Category Archives: Mars
The HiRISE camera aboard NASA’s Mars Reconnaissance Orbiter (MRO) is specifically designed to take super high-resolution images of the surface of Mars but it also does a pretty darn good job capturing pictures of other objects too—like Jupiter and its Galilean moons, several hundred million miles away! The image above was captured in expanded color (that is, it includes wavelengths in infrared) by HiRISE on January 11, 2007, and shows the giant planet from Mars orbit.
Mars and Jupiter were at opposition at the time, only about 345 million miles apart.
Here’s a view of our home planet and its lovely Moon captured from 127 million miles away by NASA’s Mars Reconnaissance Orbiter on November 20, 2016. The sunlit part of Earth shows eastern Asia, the Indian Ocean, and Australia with ice-covered Antarctica visible as a bright white spot. The Moon has been brightened in this image, since it would be too dark in relation to a properly-exposed Earth to be readily visible (and I added more dark background to frame them a bit better.) But the positions and sizes of the two worlds are as captured by the HiRISE instrument, which was designed to map the surface of Mars in exquisite detail but occasionally is aimed to take a look back homeward.
NASA’s Curiosity rover may be getting all the attention on Mars these days but the real overachiever is Opportunity — it’s been busy exploring, studying, and traveling across the planet’s surface for over 12 years now and still going strong!
Launched July 7, 2003, the rover is currently in its 4,270th sol — 4,180 past “warranty.” (Pretty impressive for a mission that was only planned to last 90 days!)
Here’s a view of a section of a crater on Mars filled with a lacework of bright spidery fractures, acquired on Sept. 20, 2015 with the HiRISE camera aboard NASA’s Mars Reconnaissance Orbiter. The crater is approximately 3 miles (5 km) wide and located in Mars’ north polar region, and its old, infilled interior has undergone countless millennia of freeze/thaw cycles that have broken the surface into polygons of all sizes, outlined by frost-filled cracks.
The fractured segments get increasingly more compressed closer to the crater rim, which contains the outward freeze expansion.
According to the image description from the HiRISE team:
The crater rim constrains the polygon formation within the crater close to the rim, creating a spoke and ring pattern of cracks. This leads to more rectangular polygons than those near the center of the crater. The polygons close to the center of the crater display a more typical pattern. A closer look shows some of these central polygons, which have smaller polygons within them, and smaller polygons within those smaller polygons, which makes for a natural fractal!
Source: HiRISE/University of Arizona
Phobos, the largest — yet at just 16 miles wide still quite tiny — moon of Mars is getting ripped apart by the gravitational pull of its parent planet… and it bears the scars to show it, scientists have determined.
Long parallel grooves that wrap around the surface of Phobos are thought to be stress fractures — surface evidence of the tidal forces that will one day cause the moon to break apart entirely. This fate is not surprising to scientists, but that we’re seeing it in action is fascinating.
“We think that Phobos has already started to fail, and the first sign of this failure is the production of these grooves,” said Terry Hurford of NASA’s Goddard Space Flight Center in Greenbelt, Maryland.