Phobos and Deimos

Mars has two small moons. Phobos, which is about 11.5 km across, was imaged on 26 March, 2019, as in moved across the face of the Sun from Curiosity rover’s post of view. Deimos, which is only about 2.3 km across, was 17 March. Phobos doesn’t completely cover the Sun, so Curiosity saw what could be considered an annular eclipse. Deimos is so small compared to the disk of the Sun, astronomers would say it transited the Sun.

Image Credits: NASA

Bonus GIF—This series of images shows the shadow of Phobos as it sweeps over Curiosity and darkens the sunlight near sunset on 25 March.

Petrified Dunes on Mars

mcam-sol1087_with-scalebarThe crossbedding in the sandstone of this ridge on a lower slope of Mars’ Mount Sharp is typical of windblown sand dunes that have petrified. The Curiosity rover used its Mastcam to capture this panorama on 27 August, 2015. Similar sandstone is common in the American Southwest. Click the image to embiggen it.

Image Credit—NASA

Sunset on Mars

Mars_sunsetThe Curiosity rover recorded this sequence of views of the Sun setting at the close of the mission’s 956th Martian day, or sol (15 April, 2015), from the rover’s location in Gale Crater. This was the first sunset photographed in color by Curiosity.

The four images in the sequence were taken over a period of 6 minutes and 51 seconds.

Image Credit: NASA



main_ceres_annotated_curiousityThe Curiosity rover on Mars has taken the first image of asteroids taken from the surface of Mars. The image includes two asteroids, the dwarf planet Ceres and Vesta. This version includes Mars’ moon Deimos in a circular, exposure-adjusted inset and square insets at left from other observations the same night. Click the image to embiggen it. Ceres is very dim, but easier to spot in the larger version.

Image Credit: NASA

An Annular Eclipse

phobos_eclipseThese three images are of Phobos, Mars’s larger moon, passing directly in front of the sun. They were taken about three seconds apart by the Curiosity rover. Curiosity photographed this eclipse with the telephoto-lens camera of the rover’s Mast Camera pair on 17 August, 2013, the 369th Martian day (or sol) of its mission on Mars. Because this eclipse occurred near mid-day at Curiosity‘s location on Mars, Phobos was nearly overhead, closer to the rover than it would have been earlier in the morning or later in the afternoon. This timing made Phobos’ silhouette relatively large against the sun—as close to a total eclipse of the sun as is possible from Mars.

Image Credit: NASA

The Moons of Mars


moons_apparent-sizesThe Curiosity rover on Mars used its cameras to take the series of pictures stitched together to make this video. These are the first images from missions on the surface which have caught one moon eclipsing the other. The images were taken on 1 August, but some of the full-resolution frames were not downlinked until more than a week later, in the data-transmission queue behind higher-priority images being used for planning the rover’s drives.

The picture on the left shows how big the moons of Mars appear to be, as seen from the surface of Mars, compared to the size that Earth’s moon seen from the surface of Earth.

Image and Video Credits: NASA

Curiosity From Space

curiosityfromspaceThe Mars rover Curiosity appears as a bluish dot at the right end of a thin, wiggly line of tracks in this enhanced-color view from the High Resolution Imaging Science Experiment (HiRISE) camera on the Mars Reconnaissance Orbiter. The camera took this picture on 27 June, 2013.

The two scour marks at the Bradbury Landing site where the Mars Science Laboratory mission’s skycrane landing system landed Curiosity on 6 August, 2012, are on the far left. Dark scour marks show where the landing system’s rockets swept away reddish surface dust. Visible tracks lead from the landing site toward the rover.

Image Credit: NASA

Meanwhile, On Mars

right-navcam-sol329The Curiosity rover is still at work. The lower slopes of Mount Sharp appear at the top of this image taken by the rover’s right Navigation Camera at the end of a drive of about 41 meters during the 329th Martian day (or sol) of the mission Mars (9 July, 2013). That was the third drive by Curiosity since finishing work at the mission’s final science target in the “Glenelg” area east of the rover’s landing site. The rover’s next major destination on the lower slopes of Mount Sharp lies about 8 km to the southwest. That’s the turret of tools at the end of Curiosity’s robotic arm in the picture’s foreground.

Image Credit: NASA

Rock Nest

RockNestThis is Mars, and this is a site picked for the likelihood of its holding clues to the habitability of Mars to ancient life. It’s called “Rock Nest,” and the Curiosity rover has been taking detailed survey pictures. Over 900 of these images have been combined into one of the highest resolution images ever created of the red planet; this panorama containing over a billion pixels in its full-size version (Click the image to embiggen it.) Mt. Sharp, the central peak of the large crater where Curiosity landed and is currently exploring, is near the center of the image. According to the mission plan, Curiosity is scheduled to roll toward Mt. Sharp looking for distinguishing geological and chemical markers along the way.

