Perspective view of ancient volcanic plains in the northern high latitudes of Mercury revealed by NASA's Messenger spacecraft. Purple colors are low and white is high, spanning a range of about 2.3 km. Width of area spans about 1200 km. Each line is 5 degrees in latitude and longitude.
Ancient volcanic plains in the northern high latitudes of Mercury revealed by NASA's Messenger spacecraft. Purple colors are low and white is high, spanning a range of about 1 km. Width of area spans about 250 km.
This elevation map of the Beethoven basin is color-coded to show the height of features on Mercury's surface. Mercury lacks a "sea level", so the zero-point reference elevation is defined to be the mean planetary radius of 2440 km. Blue areas, such as within Bello crater on the floor of Beethoven, have negative elevations. The red and white areas to the southwest are more than 8 km higher than the lowest points in this area. This image was released on Feb. 27, 2012.
One year ago, MESSENGER became the first spacecraft ever to orbit Mercury. On March 18, 2012, MESSENGER completed its one-year primary mission and began a yearlong extended mission that includes a number of new scientific observation campaigns. The image shown here was acquired yesterday and is the first of MESSENGER's extended mission. Image released on March 18, 2012.
Although Mercury is replete with impact craters, it can be difficult to gauge their size in a meaningful way. This oblique image shows an unnamed crater that lies within the Rachmaninoff basin. It is a simple crater, characterized by its bowl-like shape, and lacks the central peak or peak ring of larger, complex craters. Image releases on Feb. 9, 2012.
In this region, we see the remnants of an inner peak ring, with hollows dusting the tops of the peaks in both the inner and outer rings. Also visible is the basin's main rim scarp beginning in the left corner of the image and extending to the southeast. The crater floor contains a number of regions of high-reflectance material, as well as polygonal valleys called graben (located near the top of the image, at the basin's center). Graben are formed by forces pulling apart the surface; these extensional forces are in contrast to the tectonic contraction we typically see all over Mercury and may be related to cooling of the smooth volcanic plains that cover the floor. Image released Feb. 6, 2012.
This impact crater, approximately 25 km (16 miles) in diameter, has been heavily modified by landslides. Portions of the crater’s walls detached and slumped towards the floor, producing terraces along the wall, landslide deposits on the crater floor, and modifying the crater’s outline from circular to irregular. The small bright spots on the landslide deposits (near the top of the image) may be hollows, similar to those seen in other impact craters on Mercury. Image released Feb. 4, 2012.
The Tolstoj basin is located in Mercury’s southern hemisphere, and is 355 km (220 miles) in diameter. This oblique image shows an elongate pit inside Tolstoj, a basin whose floor appears to have been flooded by lavas. The pit lacks the raised rim of an impact crater, and may have formed when magma withdrew from a shallow chamber, causing an unsupported area of the surface to collapse. The low-angle lighting in this image hides the floor of the pit, making it appear much deeper than it actually is. The pit is aligned approximately north-south. Image released Jan. 11, 2012.
This image, taken with the Wide Angle Camera (WAC), shows a bright rayed crater in Mercury's southern hemisphere. The rays, created when target material was ejected out onto the surface during the impact that formed the crater, will gradually fade over time due to the effects of Mercury's harsh space environment. The crater is deep enough that the local surface layers were penetrated, exposing low reflectance material (LRM) beneath. Image released on Feb. 6, 2012.
In this image, a portion of the 116 km- (73 mile-) diameter Abedin crater is visible. The floor of the crater is generally smooth, and hosts many small troughs that are interpreted to be graben. Graben form as the result of extensional (i.e. pull-apart) stresses, which in this case may have resulted from the cooling and solidification of either impact melt or volcanic fill inside Abedin, similar to that seen in other basins across Mercury. Image released Jan. 27, 2012.
This image, taken with the Narrow Angle Camera (NAC), gives us a spectacular close-up look at an unnamed complex crater in Mercury's northern hemisphere. At the top we see wall terraces containing ponds of impact melt. At the bottom is the crater's central peak, which displays bright material and possibly hollows near its summit. Image released Feb. 1, 2012.
Here we have two images of the impact crater named Debussy. The one on the left is from MESSENGER's monochrome base map. The one on the right is a complement from the stereo base map. Because of the differing viewing perspectives, the images can be combined to derive an elevation map (digital terrain model) of the surface. The left image was released on July 31, 2011. The right image was released on Jan. 19, 2012.
This image, captured by the Narrow Angle Camera (NAC), shows a number of trails of small craters. These trails, called secondary crater chains, are formed when ejecta from an initial impact are launched outward. As the ejecta fall back onto the planet's surface, they can form their own, often overlapping, small craters.
These hills make up a small portion of the southwestern rim of the 1550-km Caloris basin. This region was seen only with the sun high in the sky during MESSENGER's flybys of Mercury (and not at all by Mariner 10), so with the sun near the horizon in images like this one we are getting a great look at the surface's texture and topography.
