* Astronomy

Image of the homeplate feature taken by the Spirit rover on September 29, 2007 (Sol 1329)


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SPIRIT UPDATE: 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  to the rover's current location about 15 meters  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 Mössbauer spectrometer, and acquisition of microscopic images as well as a 360-degree panorama.

Sol-by-sol summary
Spirit began each Martian day by measuring atmospheric dust with the panoramic camera, checking for drift (changes with time) in the miniature thermal emission spectrometer, and surveying the sky and ground with the miniature thermal emission spectrometer. In addition to those tasks, Spirit completed the following activities:

Sol 1321 (Sept. 21, 2007): Rather than completing the drive toward Home Plate as intended, Spirit executed the previous sol's activities. As a result of an internal failure in a station at the Deep Space Network in Madrid, rover handlers were unable to transmit instructions to Spirit via the rover's high-gain antenna.

Sol 1322: Spirit spent the first sol of a three-sol weekend collecting remote science data, including panoramic camera images of a target known as "Ambrosia" and miniature thermal emission spectrometer measurements of Ambrosia as well as targets known as "Bisque" and "Cobbler."

Sol 1323: Spirit acquired panoramic camera images of Bisque and Cobbler before completing the 19.21-meter  drive to site 3 on Home Plate. The rover took images with the hazard avoidance cameras before and after ending the drive and acquired post-drive image mosaics with the navigation and panoramic cameras.

Sol 1324: Spirit acquired near-field panoramic camera images and spent the third sol of a three-sol weekend collecting untargeted remote sensing data. Observations included movie frames in search of dust devils with the navigation camera and a systematic foreground survey with the miniature thermal emission spectrometer.

Sol 1325: Spirit surveyed rock clasts with the panoramic camera and scanned the sky for clouds with the navigation camera. The rover began work on a 360-degree panorama as well as scientific studies of Texas Chili. Spirit acquired navigation camera images in support of observations with the miniature thermal emission spectrometer, completed a full-colour, systematic, foreground survey using all 13 filters of the panoramic camera, and acquired a mosaic of images of site 3 with the panoramic camera. Spirit studied targets known as "Hardy Point," "Harmony Point," and "Ohridiski" with the miniature thermal emission spectrometer. The rover unstowed the robotic arm and placed the alpha-particle X-ray spectrometer on Texas Chili.

Sol 1326: In the morning, Spirit monitored dust on the rover mast. Later, the rover acquired more panoramic camera images of site 3, brushed the surface of Texas Chili with the rock abrasion tool, and acquired images of the microscopic imager with the front hazard avoidance camera to monitor dust accumulation. Spirit placed the alpha-particle X-ray spectrometer back on the target and collected data for about 18 hours.

Sol 1327: In the morning, Spirit received communications via the European Space Agency's Mars Express orbiter. The rover acquired more panoramic camera images of site 3, switched tools from the alpha-particle X-ray spectrometer to the Mössbauer spectrometer, and collected Mössbauer data from Texas Chili for about 21 hours.

Sol 1328 (Sept. 28, 2007): Spirit took thumbnail images of the sky with the panoramic camera, re-started the Mössbauer spectrometer, and collected Mössbauer data from Texas Chili for about 25 hours. The rover took more panoramic camera images of site 3 and was slated to continue doing so the following morning.

Odometry:
As of sol 1327 (Sept. 27, 2007), Spirit's total odometry was 7,234.09 meters.

SPIRIT UPDATE: Spirit Explores Top of "Home Plate" - sol 1309-1314, September 18, 2007:

After spending some time getting used to the terrain on top of "Home Plate," Spirit began driving across the top of the elevated plateau, en route to taking more images and examining a possible fracture in the bedrock.
On the rover's 1,310th Martian day, or sol, of exploration (Sept. 9, 2007), Spirit completed a drive characterisation to determine how the rover responded on Home Plate terrain. After passing that test, Spirit proceeded toward a destination known as "Site 2." Plans called for the rover to acquire the second portion of a long-baseline, stereo view of "Husband Hill" and study the potential fracture. In addition, Spirit was slated to collect remote sensing data looking to the west, southwest, and south in search of possible drive paths as well as geological information.

