(From west to east)

• Vesta is in the constellation of Sagittarius.
• Pallas is in the constellation of Aquarius.
• Hygiea is at opposition on the 3rd in the constellation of Pisces.
• Victoria is at opposition on the 8th in the constellation of Pisces.
• Egeria is at opposition on the 12th in the constellation of Cetus.
• Flora is in the constellation of Taurus.
• Eunomia is in the constellation of Gemini.
• Information about the Minor Planets can be found at the Minor Planet Observer website.

"With a slight tweak of its trajectory this week, New Horizons is headed toward the heart of the distant Pluto system.

Starting at 4:04 p.m. EDT on Sept. 25, New Horizons fired its thrusters for 15 minutes and 37 seconds, using less than a kilogram of fuel to change its velocity by 2.37 meters per second, or just more than 5 miles per hour. Monitored from the New Horizons Mission Operations Center at the Johns Hopkins Applied Physics Laboratory (APL) in Laurel, Md., the maneuver was only the fourth trajectory correction for the spacecraft since launch in January 2006, and the first since it sped through the Jupiter system last February. The spacecraft was nearly 727 million miles (1.16 billion kilometers) from Earth during the maneuver Ð just about halfway between the orbits of Jupiter and Saturn."

"CAPE CANAVERAL, Fla. - NASA's Dawn spacecraft is on its way to study a pair of asteroids after lifting off Thursday from the Cape Canaveral Air Force Station at 7:34 a.m. EDT (4:34 a.m. PDT).

Mission controllers at NASA's Jet Propulsion Laboratory, Pasadena, Calif., received telemetry on schedule at 9:44 a.m. EDT (6:44 a.m. PDT) indicating Dawn had achieved proper orientation in space and its massive solar array was generating power from the sun.

"Dawn has risen, and the spacecraft is healthy," said the mission's project manager Keyur Patel of JPL. "About this time tomorrow [Friday morning], we will have passed the moon's orbit."

During the next 80 days, spacecraft controllers will test and calibrate the myriad of spacecraft systems and subsystems, ensuring Dawn is ready for the long journey ahead.

"Dawn will travel back in time by probing deep into the asteroid belt," said Dawn Principal Investigator Christopher Russell, University of California, Los Angeles. "This is a moment the space science community has been waiting for since interplanetary spaceflight became possible."

Dawn's 4.8-billion-kilometer (3-billion-mile) odyssey includes exploration of asteroid Vesta in 2011 and the dwarf planet Ceres in 2015. These two icons of the asteroid belt have been witness to much of our solar system's history. By using Dawn's instruments to study both asteroids, scientists more accurately can compare and contrast the two. Dawn's science instrument suite will measure elemental and mineral composition, shape, surface topography, and tectonic history, and will also seek water-bearing minerals. In addition, the Dawn spacecraft and how it orbits Vesta and Ceres will be used to measure the celestial bodies' masses and gravity fields."

• 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.

"NASA's Mars Odyssey spacecraft has discovered entrances to seven possible caves on the slopes of a Martian volcano. The find is fueling interest in potential underground habitats and sparking searches for caverns elsewhere on the Red Planet.

Very dark, nearly circular features ranging in diameter from about 100 to 250 meters (328 to 820 feet) puzzled researchers who found them in images taken by NASA's Mars Odyssey and Mars Global Surveyor orbiters. Using Mars Odyssey's infrared camera to check the daytime and nighttime temperatures of the circles, scientists concluded that they could be windows into underground spaces.

Evidence that the holes may be openings to cavernous spaces comes from the temperature differences detected from infrared images taken in the afternoon and in the pre-dawn morning. From day to night, temperatures of the holes change only about one-third as much as the change in temperature of surrounding ground surface.

"They are cooler than the surrounding surface in the day and warmer at night," said Glen Cushing of the U.S. Geological Survey's Astrogeology Team and of Northern Arizona University, Flagstaff, Ariz. "Their thermal behavior is not as steady as large caves on Earth that often maintain a fairly constant temperature, but it is consistent with these being deep holes in the ground."

"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/

September 24-28, 2007

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

• Ulysses Patera (Released 24 September 2007)
  
• Arsia Mons (Released 25 September 2007)
  
• Ascraeus Mons (Released 26 September 2007)
  
• Olympus Mons (Released 27 September 2007)
  
• Biblis Patera (Released 28 September 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 Arrives at "Stratigraphic Wonderland" - sol 1321-1328, September 27, 2007

"Spirit completed the rover's longest 5-wheel drive to date en route to a platy rock surface nicknamed "Texas Chili" in an area scientists are calling a "stratigraphic wonderland." The platy outcrop is at site 3 on top of "Home Plate" and is the focus of in-depth scientific investigation.

Two sols after not receiving a scheduled data transmission, Spirit drove 19.21 meters (63.02 feet) to the rover's current location about 15 meters (49 feet) away from a field of boulders.

Meanwhile, atmospheric dust levels continued to decline. Tau measurements of atmospheric opacity dropped to 1.06 on sol 1327 (Sept. 27, 2007), with a dust factor of 0.48. Spirit has been averaging 350 watt-hours per Martian day (100 watt-hours is the amount of electricity needed to light a 100-watt bulb for one hour).

Scientific studies of the platy outcrop included alpha-particle X-ray spectrometer measurements both before and after brushing the surface, analysis with the Mšssbauer spectrometer, and acquisition of microscopic images as well as a 360-degree panorama."

Opportunity Status: 'Shaking' Off the Dust and Getting Back to Work - sol 1274-1281, Sep 20, 2007

"The skies continue to clear over the Opportunity site, and the dust is falling from both the sky and the rover. The last week was dedicated to evaluating the payload and assessing dust accumulation on the instruments. Fortunately, the solar array energy has improved to over 350 Watt-hours for the last four sols. This has given the vehicle enough power to support two alpha particle X-ray spectrometer integrations and two Mars Express UHF overflights.

The team began a campaign to recalibrate the panoramic camera tau observations used to measure the level of atmospheric opacity. The recalibration sequences are designed to run at various times of day to get the sun at different angles in the sky. Each sequence has custom exposure durations and color filters tailored to the intended time of execution.

As the team saw last week, the instruments on the robotic arm turret collected a substantial amount of dust during the storm. There are two main concerns: dust inside the alpha particle X-ray spectrometer and dust under the microscopic imager dust cover. On Spirit, dust managed to somehow find its way under the microscopic imager dust cover, so engineers are handling the dust-covered turret on Opportunity with care.

Twice in six sols, the team used the front hazard avoidance camera (and the panoramic and navigation cameras) to image the microscopic imager with the dust cover closed. There were two drives between each set of imaging and there is noticeable cleaning between the two. The first of several sky flats images taken with the microscopic imager (dust cover closed) came down today. Preliminary analysis indicates little to no dust on the lens or dust cover. Next week, the team will determine if it is safe to open the dust cover and take images to see if any dust is on the lens itself.

The first of two alpha particle X-ray spectrometer integrations was received on the ground today and the initial analysis shows little to no dust contamination. Argon peaks are just as large as before, but additional integrations are necessary to complete the analysis. In the meantime, the team modified the robotic arm ready position to face the alpha particle X-ray spectrometer in towards the vehicle's warm electronics box. The hope is that this will prevent any dust from collecting inside."

Landing sites