This image is shown in a polar stereographic projection, with the south pole at the center, 0° longitude at the top, and 90° E longitude to the right. The image extends to -70° S latitude in all directions. MESSENGER has already photographed this region during the mission.
Interplanetary debris strikes the surface of Mercury with such force that portions of the rocky surface at the impact site melt. In this high-resolution image of Hokusai crater's interior and ejecta, you can see the smooth surfaces where impact melt ponded and cooled, forming new rocky plains.
This beautiful oblique view of a fresh impact crater was captured as the MESSENGER spacecraft slewed to the side to get a better look. The primary purpose for this slew was actually so that the Mercury Atmospheric and Surface Composition Spectrometer (MASCS) instrument could collect a reflectance spectrum of the crater's ejecta.
The unnamed crater in this image is almost exactly halfway between two nearby rayed craters: Qi Baishi and Hovnatanian. Qi Baishi is to the west and Hovnatanian is to the east - are these craters the source of the many elongated secondary craters in the scene? The orientation of the secondaries actually suggests another source to the north: the 225-km Mozart impact basin.
With the sun low in the sky to the west, the interiors of craters are completely hidden in shadow and even the smallest surface features cast shadows. In this light, the cratered interior of the Caloris basin takes on a rough and formidable appearance, though its volcanic plains are actually smoother than much of the planet.
This dramatic view was captured as the spacecraft's highly elliptical orbit positioned MESSENGER high above Mercury's southern hemisphere. The large basin with the smooth floor near the center right portion of the image is Pushkin.
MESSENGER images are enabling the story of Mercury's geologic history to be told. In this scene, there was once a crater that resembled the one in the upper right. Then, volcanic lava flooded the surface, burying the crater and leaving just an outline of the crater's rim, now seen as the "ghost crater" located in the lower left of this image. After extensive flooding in Mercury's north, additional cosmic bodies impacted Mercury's surface, creating the various sized craters seen here.
A long scarp runs vertically through the center of this image, deforming pre-existing craters along its length. At the bottom of this image, the scarp cuts through the wall and floor of the crater Ts'ai Wen-Chi (124 km diameter), named for the Han Dynasty poet and composer.
This May 4, 2011 image shows March crater, named for the 15th century Valencian poet Ausiàs March. The faint striations across the wall terraces in the lower right portion of the image may have been caused by landsliding or by emplacement of ejecta from another impact outside the field of view.
This Messenger view of Mercury's Degas crater (right) was obtained at a resolution of 90 meters per pixel. Impact melt coats the crater's floor; as the melt cooled and shrank, it formed the cracks observed across the crater. The Mariner 10 probe’s view of Degas is shown at left.
A photo mosaic of Mercury's northern plains, taken from orbit by NASA's Messenger spacecraft.
The rim of the double-ring basin Cervantes cuts through the middle of this NAC image, taken May 26, 2011. Cervantes has a diameter of 213 kilometers and was named in honor of the Spanish novelist, playwright, and poet Miguel de Cervantes (1547-1616), best known for his novel Don Quixote.
This image, taken on May 22, 2011, reveals previously unseen terrain near Mercury's north pole. There is a sharp boundary between smooth and rough terrain, but without seeing the neighboring areas, the boundary is difficult to interpret. Mosaicking this image with surrounding images will allow MESSENGER scientists to understand the geology of this region.
The craters in this scene, taken May 22, 2011, span a variety of degradation states. The sharp-looking crater near the center of the image has not undergone significant infilling or degradation, unlike the larger craters to the south. Its appearance indicates that it is relatively younger than these larger craters.
This spectacular image, taken on May 20, 2011, includes three large craters, approximately 12 km, 30 km, and 70 km in diameter. The largest crater is the oldest of the three, with the other two superposed on top of it. The 30-km-diameter crater exhibits a very interesting and unusual central peak structure.
This high-resolution image, taken on May 21, 2011, of a crater wall shows several slumps that occurred after the 20-km-diameter crater formed. The bottom-right corner of this image is located inside of the crater, and the upper-left corner is located outside of the crater rim.
This June 3, 2011 view off the limb of Mercury provides a unique oblique view of the crater Verdi. Topographic variation can be seen along Mercury's limb.
At a diameter of 100 km, the crater Atget is one of the largest craters within the Caloris basin. This targeted NAC, acquired on May 10, 2011, observation provides our first high-resolution view of Atget's low-reflectance floor and ejecta, which were likely excavated from beneath the surficial plains when Atget formed.
This WAC image, taken on May 4, 2011, is shown in a polar stereographic projection, with the south pole at the center, 0° longitude at the top, and 90° E longitude to the right. The image extends to -70° latitude in all directions. This image is the 15th of 89 total WAC images planned in support of MDIS's south polar monitoring campaign.