Sol-by-sol summary
In addition to measuring atmospheric opacity with the panoramic camera, surveying the sky and ground with the miniature thermal emission spectrometer, and checking for drift (changes with time) in the miniature thermal emission spectrometer, Spirit completed the following activities:

Sol 1309 (Sept. 8, 2007): Spirit examined targets known as "Gumbo," "Goulash," "Stew," and "Pudding" with the miniature thermal emission spectrometer. Spirit took wide-range atmospheric dust measurements using the panoramic camera and then, after the evening pass of the Odyssey orbiter, recalibrated the dust measurements of the panoramic camera.

Sol 1310: Spirit acquired panoramic camera images of Gumbo and Goulash. The rover turned in place to characterise the drive toward Site 2 and started driving in that direction. Spirit took images with the hazard avoidance cameras just before and after completing the drive as well as post-drive images with the panoramic camera.

Sol 1311: Spirit surveyed the horizon with the panoramic camera.

Sol 1312: Spirit monitored dust accumulation on the rover's mast with the panoramic camera and continued driving. The rover acquired images with the hazard avoidance cameras before and after completing the drive and acquired post-drive images with the panoramic and navigation cameras. Spirit acquired a rearward-looking mosaic of navigation camera images, surveyed the external calibration target with the miniature thermal emission spectrometer, and completed a systematic ground survey using all 13 filters of the panoramic camera.

Sol 1313: Spirit surveyed the horizon with the panoramic camera.

Sol 1314 (Sept. 13, 2007): Spirit acquired full-colour views, using all 13 filters of the panoramic camera, of the fracture on Home Plate. The rover acquired forward-looking images with the panoramic camera and acquired data from targets dubbed "Tapioca," "Bouillabaisse," and "Dumplings" with the miniature thermal emission spectrometer. Spirit acquired wide-range measurements of atmospheric dust with the panoramic camera and measured atmospheric argon with the alpha-particle X-ray spectrometer. After the overpass of the Odyssey orbiter, Spirit recalibrated dust measurements with the panoramic camera. The following morning, the rover was to acquire panoramic camera images of Dumplings and complete a survey of rock clasts.

Odometry:
As of sol 1312 (Sept. 11, 2007), Spirit's total odometry was 7,206 metres.

SPIRIT UPDATE: Spirit Finally Arrives at Home Plate! - sol 1303-1308, September 10, 2007:

After remaining beyond the margins of Home Plate ever since exiting its northeast edge on Sol 774 (March 7, 2006) to survive the first winter on Mars, Spirit finally climbed on top of the elevated, circular plateau that scientists believe is volcanic in origin.

