MGS is currently "parked" in a so-called science phasing orbit with a period of 11 hours and 38 minutes. The altitude of the closest approach to Mars at the periapse of each orbit is approximately 110 miles. The first aerobraking phase of the mission has been completed. In the current science phasing orbit, the spacecraft does not pass sufficiently deep in the upper martian atmosphere to reduce the orbit period and altitude. The second aerobraking phase of the mission will begin in September, and MGS should achieve its final Mars mapping orbit early next year. The main mapping phase of the mission will begin in March, 1999 and is still expected to have a duration of one full martian year (687 days).
The MGS Radio Science Team conducted its first martian meteorological "campaign" between the end of January and the middle of April this year. Due to a change in MGS operations, the Team was only recently able to process the data from the final few weeks of the campaign. We do not expect to have such a delay during the main MGS mapping mission. All of the data which the Team has acquired are now available to participants in the outreach program. The data were acquired at some northern latitudes and a wide range of southern latitudes, including observations deep in the Hellas and Argyre basins of Mars and in the vicinity of the great Tharsis volcanoes and the tremendous Valles Marineris canyon. The period during which data were acquired at Mars included the northern winter/southern summer solstice.
A map showing the locations of all of the martian meteorological observations may be found in the Late Martian Weather! department of this Web site. If you click on the location of any of the martian weather observations, you will find out the precise location of the measurement, the date on which the measurement was made, the local time on Mars where the measurement was recorded, the surface elevation, and the surface temperature and atmospheric pressure.
Some representative profiles of the temperature and pressure of the martian atmosphere have been posted in the Martian Temperature and Pressure Profiles! area on this site. The profiles contain a wealth of information about the martian atmosphere, and are similar to soundings of our own atmosphere in that they illustrate how temperature and pressure vary with height above the surface. All of the data which the MGS Radio Science Team has made available to participants in this education outreach program have been derived from atmospheric profiles such as these.
An Atmospheric Comparisons department has also been recently added to the MGS Radio Science Team education outreach program Web site. This department contains dozens of questions about the atmospheres of Earth and Mars. Registered participants in the outreach program may answer these questions using the martian meteorological data and visualization tools provided to them by the MGS Radio Science Team and meteorological data from Earth collected and recorded by their own class and the other participating classes in the outreach program. By comparing the meteorological data from the two planets, participants in the outreach program will learn much about the fundamental principles of atmospheres, weather and climate!
The MGS Radio Science Team will not be acquiring any new data until later this year. We hope to begin a second martian meteorological "campaign" in November. We will, of course, be collecting the bulk of our data during the mapping phase of the MGS mission beginning in March, 1999. If you are an educator and would like to register for the program, please contact joe@nova.stanford.edu. All of the martian meteorological data and the data transfer and visualization tools will then be available to you and your students!