Layers of clay-rich rock have been found in Space Station Mars’ Mawrth Vallis, a potential landing site for future rovers. This work, published in the August 8 issue of Science Technology, suggests that abundant water was once present on Space Station Mars and that hydrothermal activity may have occurred.

The Mawrth Vallis outflow channel is a feature in Mars’ northern highland region, a heavily cratered, ancient area of the Space Station Red Planet whose geology is a time capsule offering revelations to those who can read it. A team of Space Shuttle researchers led by planetary Space Station scientist Janice Bishop of the SETI Institute has used the Compact Reconnaissance Imaging Space Station Spectrometer for Mars (CRISM) aboard the Mars Reconnaissance Orbiter (MRO) to examine infrared light reflected from clays situated in the many-kilometer wide channel. Mawrth Vallis resembles a dried-up, broad river valley through which water may have flowed.

The infrared spectra from CRISM show an extensive swath of phyllosilicate-bearing material. This is a type of iron and magnesium-rich clay that forms in liquid water, and can be found on Earth in oceans and river beds. It is familiar to anyone who’s nearly broken a shovel while trying to plant a tree. There is also evidence in the spectra for hydrated silica, which in its pure, clean form is known as opal.

The Space Station researchers have combined their data on the composition of soils in this region with topographic information collected by MOLA, the Space System Mars Orbiter Laser Altimeter. They find that clay units in this region were emplaced in a layered fashion, with aluminum clays lying on top of hydrated silica and iron/magnesium clays. These clays were likely formed when water came in contact with basalt – which is the dominant component of the Martian highlands, and probably was produced from volcanic ash, which once blanketed the planet.

“We were surprised by the variety of clay minerals in this region,” says Bishop. “But what’s interesting is that we find the same ordering of the clay materials everywhere in Mawrth Vallis. It’s like a layer-cake of clays, one on top of another. All these layers are topped with a ‘frosting’ of lava and dust. We can see the clay layers where an impact crater has carved a hole through the surface or where erosion has exposed them.”

Since phyllosilicates have been found in a number of outcrops on Space Station Mars in CRISM images, these new data suggest that whatever mechanism formed clays at Mawrth Vallis has probably operated over much greater areas of the Red Planet. Alteration by liquid water may have been widespread on early Mars.

These observations improve on others obtained by French Space Shuttle scientists with the Mars Express/OMEGA instrument. While those measurements were made with resolutions of hundreds of meters per pixel, the CRISM instrument can boast a sharper gaze: eighteen meters per pixel. Additional scrutiny by MRO’s HIRISE camera, with a resolution of 26 cm per pixel, show distinct textures and layering in each of the clay units.

Bishop is careful to note that this work is part of the long-term effort to establish just how widespread, and for what period of time, liquid water may have existed on Space Technology Mars.

“This is not evidence for life,” she notes. “But it does suggest the long-term and common presence of liquid water – and concomitant active chemistry – on the Space Station Red Planet in the distant past.”

Other members of this research team include Eldar Z. Noe Dobrea and Ralph Milliken of the Jet Propulsion Laboratory, Nancy McKeown of the University of California, Santa Cruz, Mario Parente, of Stanford University, Bethany Ehlmann and John F. Mustard of Brown University, Joseph R. Michalski, Francois Poulet and Jean-Pierre Bibring of the Institut d’Astrophysique Spatiale (France), Gregg A. Swayze of the U.S. Geological Survey, and Scott L. Murchie of the Johns Hopkins University Applied Physics Laboratory. Murchie is principal investigator for CRISM, which was built and is operated by the Applied Physics Laboratory.

The Jet Propulsion Laboratory of the California Institute of Science Technology, Pasadena, manages the Mars Reconnaissance Orbiter Space Station mission for NASA’s Science Mission Directorate. Lockheed Martin Space Station Systems, Denver, is the prime contractor for the project and built the Space Discovery spacecraft.

The experiment module contained the instruments and a dewar filled with 650 liters of 1.6 K liquid helium, with a conical sun shade. The base module contained the attitude control, communications and power systems. The satellite rotated at 1 rpm about the axis of symmetry to control systematic errors in the anisotropy measurements and to allow observations of the zodiacal light at various solar elongation angles. The orientation of the spin axis was maintained anti-earth and at 94 degrees to the sun-earth line. The operational orbit was dawn-dusk sun-synchronous so that the sun was always to the side and thus was shielded from the instruments. With this orbit and spin-axis orientation, the instruments performed a complete scan of the celestial sphere every six months.