NASA has posted an interactive and zoomable version of this image here.

There’s been no word of any sighting of a Rock Nest monster.

Image Credit: NASA

Transit of Phobos

phobos_transitMars has a couple of tiny moons named Phobos and Deimos. From the point of view of the Curiosity rover near Mars’ equator, the moons occasionally pass in front of, or “transit,” the Sun. These transits are as near as a Martian observer comes to seeing a partial eclipse of the Sun because the outlines of the moons do not completely cover the Sun. Earth’s Moon, of course, does blocks the entire Sun during a total solar eclipse. These eclipses, like those on Earth, occur in predictable “seasons” a few times each Mars year.

As part of a multi-mission campaign, the Curiosity rover is observing these transits, the first of which involved the moon Phobos grazing the Sun’s disk. The event was observed on Martian day, or sol, 37 (13 September, 2012) using Curiosity‘s Mast Camera, or Mastcam, equipped with special filters for directly observing the sun. This animation shows the transit as viewed by the Mastcam 100-mm camera (M-100).

Mission scientists use these events to very accurately determine the orbital parameters of the Martian moons. Phobos’ orbit is very close to Mars, and it is slowly spiraling in because of tidal forces. These forces change the orbital position of Phobos over time, and accurate measurements of those changes can provide information about the internal structure of that moon and how it dissipates energy. Deimos orbits much farther away and is slowly spiraling out.

NASA’s Mars Exploration Rover Opportunity will also attempt to observe a different set of Phobos and Deimos transits, seen from the other side of the planet, in Meridiani Planum.

Image Credit: NASA

Aeolis Mons

Mars_panoramaThis layered mound, also called Aeolis Mons (aka Mount Sharp), in the center of Gale Crater rises more than 3 miles (5 km) above the crater floor location of NASA’s Curiosity rover. That’s higher than any mountain in the lower 48 states. Lower slopes of Mount Sharp are a destination for the mission, though the rover will first spend many more weeks around a location called “Yellowknife Bay,” where it has found evidence of a past environment favorable for microbial life.

This mosaic was assembled from dozens of telephoto images taken by the 100 mm focal length telephoto lens camera mounted on the right side of Curiosity‘s remote sensing mast during the 45th sol (Martian day) of the rover’s mission on Mars (20 September, 2012, here on Earth).

Image Credit: NASA

One Giant Schlep for Mankind

This picture  shows where the Curiosity rover scooped up some Martian soil. The first scoop sample was taken from a patch of dust and sand called “Rockrest” on 7 October, 2012, which was the 61st sol  (Martian day) of operations. This picture was taken by Curiosity‘s Mast Camera. The color has been enhanced to show the Martian soil as it would appear under lighting conditions on Earth. That allows the Science Team for the mission to more easily analyze the terrain.

During the two-year prime mission of the Mars Science Laboratory Project, researchers are using Curiosity‘s 10 instruments to investigate whether areas in Gale Crater ever offered environmental conditions favorable for microbial life. If the rover survives as well as its two predecessors, there will be plenty more work left. A whole planet full.

Image Credit: NASA


Tire Tracks on Mars

These are tracks left by the Curiosity rover as it completed its first test drive on Mars on 22 August. The rover went forward about 4.5 m, rotated 120 degrees, and then backed up about 2.5 m. The rover is now roughly 6 m  from its landing site.

BTW, the landing site has been named Bradbury Landing after the late author of The Martian Chronicles.

This image was taken by one of Curiosity’s Hazard-Avoidance cameras. The camera has a fish-eye lens.

Image Credit: NASA

Curiosity As Seen From Orbit

The Mars Reconnaissance Orbiter’s HIRES camera has snapped this picture of the Curiosity rover. The image has been color enhanced so that features near the rover stand out. The descent stage blast pattern around the rover shows up as the bluish area (true colors would be more gray). The rover is the dot inside the blue smudge.

Image Credit: NASA

Curiosity Drops Its Heat Shield

This picture was made by the Curiosity rover during its descent to the surface of Mars on 6 August. The image was taken by the Mars Descent Imager instrument known as MARDI and shows the 4.5-meter diameter heat shield when it was about 16 meters from the spacecraft about two and one-half minutes before touch down on Mars and roughly three seconds after heat shield separation. The resolution of all of the MARDI frames was reduced by a factor of eight in order for them to be rapidly transmitted to Earth during the early phase of the mission. Full resolution (1,600 by 1,200 pixel) images will be returned to Earth over the next few months. This picture appears pinched at the edges because it has been geometrically corrected to look flat.

Image Credit: NASA