(From west to east)

• Eunomia is in the constellation of Gemini.
• Hebe is in the constellation of Cancer.
• Iris, Astraea and Daphne are in the constellation of Virgo.
• Pallas is in conjunction with the Sun on the 29th.
• Information about the Minor Planets can be found at the Minor Planet Observer website.

"The Cassini spacecraft captures Janus in the foreground, with Dione in the distance beyond.

The image was taken two hours after Hiding Dione, in which Cassini imaged Dione beyond the rings.

Janus is 181 kilometers (113 miles) across. Dione is 1,126 kilometers (700 miles) across. North on the moons is up.

The image was taken in visible light with the Cassini spacecraft narrow-angle camera on Jan. 17, 2008. The view was obtained at a distance of approximately 1.2 million kilometers (766,000 miles) from Janus and 1.6 million kilometers (970,000 miles) from Dione. Image scale is 7 kilometers (4 miles) per pixel on Janus and 9 kilometers (6 miles) per pixel on Dione."

Cassini Imaging Team

"A year ago, New Horizons was flying through the heart of the Jupiter system, gradually picking up speed and systematically gathering spectacular data on the solar systemÕs largest planet and its closest moons. The results of that spectacular flyby have since been featured on thousands of electronic and printed pages, including a special issue of the journal Science in October 2007.

New Horizons scientists recently took a new look at one of the more memorable images from the Jupiter collection: that of the erupting volcano Tvashtar on the moon Io. Taken through two of the four filters in the sensitive Multispectral Visible Imaging Camera, the picture shows the reddish colors of the plume deposits surrounding the base of the volcano - a view we hadnÕt seen in earlier pictures. Check it out in the New Horizons gallery."

"NASA's Dawn spacecraft has successfully completed the initial checkout phase of the mission and begun its interplanetary cruise phase, which is highlighted by nearly continuous thrusting of its ion propulsion system. Dawn is on a 8-year, 3-billion mile journey to asteroid Vesta and dwarf planet Ceres."

"As MESSENGER sped by Mercury on January 14, 2008, the Narrow Angle Camera (NAC) of the Mercury Dual Imaging System (MDIS) captured this image, which includes the edge of the planet against the blackness of space. Much of the foreground shows a portion of Caloris basin, one of the largest impact basins in the solar system. The two large craters near the bottom of this image can be identified on the northwestern floor of the basin on the mosaicked image of Caloris released at MESSENGERÕs NASA press conference on January 30, 2008. The large crater in the bottom middle of this image has a diameter of about 70 kilometers (40 miles)."

"As expected, scientists at JPL's Near-Earth Object Office have further refined the trajectory estimate for asteroid 2007 WD5 and ruled out any possibility of a Mars impact on Jan. 30. The latest trajectory plot of the asteroid was made possible by adding to previously obtained data some new data from a round of observations acquired by three observatories on the evenings of Jan. 5 through 8. Based on this latest analysis, the odds for the asteroid impacting Mars on Jan. 30 are 0.0 percent. The latest observations come from the German-Spanish Astronomical Center, Calar Alto, Spain; the Multi-Mirror Telescope, Mt. Hopkins, Ariz.; and the University of Hawaii telescope, Mauna Kea, Hawaii."

"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 http://themis.asu.edu."

Mars Odyssey THEMIS Images
Thermal Emission Imaging System (THEMIS) website: http://themis.asu.edu/

February 18-22, 2008

The following new images from the Mars Odyssey spacecraft are now available:

• Not Round (Released 18 February 2008)
  
• Padus Vallis (Released 19 February 2008)
  
• Iberus Vallis (Released 20 February 2008)
  
• Patapsco Vallis (Released 21 February 2008)
  
• Windstreaks (Released 22 February 2008)
  
• All of the THEMIS images are archived here.

The Odyssey data are available through a new online access system established by the Planetary Data System at: http://starbrite.jpl.nasa.gov/pds/"

Spirit Status: Spirit Inches Downward - sol 1457-1463, February 13, 2008

"Spirit is tiptoeing ever so carefully down the north edge of the elevated volcanic plateau known as "Home Plate." Having completed a 4-centimeter (1.6-inch) drive on sol 1463 (Feb. 13, 2008), the rover's current northerly tilt is 27.1 degrees. Spirit's handlers plan to have the rover drive another 4 centimeters on sol 1464 (Feb. 14, 2008).

They expect Spirit to be at the rover's final winter perch by the end of next week, following a few more 4-centimeter drives. Given recent progress, Spirit may achieve a northerly, Sun-facing tilt of 30 degrees, higher than originally anticipated. Spirit remains healthy."

Opportunity Status: Opportunity Proceeds with Caution on Sandy Slopes - sol 1437-1443, Feb 14, 2008

"After recovering from a stall in Joint 1, which controls the compass orientation of the shoulder on the rover's robotic arm, Opportunity is proceeding carefully to its next target, an exposure of layered rocks known as "Gilbert."

Opportunity ran the usual diagnostic tests for this sort of fault, which occurred while the rover was studying a rock target known as "Buckland," and successfully placed the Mössbauer spectrometer on the target on Sol 1437 (Feb. 8, 2008). On Sol 1438 (Feb. 9, 2008), the rover's handlers decided to relinquish further scientific studies of the target and proceed instead with a drive toward Gilbert. As this meant the rover would wander into new terrain, the team created a series of steps to allow Opportunity to characterize the surroundings along the way.

One of these steps involved placing the front two wheels on an area of soil to leave a scuff on the surface and backing up to take images of the exposed area. On Sol 1438, however, prior to reaching the intended soil area, Opportunity aborted the drive. The rover completed the second planned "scuffing" on Sol 1441 (Feb. 12, 2008). This time the scuff was successful, though it revealed an interesting surprise -- Opportunity's right front wheel dug in much more than the rover's handlers had expected, highlighting the need to proceed cautiously toward Gilbert.

Because Opportunity was unable to relay all of the diagnostic data to Earth at one time because the volume of data was more than could be accommodated, the rover's handlers decided that the prudent course of action was to wait one planning cycle before having Opportunity proceed with the drive. On Sol 1443 (Feb. 14, 2008), Opportunity completed a diagnostic examination of the grind bit on the rock abrasion tool and collected a mosaic of microscopic images of a rock target dubbed "Lyell Exeter," commemorating the college attended by geologist Sir Charles Lyell in the early 1800s, as well as compositional data using the alpha-particle X-ray spectrometer.

Opportunity is healthy and all subsystems are performing as expected. The latest available measurements on Sol 1443 showed a power level of 469 watt-hours (100 watt-hours is the amount of energy needed to light a 100-watt bulb for 1 hour). Plans for the coming weekend called for the rover to proceed with the first of a two-step drive toward Gilbert."

Landing sites