Home | Site Map | What's New | Image Index | Copyright | Posters | ScienceViews | Science Fiction Timelines |

PHOTO INDEX OF
PRIMARY TARGETS
ASTEROIDS
COMETS
EARTH
JUPITER
KUIPER BELT
MARS
MERCURY
METEORITES
NEPTUNE
OORT CLOUD
PLUTO
SATURN
SOLAR SYSTEM
SPACE
SUN
URANUS
VENUS
ORDER PRINTS

OTHER PHOTO INDEXES
ALL TARGETS
PHOTO CATEGORIES

SCIENCEVIEWS
AMERICAN INDIAN
AMPHIBIANS
BIRDS
BUGS
FINE ART
FOSSILS
THE ISLANDS
HISTORICAL PHOTOS
MAMMALS
OTHER
PARKS
PLANTS
RELIGIOUS
REPTILES
SCIENCEVIEWS PRINTS

"The Spider" - Radial Troughs within Caloris

Target Name:  Mercury
Spacecraft:  MESSENGER
Produced by:  NASA/JHUAPL
Copyright: Copyright Free
Date Released: 30 January 2008

Related Documents
Download Options

NameTypeWidth x HeightSize
VSS00092.jpgJPEG640 x 43279K
VSS00092.jpgJPEG3000 x 20253M
VSS00092.tifTIFF3000 x 20254M

The Narrow Angle Camera of the Mercury Dual Imaging System (MDIS) on the MESSENGER spacecraft obtained high-resolution images of the floor of the Caloris basin on January 14, 2008. Near the center of the basin, an area unseen by Mariner 10, this remarkable feature - nicknamed "the spider" by the science team - was revealed. A set of troughs radiates outward in a geometry unlike anything seen by Mariner 10. The radial troughs are interpreted to be the result of extension (breaking apart) of the floor materials that filled the Caloris basin after its formation. Other troughs near the center form a polygonal pattern. This type of polygonal pattern of troughs is also seen along the interior margin of the Caloris basin. An impact crater about 40 km (~25 miles) in diameter appears to be centered on "the spider." The straight-line segments of the crater walls may have been influenced by preexisting extensional troughs, but some of the troughs may have formed at the time that the crater was excavated.

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

Copyright © 1995-2016 by Calvin J. Hamilton. All rights reserved.