Next Mars Orbiter Will Launch August 10

Artist’s concept of Mars Reconnaissance Orbiter. Image credit: NASA/JPL. Click to enlarge
NASA’s next mission to Mars will examine the red planet in unprecedented detail from low orbit and provide more data about the intriguing planet than all previous missions combined. The Mars Reconnaissance Orbiter and its launch vehicle are nearing final stages of preparation at NASA’s Kennedy Space Center, Fla., for a launch opportunity that begins Aug. 10.

The spacecraft will examine Martian features ranging from the top of the atmosphere to underground layering. Researchers will use it to study the history and distribution of Martian water. It will also support future Mars missions by characterizing landing sites and providing a high-data-rate communications relay.

“Mars Reconnaissance Orbiter is the next step in our ambitious exploration of Mars,” said NASA’s director, Mars Exploration Program, Science Mission Directorate, Douglas McCuistion. “We expect to use this spacecraft’s eyes in the sky in coming years as our primary tools to identify and evaluate the best places for future missions to land.”

The spacecraft carries six instruments for probing the atmosphere, surface and subsurface to characterize the planet and how it changed over time. One of the science payload’s three cameras will be the largest-diameter telescopic camera ever sent to another planet. It will reveal rocks and layers as small as the width of an office desk. Another camera will expand the present area of high-resolution coverage by a factor of 10. A third will provide global maps of Martian weather.

The other three instruments are a spectrometer for identifying water-related minerals in patches as small as a baseball infield; a ground-penetrating radar, supplied by the Italian Space Agency, to peer beneath the surface for layers or rock, ice and, if present, water; and a radiometer to monitor atmospheric dust, water vapor and temperature.

Two additional scientific investigations will analyze the motion of the spacecraft in orbit to study the structure of the upper atmosphere and the Martian gravity field.

“We will keep pursuing a follow-the-water strategy with Mars Reconnaissance Orbiter,” said Dr. Michael Meyer, Mars exploration chief scientist at NASA Headquarters. “Dramatic discoveries by Mars Global Surveyor, Mars Odyssey and the Mars Exploration Rovers about recent gullies, near-surface permafrost and ancient surface water have given us a new Mars in the past few years. Learning more about what has happened to the water will focus searches for possible Martian life, past or present.”

Dr. Richard Zurek of NASA’s Jet Propulsion Laboratory, Pasadena, Calif., project scientist for the orbiter, said, “Higher resolution is a major driver for this mission. Every time we look with increased resolution, Mars has said, ‘Here’s something you didn’t expect. You don’t understand me yet.’ We’re sure to find surprises.”

The orbiter will reach Mars in March 2006. It will gradually adjust the shape of its orbit by aerobraking, a technique that uses the friction of careful dips into the planet’s upper atmosphere. For the mission’s 25-month primary science phase, beginning in November 2006, the planned orbit averages about 190 miles above the surface, more than 20 percent lower than the average for any of the three current Mars orbiters. The lower orbit adds to the ability to see Mars as it has never been seen before.

To get information from its instruments to Earth, the orbiter carries the biggest antenna ever sent to Mars and a transmitter powered by large solar panels. “It can send 10 times as much data per minute as any previous Mars spacecraft,” said JPL’s James Graf, project manager. “This increased return multiplies the value of the instruments by permitting increased coverage of the surface at higher resolution than ever before. The same telecommunications gear will be used to relay critical science data to Earth from landers.”

To loft so big a spacecraft, weighing more than two tons fully fueled, NASA will use a powerful Atlas V launch vehicle for the first time on an interplanetary mission.

The mission is managed by JPL, a division of the California Institute of Technology, Pasadena, for the NASA Science Mission Directorate. Lockheed Martin Space Systems, Denver, is the prime contractor for the project and built the spacecraft.

For information about Mars Reconnaissance Orbiter on the Web, visit http://www.nasa.gov/mro

Original Source: NASA News Release

Astrophoto: Callisto Transit by Leonard E. Mercer

Leonard E. Mercer took this image of Jupiter with Callisto Transit. Also Europa, Callisto, Ganymede & Io are visible in this image, from left to right. Leonard took this picture on the 22th of June 2005 using Nexstar 8i SE with Meade DSI.

