PIA12269: A Newly Pictured Pit-Floor Crater
 Target Name:  Mercury
 Is a satellite of:  Sol (our sun)
 Mission:  MESSENGER
 Spacecraft:  MESSENGER
 Instrument:  MDIS - Narrow Angle
 Product Size:  424 x 458 pixels (w x h)
 Produced By:  Johns Hopkins University/APL
 Full-Res TIFF:  PIA12269.tif (194.6 kB)
 Full-Res JPEG:  PIA12269.jpg (32.9 kB)

Click on the image above to download a moderately sized image in JPEG format (possibly reduced in size from original)

Original Caption Released with Image:

The unnamed crater in the center of the image, viewed at close range for the first time yesterday during MESSENGER's third flyby of Mercury, displays an arc-shaped depression known as a pit crater on its floor. This pit crater is similar to those seen in crater Beckett and crater Gibran imaged during MESSENGER's first Mercury flyby in January 2008 and in crater Lermontov, observed by both Mariner 10 and by MESSENGER during its second flyby (October 2008). Impact craters on Mercury that host pit craters in their interiors have been named pit-floor craters. Unlike impact craters, pit craters are rimless, often irregularly shaped, and steep-sided, and they display no associated ejecta or lava flows but are typically distinctive in color. Thought to be evidence of shallow magmatic activity, pit craters may have formed when subsurface magma drained elsewhere and left a roof area unsupported, leading to collapse and the formation of the pit. In this example, the southern area of the pit appears to have two or more floor levels. The discovery of multiple pit-floor craters augments a growing body of evidence that volcanic activity was widespread in the geologic evolution of Mercury's crust.

Date Acquired: September 29, 2009
Image Mission Elapsed Time (MET): 162741014
Instrument: Narrow Angle Camera (NAC) of the Mercury Dual Imaging System (MDIS)
Resolution: 690 meters/pixel (0.43 miles/pixel)
Scale: The pit-floor crater in the center of this image is about 110 kilometers (69 miles) in diameter
Spacecraft Altitude: 27,000 kilometers (16,800 miles)

These images are from MESSENGER, a NASA Discovery mission to conduct the first orbital study of the innermost planet, Mercury. For information regarding the use of images, see the MESSENGER image use policy.

Image Credit:
NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington

Image Addition Date: