(From west to east)

• Vesta is in the constellation of Cetus.
• Pallas is in the constellation of Lepus.
• Euterpe is at opposition on the 3rd in the constellation of Cancer.
• Amphitrite is in the constellation of Virgo.
• Irene is in the constellation of Virgo.
• Information about the Minor Planets can be found at the Minor Planet Observer website.

"Recent images of Titan from NASAÕs Cassini spacecraft affirm the presence of lakes of liquid hydrocarbons by capturing changes in the lakes brought on by rainfall. For several years, Cassini scientists have suspected that dark areas near the north and south poles of SaturnÕs largest satellite might be liquid-filled lakes. An analysis published today in the journal Geophysical Research Letters of recent pictures of Titan's south polar region reveals new lake features not seen in images of the same region taken a year earlier. The presence of extensive cloud systems covering the area in the intervening year suggests that the new lakes could be the result of a large rainstorm and that some lakes may thus owe their presence, size and distribution across TitanÕs surface to the moonÕs weather and changing seasons.

The high-resolution cameras of CassiniÕs Imaging Science Subsystem (ISS) have now surveyed nearly all of TitanÕs surface at a global scale. An updated Titan map, being released today by the Cassini Imaging Team, includes the first near-infrared images of the leading hemisphere portion of TitanÕs northern "lake districtÓ captured on Aug. 15-16, 2008. (The leading hemisphere of a moon is that which always points in the direction of motion as the moon orbits the planet.) These ISS images complement existing high-resolution data from CassiniÕs Visible and Infrared Mapping Spectrometer (VIMS) and RADAR instruments."

Cassini Imaging Team

On the anniversary of New Horizons' launch from Cape Canaveral Air Force Station, Fla., on January 19, 2006, mission team members reflect on liftoff, a busy first three years of flight and the ongoing voyage to Pluto and beyond.

Countdown to Liftoff

"To Ralph McNutt, of the Johns Hopkins Applied Physics Laboratory (APL), launch wasnÕt just a beginning Ð it was the culmination of a hard-fought, nearly two-decade-long battle in the scientific community to secure a mission to the ninth planet.

"When the announcer hit 'zero' and the Atlas V rocket began plowing its way through the wispy skin of this pale blue dot we call home, it was a special moment," says McNutt, principal investigator of the New Horizons Pluto Energetic Particle Spectrometer Science Investigation, or PEPSSI. "We really were on the way, and no one could stop us from taking that path to new lands."

Science team co-investigator Richard Binzel of the Massachusetts Institute of Technology remembers the run-up to launch, a four-year concert of spacecraft design, build and testing, and mission planning that had to reach its crescendo by January 2006, in time to meet a month-long launch period and take advantage of an opportunity to use Jupiter's gravity as a slingshot toward deeper space.

"The transition from launch to flight is truly phenomenal," Binzel says. ÒBefore launch, the clock looms so large. Everything has to be ready at the launch window, or else! In cruise phase the pace of hard work continues, but now the responsibility feels different. We know New Horizons will reach Pluto!"

New Horizons gallery."

"NASA's Dawn spacecraft shut down its ion propulsion system today as scheduled. The spacecraft is now gliding toward a Mars flyby in February of next year.

"Dawn has completed the thrusting it needs to use Mars for a gravity assist to help get us to Vesta," said Marc Rayman, Dawn's chief engineer, of NASA's Jet Propulsion Laboratory, Pasadena, Calif. "Dawn will now coast in its orbit around the sun for the next half a year before we again fire up the ion propulsion system to continue our journey to the asteroid belt."

Dawn's ion engines may get a short workout next January to provide any final orbital adjustments prior to its encounter with the Red Planet. Ions are also scheduled to fly out of the propulsion system during some systems testing in spring. But mostly, Dawn's three ion engines will remain silent until June, when they will again speed Dawn toward its first appointment, with asteroid Vesta."

"On December 26, the MESSENGER spacecraft will have traveled three billion miles since its launch, marking somewhat more than 60 percent of the probe's journey toward its destination to be inserted into orbit about Mercury.

"That MESSENGER's odometer reading has reached another major milestone reminds us of the long and complex route that our spacecraft must follow," offers Principal Investigator Sean Solomon, of the Carnegie Institution of Washington. "The year now ending has seen the first two spacecraft flybys of the innermost planet in more than three decades, encounters that have yielded a rich lode of new observations. The journey is far from over, but MESSENGER has a skilled team to guide it the rest of the way."

Mercury orbits deep within the Sun's gravity well. So, even though the planet can be as close as 82 million kilometers (51 million miles) from Earth, getting the probe into orbit around Mercury depends on an innovative trajectory using the gravity of Earth, Venus, and Mercury itself to slow and shape the probe's descent into the inner solar system. On its 4.9 billion-mile journey to becoming the first spacecraft to orbit the planet Mercury, MESSENGER has flown by Earth once, Venus twice, and Mercury twice. Still to come is one more flyby of Mercury in late September 2009.

Today the spacecraft entered its fourth superior solar conjunction of the mission, placing it on the opposite side of the Sun from Earth. (To see where MESSENGER is now, visit http://messenger.jhuapl.edu/whereis/index.php.) The Sun-Earth-probe angle will be between 2° and 3° until January 6, 2009, so during the next two weeks there will be no communication with the spacecraft."

"An international team of scientists who analyzed data from the Gamma Ray Spectrometer onboard NASA's Mars Odyssey reports new evidence for the controversial idea that oceans once covered about a third of ancient Mars.

"We compared Gamma Ray Spectrometer data on potassium, thorium and iron above and below a shoreline believed to mark an ancient ocean that covered a third of Mars' surface, and an inner shoreline believed to mark a younger, smaller ocean," said University of Arizona planetary geologist James M. Dohm, who led the international investigation.

"Our investigation posed the question, Might we see a greater concentration of these elements within the ancient shorelines because water and rock containing the elements moved from the highlands to the lowlands, where they eventually ponded as large water bodies?" Dohm said."

"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.

Mars Rover Team Diagnosing Unexpected Behavior UPDATED on Jan. 29: Spirit Working Well While Diagnostics Continue

"Diagnostic activities performed by Spirit on Thursday, Jan. 29 narrowed the range of factors that may have contributed to its unexpected behavior earlier in the week. No clear explanation has been established yet. Spirit is healthy and responding to commands. It recorded and returned images of nearby scientific targets. The rover team plans further diagnostics on Friday of Spirit's inertial measurement unit -- a combined gyroscope-and-accelerometer device that measures rover movements and attitude. Spirit may resume driving over the weekend.

PASADENA, Calif. - The team operating NASA's Mars Exploration Rover Spirit plans diagnostic tests this week after Spirit did not report some of its weekend activities, including a request to determine its orientation after an incomplete drive.

On Sunday, during the 1,800th Martian day, or sol, of what was initially planned as a 90-sol mission on Mars, information radioed from Spirit indicated the rover had received its driving commands for the day but had not moved. That can happen for many reasons, including the rover properly sensing that it is not ready to drive. However, other behavior on Sol 1800 was even more unusual: Spirit apparently did not record the day's main activities into the non-volatile memory, the part of its memory that persists even when power is off.

On Monday, Spirit's controllers at NASA's Jet Propulsion Laboratory in Pasadena, Calif., chose to command the rover on Tuesday, Sol 1802, to find the sun with its camera in order to precisely determine its orientation. Not knowing its orientation could have been one possible explanation for Spirit not doing its weekend drive. Early Tuesday, Spirit reported that it had followed the commands, and in fact had located the sun, but not in its expected location.

"We don't have a good explanation yet for the way Spirit has been acting for the past few days," said JPL's Sharon Laubach, chief of the team that writes and checks commands for the rovers. "Our next steps will be diagnostic activities."

Among other possible causes, the team is considering a hypothesis of transitory effects from cosmic rays hitting electronics. On Tuesday, Spirit apparently used its non-volatile memory properly.

Despite the rover's unexplained behavior, Mars Exploration Rovers Project Manager John Callas of JPL said Wednesday, "Right now, Spirit is under normal sequence control, reporting good health and responsive to commands from the ground."

JPL, a division of the California Institute of Technology, Pasadena, manages the Mars Exploration Rover project for the NASA Science Mission Directorate, Washington. Spirit and its twin, Opportunity, landed on Mars in January 2004 and have operated 20 times longer than their original prime missions."

Landing sites