Do you have photos you’d like to share? Post them to the Universe Today astrophotography forum or email them to me directly, and I might feature one in Universe Today.

Astrophoto: Lunar Trio By Tom Orff

Astrophotographer Tom Orff took this Moon picture of the three major lunar craters; Theophilus, Cyrillus and Catharina, on the 28th April 2001 from Shenandoah PA, USA. Image was acquired with a Starlight Xpress MX516 CCD camera and an 8″ Celestron Starhopper Dobsonian with a Dob Driver II at 3x prime focus (3600mm focal length (at f/18) with a TeleVue 3x barlow).

Do you have photos you’d like to share? Post them to the Universe Today astrophotography forum or email them to me directly, and I might feature one in Universe Today.

New Revelations About the Planet Under Your Feet

Artist’s conception of the Earth’s inner layers. Image credit: S. Jacobsen, M. Wysession, and G. Caras. Click to enlarge
Recently, seismologists have observed that the speed and direction of seismic waves in Earth?s lower mantle, between 400 and 1,800 miles below the surface, vary tremendously. ?I think we may have discovered why the seismic waves travel so inconsistently there,? stated Jung-Fu Lin.* Lin was with the Carnegie Institution?s Geophysical Laboratory at the time of the study and lead author of the paper published in the July 21, issue of Nature. ?Until this research, scientists have simplified the effects of iron on mantle materials. It is the most abundant transition metal in the planet and our results are not what scientists have predicted,? he continued. ?We may have to reconsider what we think is going in that hidden zone. It?s much more complex than we imagined.?

The crushing pressures in the lower mantle squeeze atoms and electrons so closely together that they interact differently from under normal conditions, even forcing spinning electrons to pair up in orbits. In theory, seismic-wave behavior at those depths may result from the vice-gripping pressure effect on the electron spin-state of iron in lower-mantle materials. Lin?s team performed ultra high-pressure experiments on the most abundant oxide material there, magnesiow?stite (Mg,Fe)O, and found that the changing electron spin states of iron in that mineral drastically affect the elastic properties of magnesiow?stite. The research may explain the complex seismic wave anomalies observed in the lowermost mantle.

As co-author of the study Viktor Struzhkin elaborated: ?This is the first study to demonstrate experimentally that the elasticity of magnesiow?stite significantly changes under lower-mantle pressures ranging from over 500,000 to 1 million times the pressure at sea level (1 atmosphere). Magnesiow?stite, containing 20% iron oxide and 80% magnesium oxide, is believed to constitute roughly 20% of the lower mantle by volume. We found that when subjected to pressures between 530,000 and 660,000 atmospheres the iron?s electron spins went from a high-spin state (unpaired) to a low-spin state (spin-paired). While monitoring the spin-state of iron, we also measured the rate-of-change in the volume (density) of magnesiow?stite through the electronic transition. That information enabled us to determine how seismic velocities will vary across the transition.?

?Surprisingly, bulk seismic waves travel about 15% faster once the electrons of iron are spin-paired in the magnesium-iron oxide,? commented co-author Steven Jacobsen. ?The measured velocity jump across the transition might, therefore, be detectable seismically in the deep mantle.? The experiments were conducted inside a diamond-anvil pressure cell using the intense X-ray light source at the nation’s third-generation synchrotron source, Argonne National Laboratory near Chicago.

?The mysterious lower mantle region can?t be sampled directly. So we have to rely on experimentation and theory. Since what happens in Earth?s interior affects the dynamics of the entire planet, it?s important for us to find out what is causing the unusual behavior of seismic waves in that region,? stated Lin. ?Up to now, earth scientists have understood Earth?s interior by only considering pure oxides and silicates. Our results simply point out that iron, the most abundant transition metal throughout the entire Earth, gives rise to very complex properties in that deep region. We look forward to our next experiments to see if we can refine our understanding of what is happening there,? he concluded.

Original Source: Carnegie Institution News Release