* Astronomy

SPIRIT UPDATE: Spirit Studies Layers of Volcanic Rock - sol 977-981, October 13, 2006:

Spirit is healthy and continues to make progress on a winter science campaign of experiments.
In parallel with normal planning, a special team has been developing plans to be executed during solar conjunction, when the sun obscures the line of sight between Earth and Mars and severely limits radio communication. Rover handlers will upload the plans to be executed by Spirit during solar conjunction prior to the beginning of conjunction. This year's solar conjunction period begins on the rover's 991st Martian day, or sol, (Oct. 16, 2006) and ends on sol 1005 (Oct. 30, 2006). Planning for future activities on sols 1006 and 1007 (Oct. 31 to Nov. 1, 2006) will resume Oct. 30.
Spirit continued to produce atmospheric profiles of dust, temperature at different heights, ice, and water vapour, as well as surface and sub-surface temperatures using the miniature thermal emission spectrometer. Plans also called for a scan of the sky for clouds, which, if found, could be incorporated into a multi-frame movie for observing cloud movement.
Spirit acquired super-resolution panoramic camera images of volcanic outcrops called "Marambio," "Jubany," and "Mitcheltree Ridge" on sols 979 and 981 (Oct. 4 and Oct. 6, 2006). The outcrops consist of basalt, a dense, dark rock that hardens from lava and often has a glassy appearance. These basalts were also vesicular, meaning they are porous because there were gas bubbles in the lava when it solidified.
The purpose of the super-resolution imaging campaign is to identify and map characteristics of the local geology. In particular, scientists hope to determine the relative stratigraphy of Mitcheltree Ridge, "Low Ridge," and the raised, circular plateau known as "Home Plate." Stratigraphy is the study of rock layers.

Spirit's solar energy levels continued to rise, ending the week at around 300 watt-hours.

Sol-by-sol summary:

Sol 977 (Oct. 2, 2006): Spirit measured atmospheric opacity using the panoramic camera, surveyed the sky and ground with the miniature thermal emission spectrometer, used the Mössbauer spectrometer to analyse dust collected by the filter magnets, acquired panoramic camera images of the work volume accessible by the robotic arm, and collected images of the rover's tracks with the miniature thermal emission spectrometer.

Sol 978: Spirit measured atmospheric opacity using the panoramic camera, surveyed the sky and ground with the miniature thermal emission spectrometer, and collected thermal data from targets known as "Casey Station" and "Sobral." The rover acquired super-resolution images of volcanic rock outcrops called Marambio and Jubany and measured morning sky brightness in the west with the panoramic camera.

Sol 979: Spirit measured atmospheric dust opacity using the panoramic camera, surveyed the sky and ground with the miniature thermal emission spectrometer, and restarted integration of data from the Mössbauer spectrometer's inspection of dust on the filter magnets. In addition, Spirit acquired morning images of the dune field known as "El Dorado" as well as images of the Martian horizon using the panoramic camera, measured morning sky brightness in the west with the panoramic camera, and scanned the sky for clouds using the navigation camera.

Sol 980: Spirit measured atmospheric dust opacity using the panoramic camera, surveyed the sky and ground with the miniature thermal emission spectrometer, surveyed the sky with the panoramic camera, and acquired super-resolution images of Mitcheltree Ridge with the panoramic camera.

Sol 981 (Oct. 6, 2006): Spirit measured atmospheric dust opacity using the panoramic camera, surveyed the sky and ground with the miniature thermal emission spectrometer, restarted integration of data from the filter magnets with the Mössbauer spectrometer, and acquired super-resolution panoramic camera images of the soil target known as "Tyrone."

Odometry:
As of sol 981 (Oct. 6, 2006), Spirit's total odometry remained at 6,876.18 metres.

