Mars Global Digital Dune Database: MC2MC29 The Mars Global Digital Dune Database presents data and describes the methodology used in creating the database. The database provides a comprehensive and quantitative view of the geographic distribution of moderate- to large-size dune fields from 65° N to 65° S latitude and encompasses ~ 550 dune fields. The database will be expanded to cover the entire planet in later versions. Although we have attempted to include all dune fields between 65° N and 65° S, some have likely been excluded for two reasons: 1) incomplete THEMIS IR (daytime) coverage may have caused us to exclude some moderate- to large-size dune fields or 2) resolution of THEMIS IR coverage (100m/pixel) certainly caused us to exclude smaller dune fields. The smallest dune fields in the database are ~ 1 km2 in area. While the moderate to large dune fields are likely to constitute the largest compilation of sediment on the planet, smaller stores of sediment of dunes are likely to be found elsewhere via higher resolution data. Thus, it should be noted that our database excludes all small dune fields and some moderate to large dune fields as well. Therefore the absence of mapped dune fields does not mean that such dune fields do not exist and is not intended to imply a lack of saltating sand in other areas.
A small northern New Mexico village now shares its name with a 5-mile-wide asteroid crater on Mars. The International Astronomical Union recently named the Martian crater for the village of Chupadero, which sits at the foothills of the Sangre de Cristo Mountains. The name was provided by Brad Smith, a semi-retired New Mexico astronomy professor who sits on the IAU committee that names Martian craters.
Dark sand dunes on Mars resemble the ripples on chocolate candy bars in a recently released image taken by the High Resolution Imaging Science Experiment (HiRISE) camera on NASA's Mars Reconnaissance Orbiter spacecraft. The dunes lie on the floor of a 300-kilometre-wide crater called Herschel. The structures, called barchan dunes, are often found in sandy deserts on Earth. Researchers suspect the steep-faced dunes on Mars are composed of basaltic sand. Their grooved texture indicates that the sand may have been cemented together somehow and then sculpted into crescent shapes by the wind. Their orientation reveals that the strongest wind in the region blows from north to south.
Expand (134kb, 560 x 1257) Credit NASA/JPL/University of Arizona
A Mars-orbiting satellite recently spotted seven dark spots near the planet's equator that scientists think could be entrances to underground caves. The football-field sized holes were observed by Mars Odyssey's Thermal Emission Imaging System (THEMIS) and have been dubbed the seven sisters Dena, Chloe, Wendy, Annie, Abbey, Nikki and Jeanne after loved ones of the researchers who found them. The potential caves were spotted near a massive Martian volcano, Arisa Mons. Their openings range from about 330 to 820 feet (100 to 250 meters) wide, and one of them, Dena, is thought to extend nearly 430 feet (130 meters) beneath the planet's surface.
Title: Infrared Brightness Temperature of Mars, 1983-2103 Authors: E. L. Wright (UCLA)
The predicted infrared brightness temperature of Mars using the 1976 model of Wright is tabulated here for the period 1983 to 2103. This model was developed for far-infrared calibration, and is still being used for JCMT calibration.
This map shows the thickness of the south polar layered deposits of Mars, an ice-rich geologic unit that was probed by the Mars Advanced Radar for Subsurface and Ionospheric Sounding (MARSIS). The MARSIS radar is an instrument on the European Space Agency’s Mars Express orbiter. The thickness of the layered deposits was determined by measuring the time delay between radar echoes from the surface and those from the lower boundary, or "bed", of the deposits. The radar data indicate that the deposit, larger than Texas in area, is more than 3.7 kilometres thick in places, and that the material consists of nearly pure water ice with only a small component of dust.
The map was generated by comparing the elevation of the bed as determined by MARSIS with the high-resolution map of surface topography obtained by the Mars Orbiter Laser Altimeter aboard NASA's Mars Global Surveyor orbiter. The thickness of the layered deposits is shown by colours, with purple representing the thinnest areas, and red the thickest. The total volume of ice in the layered deposits is equivalent to a water layer 11 metres deep, if spread evenly across the planet. The boundary of the layered deposits was mapped by scientists from the U.S. Geological Survey. The dark circle in the upper centre is the area poleward of 87 degrees south latitude, where MARSIS data cannot be collected. The map covers an area 1,670 by 1,800 kilometres.