Before completing the final drive, however, Spirit returned to the soil patch nicknamed "Gertude Weise," made of nearly pure silicon dioxide, to acquire data that will help scientists characterize how much dust has accumulated on the instrument optics of the miniature thermal emission spectrometer.
The miniature thermal emission spectrometer is inside the boxy body of the rover, below the mast. Mirrors inside the mast allow the instrument to see outside. The rover has been using the spectrometer to measure changes in the atmosphere during the recent dust storm on Mars. When the instrument is not in use, a cover protects it from dust floating in the atmosphere but it isn't air-tight.
After completing measurements of Gertrude Weise, Spirit was once again on the move. The rover attempted to "thread the needle" by driving between two rocks on sol 1304 (Sept. 3, 2007) and place the rear two wheels on the top of Home Plate (Spirit must drive backward to drag the frozen right front wheel).
As it turned out, the drive was more difficult than anticipated. On the first attempt, Spirit immediately stopped driving when the rover's wheels entered an area designated as a keepout zone. This occurred as the rover was attempting to compensate for drag from the right front wheel by turning slightly in the opposite direction. Normally, the dragging wheel causes Spirit to yaw counter-clockwise (as viewed from above), but the amount of counter-clockwise spin depends on the amount of drag encountered by the right front wheel. Rocky surfaces cause less drag than soil. In this case, the drag was less than anticipated.
On sol 1306 (Sept. 5, 2007), Spirit tried again and executed the drive flawlessly! Now that the rover's two rear wheels are on top of the eastern edge of Home Plate, Spirit is in position to explore the top of the elevated plateau along its eastern and southern edges. The next planned stop is a few meters away in an area known as "Site 2," located midway along the eastern scarp of Home Plate east scarp and several meters to the west of the scarp. (If you compared the roughly circular shape of the top of Home Plate to a clock, Site 2 would be at 3:30.)
After that, scientists plan to have Spirit proceed to "Site 3," at the southern end of Home Plate (6 o'clock position) and "Site 4," at the southwestern corner of Home Plate (7:30 position).
By collecting data at all these sites, scientists hope to interpret the geologic structure of Home Plate, determine how the rock chemistry changes from one side to the other, and elucidate a fracture that crosses the plateau from west to east. Along the way, the rover will take images of the south face of "Husband Hill" to the north and outcrops known as "Goddard" and "von Braun" to the south.
In recent months, rover handlers have been naming local features and targets around Home Plate for deceased members of the All-American Girls Professional Baseball League. Because Home Plate is bowl-shaped, scientists have decided to name features on top of Home Plate after things served in bowls. Stay tuned for upcoming yummy descriptions!

Sol-by-sol summary:
In addition to measuring atmospheric opacity with the panoramic and navigation cameras, surveying the sky and ground with the miniature thermal emission spectrometer, and checking for drift (changes with time) in the miniature thermal emission spectrometer, Spirit completed the following activities:

Sol 1303 (Sept. 2, 2007): Spirit studied a target known as "Gertrude Weise14," the background of the target, a soil target labelled "Innocent Bystander Disturbed Area 1," and a target known as "Mary Dailey3" as well as its background with the miniature thermal emission spectrometer. Spirit recalibrated the panoramic camera and acquired miniature thermal emission spectrometer data on a target dubbed "Joanne Winter2."

Sol 1304: Spirit acquired full-colour images of the disturbed soil area using all 13 filters of the panoramic camera before driving 2.42 meters toward Home Plate. The rover took images just before and after completing the drive with the hazard avoidance cameras as well as post-drive images with the navigation and panoramic cameras.

Sol 1305: Spirit surveyed the rover's external calibration target using the miniature thermal emission spectrometer and acquired movie frames in search of dust devils using the navigation camera. The rover recalibrated the panoramic camera.

Sol 1306: Before beginning the sol's drive, Spirit acquired full-colour images of the rover's external calibration target as well as the disturbed soil area of Innocent Bystander using all 13 filters of the panoramic camera. After completing the 8.21-meter drive, the rover took images of the surrounding terrain with the navigation camera and forward-looking images with the panoramic camera.

Sol 1307: Spirit completed a survey of rock clasts with the panoramic camera and assessed the calibration target with the miniature thermal emission spectrometer.

Sol 1308 (Sept. 7, 2007): Spirit acquired images of dust in the sky with the panoramic camera, calibrated the miniature thermal emission spectrometer, and listed files in the rover's flash memory (a type of rewritable electronic memory that retains information even when power is off). Spirit completed a systematic foreground survey using all 13 filters of the panoramic camera and measured albedo (surface reflectivity) using the panoramic camera. With the miniature thermal emission spectrometer, the rover surveyed a soil target known as "Beef_Chili," a rock target known as "Cajun_Chili," and the external calibration target.

Odometry:
As of sol 1306 (Sept. 5, 2007), Spirit's total odometry was 7,182.49 metres.