SPIRIT UPDATE: Solar Power Is on the Rise as Spirit 'Follows the Water' - sol 970-976, September 29, 2006:
Solar power levels on Spirit are slowly beginning to rise again following a winter low of 275 watt-hours on Martian day, or sol, 933 (Aug. 18, 2006). This week, the rover's power levels rose to about 296 watt-hours.
Spirit spent much of the week analysing atmospheric dust attracted to magnets on the spacecraft. The rover identifies iron minerals in the dust using the Mössbauer spectrometer. One of the two magnets, the filter magnet, is weaker than the capture magnet, allowing scientists to separate mineral grains that have the highest magnetic susceptibility, particularly minerals that contain iron.
During the week, Spirit studied rock targets known as "Juan Carlos," "Gueslaga," and "Tor" using the miniature thermal emission spectrometer. Juan Carlos and Tor are vesicular rocks filled with tiny holes that formed during the cooling of a froth of magma and gas. Scientists hope to determine whether these rocks are similar to or different from nearby smooth-textured volcanic rocks known as basalts. Gueslaga, meanwhile, is an entirely different kind of rock known as an "exotic," meaning it came from somewhere else and may have been emplaced during an impact event.
Spirit continued to make scientific observations of the soil target known as "Tyrone." Tyrone is a patch of bright material, white and yellow in color, that is possibly analogous to salty soils examined earlier in the mission known as "Arad" and "Paso Robles." Spirit's dragging right front wheel churned up the bright material on the rover's 784th sol of exploration of Mars (March 18, 2006). Some science team members have speculated that some component in this material is hydrated. If moisture enters or leaves the material, the miniature thermal emission spectrometer would be able to detect it. Scientists are also monitoring the soil with the rover's panoramic camera for any colour changes, because variability in water content could affect the colour. These observations are ongoing to account for seasonal variability.
The rover continues to operate successfully with the new flight software package.

Sol-by-sol summaries:

Sol 970 (Sept. 25, 2006): Spirit measured atmospheric opacity using the panoramic camera, surveyed the sky and ground with the miniature thermal emission spectrometer, analysed dust on the filter magnet with the Mössbauer spectrometer, acquired morning images of the spacecraft deck with the panoramic camera, and scanned the sky for clouds with the navigation camera.

Sol 971: Spirit measured atmospheric opacity using the panoramic camera, surveyed the sky and ground with the miniature thermal emission spectrometer, collected data from the rock target known as Juan Carlos, and surveyed the horizon using the panoramic camera.

Sol 972: Spirit measured atmospheric opacity using the panoramic camera, surveyed the sky and ground with the miniature thermal emission spectrometer, restarted integration of data from the filter magnets with the Mössbauer spectrometer, acquired panoramic camera images of the work volume accessible by the robotic arm, and measured morning sky brightness in the west with the panoramic camera.

Sol 973: Spirit measured atmospheric opacity using the panoramic camera, surveyed the sky and ground with the miniature thermal emission spectrometer, studied the rock targets Gueslaga and Tor using the miniature thermal emission spectrometer, and used the panoramic camera to take images of rover tracks and measure morning sky brightness in the west.

Sol 974: Plans called for Spirit to measure atmospheric opacity using the panoramic camera, survey the sky and ground with the miniature thermal emission spectrometer, restart integration of data from the filter magnets with the Mössbauer spectrometer, survey the sky and ground with the miniature thermal emission spectrometer, scan the sky for clouds, measure morning sky brightness, and take a morning measurement of dust on the panoramic camera mast assembly with the miniature thermal emission spectrometer.

Sol 975: Plans called for Spirit to measure atmospheric opacity using the panoramic camera, survey the sky and ground with the miniature thermal emission spectrometer, and acquire morning images of the rover's tracks with all 13 filters of the panoramic camera.

Sol 976 (Oct. 1, 2006): Plans called for Spirit to measure atmospheric opacity using the panoramic camera, survey the sky and ground using the miniature thermal emission spectrometer, continue analysis of dust on the filter magnets with the Mössbauer spectrometer, and complete a morning sky survey with the panoramic camera.

Odometry:
As of sol 973 (Sept. 28, 2006), Spirit's total odometry remained at 6,876.18 metres.

SPIRIT UPDATE: The Martian Sun Also Rises as Winter Retreats - sol 957-963, September 14, 2006:

Spirit is beginning to see an upward trend in electrical power as winter slowly recedes and the sun ascends higher in the sky each day. Electrical power from the rover's solar array rose to 287 watt-hours on the rover's 958th Martian day, or sol (Sept. 12, 2006) of exploration, compared with 277 watt-hours on sol 944 (Aug. 29, 2006). One hundred watt-hours is the amount of electricity needed to light one 100-watt bulb for one hour.
During the past week, Spirit conducted 10 hours of analysis of the elemental composition of dust on the rover's magnets using the alpha particle X-ray spectrometer. Spirit also finished taking images of the spacecraft deck.

Sol-by-sol summaries:

Sol 957 (Sept. 11, 2006): Spirit continues to complete the same set of observations each sol in parallel with engineering activities such as data management. The engineering block of activities includes monitoring atmospheric dust with the panoramic camera, and surveying the sky and ground with the miniature thermal emission spectrometer. On this particular sol, Spirit demonstrated additional multi-tasking abilities by acquiring data on a rock target known as "Vostok" using the miniature thermal emission spectrometer while transmitting data to the Odyssey spacecraft as it passed overhead.