One of MDIS's imaging campaigns is to monitor the south polar region of Mercury. By imaging the polar region every four MESSENGER orbits as illumination conditions change, features that were in shadow on earlier orbits can be discerned and any permanently shadowed areas can be identified after repeated imaging over one solar day.
As the MESSENGER spacecraft sped over Mercury's north polar region on April 5, 2011, the NAC captured this image in very high resolution. This area is located north of Hokusai.
Pictured here are two named craters, Bek (32 km in diameter) and Lermontov (166 km in diameter) as seen on April 5, 2011. Bek's beautiful rays are indicative of its relative youth; Lermontov's floor is a suspected site of explosive volcanism, with irregular depressions and a distinct color signature.
NASA's Messenger spacecraft snapped this photo of Mercury's crater Boccaccio, named for 14th century Italian poet and novelist Giovanni Boccaccio, on March 30, 2011 during its early days orbiting the planet. The crater has a diameter of 88 miles (142 km) and was first photographed by NASA's Mariner 10 probe in 1974. Here, Messenger sees the Boccaccio crater under different lighting conditions, revealing its prominent central peak.
This oblique image, taken on April, 7, 2011, of Bek (32 km in diameter) is a higher-resolution NAC complement to yesterday's WAC image. The sharp crater rim is in contrast to its subdued surroundings, where crater ejecta scoured the surface and left behind many secondary craters.
The large, smooth area in the upper left is the floor of the crater Petrarch, as seen on April 5, 2011. The more rugged terrain around Petrarch has an unusual "hilly and lineated" texture that Mariner 10 team members called "weird terrain" upon seeing it for the first time. This area may have been modified by converging seismic waves and/or ejecta from the formation of the Caloris basin, which is located on the opposite side of the planet. In April 2011, MESSENGER viewed this area under differing lighting conditions than those seen during MESSENGER's second flyby and Mariner 10's first pass.
NASA's Messenger spacecraft acquired this image of Mercury's horizon as the spacecraft was moving northward along the first orbit during which MDIS camera instrument was activated, which occurred on March 29, 2011. Bright rays from Hokusai can be seen running north to south in the image. The right side of this image is about 750 miles (1,200 kilometers) in extent.
Artist's impression of the MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) spacecraft in orbit at Mercury.
This photo of Mercury from orbit from NASA's Messenger spacecraft reveals never-before-seen terrain as it appeared on March 29, 2011. The newly imaged surface is located in Mercury's north polar region, to the north of the bright, rayed crater Hokusai. Looking from the bottom of the image toward the top is looking southward. The bottom of the image is about 60 miles (100 km) across.
NASA's Messenger spacecraft spots an apparently fresh crater on Mercury during its early orbits on March 29, 2011. The crater (near image bottom) is about 4 miles (6.4 km) wide and is a beautiful example of a relatively small, simple, fresh impact feature on Mercury. It illustrates the textbook characteristics of a crater in its size range. The crater is nearly bowl-shaped, with just a small flat area in the center of its floor.
This photo is the first of Mercury from orbit as seen by the Narrow Angle Camera on NASA's Messenger spacecraft. The photo was taken on March 29, 2011 and shows a region of Mercury about 240 miles (390 km) across. Messenger is only the second spacecraft to visit Mercury and the first to orbit the planet.
The Mercury Atmospheric and Surface Composition Spectrometer (MASCS) collects spectra at ultraviolet to near-infrared wavelengths. Seen here are individual MASCS observations from the first Mercury solar day in orbit mapped over a mosaic of images obtained with MESSENGER’s Mercury Dual Imaging System (MDIS).
On March 29, 2011, NASA's Messenger spacecraft became the first probe ever to orbit Mercury. This image is the first color photo Mercury, showing the planet's southern polar region, acquired by Messenger from its new orbit. The Messenger probe arrived in orbit around Mercury on March 17 after three previous flybys of the planet.
This image was taken on April 15, 2011. In addition to the surface morphology base map, MDIS is currently acquiring a color base map during the mission's first 176 days. The color base map is composed of WAC images taken through eight different narrow-band color filters and will cover more than 90% of Mercury's surface at an average resolution of 1 km/pixel (0.6 miles/pixel) or better. In contrast to the imaging conditions best suited for seeing surface topography, the highest-quality color images of Mercury's surface are obtained when both the spacecraft and the Sun are overhead and shadows are limited.
This image of Mercury’s south polar region from NASA’s Messenger probe shows a map colored on the basis of the percentage of time that a given area is sunlit; areas appearing black in the map are regions of permanent shadow.
The highest-resolution radar image of Mercury’s south polar region made from the Arecibo Observatory (Harmon et al., Icarus, 211, 37-50, 2011) is shown in white on MESSENGER orbital images colorized by the illumination map. Radar-bright features in the Arecibo image all collocate with areas mapped as in permanent shadow, consistent with the proposal that radar-bright materials contain water ice.