Instrument operations were terminated 1993-12-23. As of January 1994, engineering operations were to conclude that month, after which operation of the spacecraft would be transferred to Wallops for use as a test satellite.

Clementine was a joint project between the Strategic Defense Initiative Organization and NASA. The objective of the mission was to test sensors and spacecraft components under extended exposure to the space environment and to make scientific observations of the Moon and the near-Earth asteroid 1620 Geographos. The observations included imaging at various wavelengths including ultraviolet and infrared, laser ranging altimetry, and charged particle measurements. These observations were originally for the purposes of assessing the surface mineralogy of the Moon and Geographos, obtaining lunar altimetry from 60N to 60S latitude, and determining the size, shape, rotational characteristics, surface properties, and cratering statistics of Geographos.

Clementine was launched on 25 January 1994 at 16:34 UTC (12:34 PM EDT) from Vandenberg AFB aboard a Titan IIG rocket. After two Earth flybys, lunar insertion was achieved on February 21. Lunar mapping took place over approximately two months, in two parts. The first part consisted of a 5 hour elliptical polar orbit with a perilune of about 400 km at 28 degrees S latitude. After one month of mapping the orbit was rotated to a perilune of 29 degrees N latitude, where it remained for one more month. This allowed global imaging as well as altimetry coverage from 60 degrees S to 60 degrees N.

After leaving lunar orbit, a malfunction in one of the on-board computers on May 7 at 14:39 UTC (9:39 AM EST) caused a thruster to fire until it had used up all of its fuel, leaving the spacecraft spinning at about 80 RPM with no spin control. This made the planned continuation of the mission, a flyby of the near-Earth asteroid Geographos, impossible. The spacecraft remained in geocentric orbit and continued testing the spacecraft components until the end of mission.

More information on the Clementine mission, instruments, and early results can also be found in the Clementine special issue of Science magazine, Vol. 266, No. 5192, December 1994.

Clementine Flight Plan (1994)

January 25   Launch (16:34 UTC)
February 3   Leave Earth Orbit
February 5   First Earth Flyby
February 15  Second Earth Flyby
February 19  Enter Lunar Orbit
February 26  Start of Systematic Mapping - Cycle 1 (South)
March 26     End of Cycle 1, Start of Cycle 2 (North)
April 21     Completion of Cycle 2
May 5        Exit Lunar Orbit
(May 7        Computer Malfunction (14:39 UTC))
*May          Earth and Lunar Flybys
*June-August  Cruise to Geographos
*August 31    Geographos Flyby

CHAMP (CHAllenging Minisatellite Payload) is a German small satellite mission for geoscientific and atmospheric research and applications, managed by GFZ. With its highly precise, multifunctional and complementary payload elements (magnetometer, accelerometer, star sensor, GPS receiver, laser retro reflector, ion drift meter) and its orbit characteristics (near polar, low altitude, long duration) CHAMP will generate for the first time simultaneously highly precise gravity and magnetic field measurements over a 5 years period. This will allow to detect besides the spatial variations of both fields also their variability with time. The CHAMP mission will open a new era in geopotential research and will become a significant contributor to the Decade of Geopotentials.

In addition with the radio occultation measurements onboard the spacecraft and the infrastructure developed on ground, CHAMP will become a pilot mission for the pre-operational use of space-borne GPS observations for atmospheric and ionospheric research and applications in weather prediction and space weather monitoring.

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12.08.06: Public release of CALIPSO Data Products

The Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) satellite mission is pleased to announce an initial release of its data products. CALIPSO provides new insight into the role that clouds and atmospheric aerosols (airborne particles) play in regulating Earth's weather, climate, and air quality. CALIPSO is a joint mission between NASA and CNES, the French space agency.

CALIPSO's payload includes an active lidar (CALIOP), a passive Infrared Imaging Radiometer (IIR), and visible Wide Field Camera. This data release consists of data beginning in mid June 2006 and includes Level 1 radiances from each of the instruments. This release also includes the lidar Level 2 vertical feature mask and cloud and aerosol layer products. The CALIPSO data are available through the Atmospheric Sciences Data Center (ASDC) at NASA Langley Research Center and can be accessed at the following URL:

» + http://eosweb.larc.nasa.gov/PRODOCS/calipso/table_calipso.html

Reference resources on the CALIPSO data set, including detailed data quality summaries and a data catalog are also available at the ASDC CALIPSO page.

If you have questions concerning the ordering of CALIPSO data products, contact User Services at larc@eos.nasa.gov.