(From west to east)

• Vesta is in the constellation of Aquarius.
• Eunomia is in the constellation of Perseus.
• Eros is in the constellation of Leo.
• Hebe is in the constellation of Leo.

• Information about the Minor Planets can be found at the Minor Planet Observer website.

"On this high-altitude encounter of Titan, the imaging science subsystem (ISS) will perform high-resolution observations around closest-approach along the anti-Saturnian and trailing hemispheres at mid- to high southern latitudes.

This is one of ISS' so-called "10-pointer" flybys, i.e. one of the two scientifically most significant Titan fly-bys for ISS during the Solstice mission. As the lead instrument on the inbound approach to Titan, the composite infrared spectrometer (CIRS) instrument views Titan at various distances and spectral resolutions to make maps of atmospheric and surface temperature. After closest approach, RADAR will do radiometry of the sub-Saturn hemisphere. Outbound, the visible and infrared mapping spectrometer (VIMS) will perform stellar occultations of the stars CW Leo and R Leo, which will constrain the composition and the spectral properties of Titan's atmosphere. During the flyby, the radio and plasma wave science (RPWS) will measure thermal plasmas in Titan's ionosphere and surrounding environment, search for lightning in Titan's atmosphere, and investigate the interaction of Titan with Saturn's magnetosphere."

Cassini Imaging Team

"Boulder, Colo. - Dec. 20, 2011 - The new and highly sensitive Cosmic Origins Spectrograph aboard the Hubble Space Telescope has discovered a strong ultraviolet-wavelength absorber on Pluto's surface, providing new evidence that points to the possibility of complex hydrocarbon and/or nitrile molecules lying on the surface, according to a paper recently published in the Astronomical Journal by researchers from Southwest Research Institute and Nebraska Wesleyan University.

Such chemical species can be produced by the interaction of sunlight or cosmic rays with Pluto's known surface ices, including methane, carbon monoxide and nitrogen."

LORRI Looks Back

New Horizons gallery

Find New Horizons in the iTunes App Store here.

"PASADENA, Calif. - NASA's Dawn spacecraft has sent back the first images of the giant asteroid Vesta from its low-altitude mapping orbit. The images, obtained by the framing camera, show the stippled and lumpy surface in detail never seen before, piquing the curiosity of scientists who are studying Vesta for clues about the solar system's early history. At this detailed resolution, the surface shows abundant small craters, and textures such as small grooves and lineaments that are reminiscent of the structures seen in low-resolution data from the higher-altitude orbits. Also, this fine scale highlights small outcrops of bright and dark material. A gallery of images can be found online at: http://www.nasa.gov/mission_pages/dawn/multimedia/gallery-index.html."

"The crater at the center of Wednesday's MESSENGER image of the day is named Dickens, after Charles Dickens, the English novelist who lived from 1812 to 1870. Among Dickens' most famous works is A Christmas Carol, the story of miserly Ebenezer Scrooge and his tortured journey to a more humanitarian and generous nature.

This image was acquired as part of the Mercury Dual Imaging System's (MDIS) high-resolution surface morphology base map. The surface morphology base map will cover more than 90% of Mercury's surface with an average resolution of 250 meters per pixel (0.16 miles per pixel). Images acquired for the surface morphology base map typically have off-vertical Sun angles (i.e., high incidence angles) and visible shadows so as to reveal clearly the topographic form of geologic features.

Since entering orbit around Mercury on March 18, 2011, the MDIS has beamed back more than 70,000 images of the surface of the planet. The mission's imaging team has been releasing at least one new image every weekday. They are available online at http://messenger.jhuapl.edu/gallery/sciencePhotos/. During the one-year primary mission, MDIS is scheduled to acquire more than 75,000 images in support of MESSENGER's science goals."

"PASADENA, Calif. -- NASA's car-sized Curiosity rover has begun monitoring space radiation during its 8-month trip from Earth to Mars. The research will aid in planning for future human missions to the Red Planet.

