(From west to east)

• Iris is in the constellation of Gemini.

• Parthenope is in the constellation of Virgo.

• Juno is in the constellation of Virgo.

• Vesta is at opposition on the 30th in the constellation of Ophiuchus.

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

"Cassini's radar eyes will image additional regions near Titan's north pole during an April 26, 2007, flyby. The instrument will image the area slightly north of an area nicknamed the "black sea." The radar coverage will cross over four previous radar swaths and begin to fill in more of the gaps in the coverage of Titan's north pole. On this flyby, Cassini's infrared spectrometer will see the lit and dark sides of Titan, looking for hot spots and lightning. The imaging cameras will do global mapping and full-disk mosaics."

Cassini Imaging Team

"The New Horizons Multicolor Visible Imaging Camera (MVIC) took this image of Jupiter's volcanic moon Io at 04:30 Universal Time on February 28, 2007, about one hour before New Horizons' closest approach to Jupiter, from a range of 2.7 million kilometers (1.7 million miles). Part of the Ralph imaging instrument, MVIC is designed for the very faint solar illumination at Pluto, and is too sensitive to image the brightly lit daysides of Jupiter's moons. Io's dayside is therefore completely overexposed in this image, and appears white and featureless. However, the Jupiter-lit nightside of Io and the giant plume from the Tvashtar volcano are well exposed, and the versions of the image shown here have been processed to bring out each of these features."

"WASHINGTON - After studying Mars four times as long as originally planned, NASA's Mars Global Surveyor orbiter appears to have succumbed to battery failure caused by a complex sequence of events involving the onboard computer memory and ground commands.

The causes were released today in a preliminary report by an internal review board. The board was formed to look more in-depth into why NASA's Mars Global Surveyor went silent in November 2006 and recommend any processes or procedures that could increase safety for other spacecraft.

Mars Global Surveyor last communicated with Earth on Nov. 2, 2006. Within 11 hours, depleted batteries likely left the spacecraft unable to control its orientation.

"The loss of the spacecraft was the result of a series of events linked to a computer error made five months before the likely battery failure," said board Chairperson Dolly Perkins, deputy director-technical of NASA Goddard Space Flight Center, Greenbelt, Md."

• All of the Mars Global Surveyor images are archived here.

Information about how to submit requests is online at the new Mars Orbiter Camera Target Request Site, at http://www.msss.com/plan/intro"

Newly-released MOC images can be seen in the MOC Gallery, a website maintained by Malin Space Science Systems, the company that built and operates MOC for the Jet Propulsion Laboratory and NASA.

"Engineers for NASA's Mars Odyssey mission are examining data from the orbiter to determine whether onboard backup systems never used by the 6-year-old spacecraft could still be available if needed.

Odyssey reported last week that a power processing component of the backup, or "B-side," systems had stopped working. The component, the high-efficiency power supply, has a twin that is continuing to serve the "A-side" hardware, which is operating normally. Odyssey has stayed on its A-side systems, including the A-side flight computer, since launch on April 7, 2001. However, the A-side power supply cannot serve most systems on the B-side, including the backup B-side computer. If engineers do not determine a way to restore the B-side power supply, most of the backup hardware would not be available, if it were ever needed."

"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/

April 23-27, 2007

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

• Texture Changes (Released 23 April 2007)
  
• Kaiser Crater (Released 24 April 2007)
  
• Frosty Dunes (Released 25 April 2007)
  
• Sirenum Fossae (Released 26 April 2007)
  
• Crater Dunes (Released 27 April 2007)
  
• 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 Continues Studies En Route to 'Home Plate' - sol 1159-1163, April 13, 2007

"Spirit is healthy and has completed a campaign of scientific studies of a rock outcrop known as "Elizabeth Mahon," on the edge of "Home Plate." Spirit is now en route to another outcrop nicknamed "Madeline English." The route involves driving backward, turning around, backing up, parking in parallel between two sizable rocks flanking the target, pivoting clockwise on the stuck right front wheel, and finally "crabbing" forward to the target. Spirit performs crabbing by steering the two rear wheels toward the stuck right front wheel, thus opposing resistance from the right front wheel and keeping yawing (swinging from side to side) to a minimum.

Spirit executed the "parallel parking" portion of the trip on the rover's 1,162nd Martian day, or sol, of exploration (April 10, 2007). The final "crab" portion was planned for sol 1164 (April 12, 2007). After the investigation of Madeline English, plans called for the rover to head north to one of several possible "on-ramps" for driving onto Home Plate."

Opportunity Status: Imaging 'Alicante' - sol 1145-1151, April 24, 2007

"Over the last week, Opportunity investigated the second of two "dark streak" soil targets named "Alicante." The sol 1145 Mšssbauer touch sequence that was commanded did not make contact with the soil because of a minor targeting discrepancy. Since the Mšssbauer touch is used as a reference point for determining where to start taking the microscopic images, the lack of contact caused the images taken sol 1145 to be out of focus. As a result, the team decided to stay another two sols and reacquire the in-situ observations on Alicante. Now, Opportunity is headed southeast towards "Tierra del Fuego" to begin another remote sensing campaign."

Landing sites

"NASA's Mars Reconnaissance Orbiter put itself into safe mode -- a precautionary status with minimized activities -- on March 14. It remained healthy and in communication with Earth, but with no science observations, while the flight team examined engineering data. On March 20, the team brought the spacecraft back out of safe mode.

Science instruments were powered up March 21 and are resuming normal science operations today, March 22.

When it went into safe mode, the spacecraft switched, for the first time in the mission, to a backup ("B") duplicate flight computer on board. Diagnosis of the "A" computer has not yet revealed what caused the switch to the B side."