA's Mars Reconnaissance Orbiter has taken nearly 7 million pictures of the red planet since leaving Earth 15 years ago.
- From dust storms to avalanches, the images reveal details of Mars' surface and weather patterns.
- Here are 12 of the most beautiful visuals the orbiter has captured so far.
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NASA's Mars Reconnaissance Orbiter left Earth on August 12, 2005 — almost exactly 15 years ago. The satellite began circling the red planet on March 10, 2006, and since then it has studied Martian temperatures, detected minerals on the planet's surface, and taken nearly 7 million images of our closest planetary neighbor.
The orbiter's main goal is to help scientists understand the role water has played on Mars throughout the planet's history, and the degree to which water still exists on the planet as liquid, vapor, or ice.
In honour of the orbiter's 15th anniversary, here are some highlights from its massive portfolio of photos, and what each image reveals about Mars.
The dust devil in this photo snakes 185 miles above Mars' surface. Such dust devils hurl heat-trapping dust into the air, which impacts the planet's weather patterns.
Most dust storms on Mars occur on isolated sections of the planet. But every 10 years or so, regional storms combine into a huge one that covers the entire surface.
The animated graphic above shows the planet in May 2018, before the dust storm began, then in June, when it hit full force.
This illustrated image shows the entire 28-mile path of Opportunity, from its landing site in the Eagle Crater to Perseverance Valley, the site of its final transmission.
This animated image shows the rover before and after it made a journey of 1,106 feet across Mount Sharp, a mountain within the Gale Crater.
This photo, taken by the orbiter's High Resolution Imaging Science Experiment (HiRISE) camera, captures huge, cresting waves of sand called megaripples, along with a large dune.
In the Martian spring, warmer air vaporises ice chunks in Mars' North Pole, causing these giant avalanches.
Stretches of brain terrain can be found throughout mid-latitude regions of Mars. Some scientists think that these land areas sit on top of an icy core, so when chunks of underground ice vaporise, they cause sections of land above them to collapse.
Some scientists think salty sand grains might pull water vapor from the atmosphere as it warms, causing those grains to darken and tumble downward. The phenomenon is known as recurrent slope lineae.
These large mounds contain craters at their center that resemble the collapsed centers of volcanoes on Earth. The pitted mounds may contain methane — a topic of interest for researchers, since it's not yet known whether Mars' methane comes from geologic events, microbial life, or both.
The crater in this photo is roughly 100 feet wide, with a much larger blast zone around it.
Scientists still don't know whether Phobos is an asteroid that entered the red planet's orbit or a chunk of Mars that broke off and became a moon millions of years ago.
Mars's other moon, Deimos, is even tinier than Phobos: It's only 9 miles across.
This composite photo was taken when Mars was about 127 million miles from Earth. Photo processors brightened the moon so to be visible next to our much brighter home planet.