Curiosity launched on Nov. 26 from Cape Canaveral, Fla., aboard the Mars Science Laboratory. The rover carries an instrument called the Radiation Assessment Detector (RAD) that monitors high-energy atomic and subatomic particles from the sun, distant supernovas and other sources.

These particles constitute radiation that could be harmful to any microbes or astronauts in space or on Mars. The rover also will monitor radiation on the surface of Mars after its August 2012 landing.

"RAD is serving as a proxy for an astronaut inside a spacecraft on the way to Mars," said Don Hassler, RAD's principal investigator from the Southwest Research Institute in Boulder, Colo. "The instrument is deep inside the spacecraft, the way an astronaut would be. Understanding the effects of the spacecraft on the radiation field will be valuable in designing craft for astronauts to travel to Mars."

Previous monitoring of energetic-particle radiation in space has used instruments at or near the surface of various spacecraft. The RAD instrument is on the rover inside the spacecraft and shielded by other components of Mars Science Laboratory, including the aeroshell that will protect the rover during descent through the upper atmosphere of Mars."

SPIRIT UPDATE: Spirit Remains Silent at Troy - sols 2621-2627, May 18-24, 2011:

"No communication has been received from Spirit since Sol 2210 (March 22, 2010).

More than 1,300 commands were radiated to Spirit as part of the recovery effort in an attempt to elicit a response from the rover. No communication has been received from Spirit since Sol 2210 (March 22, 2010). The project concluded the Spirit recovery efforts on May 25, 2011. The remaining, pre-sequenced ultra-high frequency (UHF) relay passes scheduled for Spirit on board the Odyssey orbiter will complete on June 8, 2011.

Total odometry is unchanged at 7,730.50 meters (4.80 miles)."

OPPORTUNITY UPDATE: Positioned at Candidate Site for Winter - sols 2813-2817, December 23-27, 2011:

"Opportunity is positioned at a candidate site for Mars' southern hemisphere winter. The rover is at the north end of 'Cape York' on the rim of Endeavour Crater, tilted about 15 degrees to the north for favorable solar energy production.

Opportunity experienced anomalously high current in the right-front wheel on Sol 2808 (Dec. 17, 2011). Diagnostics on Sols 2810 and 2812 (Dec. 20 and 22, 2011) indicated a nominal wheel and drive actuator with the terrain being the indicated explanation for the high current. On Sol 2816 (Dec. 26, 2011), the rover performed an 8-inch (0.2-meter) diagnostic backward drive. The drive completed successfully with Opportunity maintaining its 15-degree northerly tilt, sufficient for the winter period.

The plan ahead is to conduct some contact measurements with the instruments on the robotic arm to see if this location offers substantive in-situ science opportunities during the winter months. Opportunity will also begin a radio Doppler tracking campaign at the start of the new year.

As of Sol 2817 (Dec. 27, 2011), solar array energy production was 290 watt-hours with an atmospheric opacity (Tau) of 0.685 and a solar array dust factor of 0.475.

Total odometry as of Sol 2816 (Dec. 26, 2011) is 21.35 miles (34,361.37 meters)."

Landing sites

"An improved tool debuts today for viewing channels, dunes, boulders and other features revealed in the huge image files from the High Resolution Imaging Science Experiment (HiRISE) camera on NASA's Mars Reconnaissance Orbiter. The new tool, HiView, offers the best way to take a personal, virtual hike through any of thousands of square miles of Mars observed by HiRISE, seeing details as small as a desk. To watch the tutorial video and download the free HiView application, go to: http://www.uahirise.org/hiview/."

MARS RECONNAISSANCE ORBITER HIRISE IMAGES
All of the HiRISE images are archived here.

Global Martian Map

"A simulated fly-through using the newly assembled imagery is available online.

The fly-through plus tools for wandering across and zooming into the large image are at THEMIS."

Daily Mars Odyssey THEMIS Images
Can be found at the Thermal Emission Imaging System (THEMIS) website.

The Odyssey data are available through a new online access system established by the Planetary Data System.