Sol 958: Spirit acquired part 13 of the 15-part image mosaic of the spacecraft deck with the panoramic camera. Spirit spent about five hours acquiring data on the elemental composition of dust on the rover's filter magnets using the alpha particle X-ray spectrometer.

Sol 959: Spirit acquired panoramic camera images of a soil target consisting of bright material in the rover's tracks known as "Tyrone."

Sol 960: Plans called for Spirit to continue to acquire panoramic images of the rover deck, restart the alpha particle X-ray spectrometer following the overhead pass of the Odyssey spacecraft, and spend 4 hours and 50 minutes collecting elemental data of dust on the filter magnets. Plans also called for a morning measurement of sky brightness in the west with the panoramic camera (known as a pancam skyspot), a search for clouds using the navigation camera, a horizon survey with the panoramic camera, imaging of the "El Dorado" dune field with the panoramic camera, and imaging of ripples with the rear hazard avoidance camera.

Sol 961: Plans called for Spirit to acquire data from a target known as "Macquarie" with the miniature thermal emission spectrometer, acquire data from the calibration target with the miniature thermal emission spectrometer, and search for clouds with the navigation camera.

Sol 962: Plans called for Spirit to acquire the last segment of the 15-part panoramic mosaic of the spacecraft deck and conduct a 4-hour and 35-minute alpha particle X-ray spectrometer analysis of the filter magnets. Plans also called for Spirit to acquire sky images with the panoramic camera and validate measurements of complete darkness by the panoramic camera.

Sol 963 (Sept. 18, 2006): Plans called for Spirit to acquire images of the rover's tracks with the navigation camera, take microscopic images of the filter and capture magnets, and place the alpha particle X-ray spectrometer on the capture magnet. Plans also called for the rover to acquire hazard avoidance camera images of the work volume reached by the rover's robotic arm, monitor dust on the panoramic camera mast assembly, survey the horizon with the panoramic camera, and search for morning clouds with the navigation camera.

Odometry:
As of sol 958 (Sept. 12, 2006), Spirit's total odometry remained at 6,876.18 metres.

SPIRIT UPDATE: Spirit Monitors Dust and Searches for Clouds - sol 950-956, September 08, 2006:

Spirit is healthy and continues to make progress on the rover's winter science campaign. During the past week, Spirit continued filling in sections of the rover's deck as part of the "Deck Pan" mosaic of panoramic images.
Electrical power from the rover's solar array has continued to hold steady at approximately 280 watt-hours per sol.

Sol-by-sol summaries:

Sol 950 (Sept. 4, 2006): Spirit collected images of the rover deck with the panoramic camera, checked the atmosphere for opacity caused by dust, and scanned the sky and ground with the miniature thermal emission spectrometer.

Sol 951: Spirit collected images of the rover deck with the panoramic camera, checked the atmosphere for opacity caused by dust, and scanned the sky and ground with the miniature thermal emission spectrometer.

Sol 952: Spirit collected images of the rover deck with the panoramic camera, checked the atmosphere for opacity caused by dust, and scanned the sky and ground with the miniature thermal emission spectrometer.

Sol 953: Plans called for Spirit to acquire images of the sun high in the sky and acquire data from rock targets known as "Primero" and "Castilla" using the miniature thermal emission spectrometer. Plans also included checking the atmosphere for opacity caused by dust and scanning the sky and ground with the miniature thermal emission spectrometer.

Sol 954: Plans called for Spirit to acquire panoramic camera images of the capture and filter magnets (two dust-collecting magnets on the rover deck), search for clouds using the navigation camera, check the atmosphere for opacity caused by dust, and scan the sky and ground with the miniature thermal emission spectrometer.

Sol 955: Plans called for Spirit to acquire images of the rover deck, microscopic images of the capture magnet, and miniature thermal emission spectrometer data on a rock target known as "Signy." The rover was also slated to make daily observations of the sky and ground with the panoramic camera and miniature thermal emission spectrometer.

Sol 956 (Sept. 11, 2006): Plans called for Spirit to collect images of the rover deck with the panoramic camera and microscopic images of the filter magnet, as well as make the usual daily observations of the sky and ground with the panoramic camera and miniature thermal emission spectrometer.

Odometry:
As of sol 952 (Sept. 6, 2006), Spirit's total odometry remained at 6,876.18 metres.