TES News

February/March, 1993, Volume 2, No. 1

Thermal Emission Spectrometer Project
Mars Observer Space Flight Facility                             
Department of Geology, Arizona State University
Box 871404, Tempe, Arizona 85287-1404, U.S.A.

Mars Observer TES Enroute to Mars!

Mars: The Arizona Connection*

For nearly a century, scientists have come to Arizona to study the planet Mars. The first was Percival Lowell, who built his Flagstaff observatory in 1894. Over the next two decades, Lowell popularized the idea that Mars was crisscrossed by a network of canals built by a martian civilization. Could this be true? A planet that has liquid water somewhere on its surface is considered to be a good place to look for life. Lowell and many of his contemporaries thought that they had evidence of such water in the form of canals and oases.

It became crucial to determine the temperature of Mars, to see if it was warm enough to keep water from simply freezing. The temperature of a planet can be measured through a telescope using an instrument called a thermal infrared radiometer. Thermal infrared energy, which has wavelengths about 10 to 100 time longer than visible light, is more familiar to us as "heat." A thermal infrared radiometer can determine the temperature of something without actually touching it.

In the 1920's, William W. Coblentz, a scientist from the U.S. Bureau of Standards, came to Arizona to measure the temperature of Mars using the telescopes of Lowell Observatory. Two decades earlier, Coblentz distinguished himself as a pioneer in the field of thermal infrared spectroscopy. The measurement of thermal infrared energy emitted or reflected from a substance over a range of wavelengths provides a "fingerprint" unique to each material. Coblentz was the first to look at the thermal infrared spectra of a variety of rocks and minerals.

Coblentz and his colleague Carl O. Lampland were among the first to point thermal infrared radiometers at Mars. With an average temperature below 0 degrees C (32 degrees F), they found that Mars is a chilly planet, although sometimes in summer the temperatures can rise above freezing. If Mars is sometimes warm enough to melt water, it was argued, then conditions might also be right for life to exist on the Red Planet. These temperature measurements, however, did not account for a fact learned later by astronomers-- that the atmosphere of Mars is too thin to allow liquid water to survive on the surface without rapidly freezing or evaporating.

The Mars Observer Thermal Emission Spectrometer (TES), soon to orbit Mars, combines both aspects of Coblentz's pioneering thermal infrared studies. The TES is a high-tech device that can determine both the temperature and mineral composition of the martian surface. Like Coblentz, the TES science team will conduct their studies of Mars from a facility in Arizona-- this time on the ASU campus in Tempe. Determination of martian surface temperatures is useful for modeling the climate, observing the seasonal growth and retreat of the polar caps, and determining the particle size of loose sediments. TES will also help monitor the amount of dust, water, and carbon dioxide ice suspended in the atmosphere.

To Mars!

Titan III rocket carrying Mars Observer lifts off from the Kennedy Space Center, Florida, at 10:05 a.m. Arizona time on September 25, 1992. The spacecraft will reach Mars on August 24, 1993.

Mars Observer Launched!

In late September 1992, the TES Science Team, staff members, and five ASU graduate students held a team meeting at the NASA Kennedy Space Center in Florida, to assess the status and plans for the TES experiment aboard Mars Observer. Then, in the early afternoon of September 25, 1992, they gathered at the V.I.P. viewing area along with other Mars Observer lifted off from its launch pad and roared over the Atlantic, into the ocean of space.

"From here the launch was spectacular!" Philip R. Christensen, TES Principal Investigator and ASU Professor of Geology, telephoned from Florida, "the excitement from the ground was incredibly high as it took off."

A few TES personnel stayed in Tempe to celebrate the Mars Observer launch with ASU students, faculty, and staff. Nearly 100 people attended the ASU event. Visitors watched one of three televisions tuned to the NASA Select channel while snacking on miniature Mars (TM) candy bars. The Mars Observer launch took place at 10:05 a.m. Arizona time.

Mars: The Arizona Connection.*

Martian volcano Olympus Mons is taller than any mountain on Earth. It is about 6 times higher and 50 times wider than the San Francisco Peaks volcano near Flagstaff, Arizona. Figure prepared by S. Meszaros of Phoenix. Available as NASA #83-H-246 from the National Space Science Data Center, Code 933, Goddard Space Flight Center, Greenbelt, MD 20771.

TES Checks out "Fine"

Mars Observer, speeding toward the Red Planet at over 16 kilometers per second (36,000 miles per hour, relative to Earth), will reach Mars on August 24, 1993. It will take about 4 months to adjust its orbit until it is circling 378 kilometers (235 miles) above the surface. It will then begin a detailed mapping program that will last through 1995.

Periodically during the cruise to Mars, NASA turns on the Mars Observer instruments to assess their status and check their calibrations. The TES was first turned on November 18, 1992, for a total of 65 seconds. The data from TES were received with cheers by the TES team members and visiting reporters at the ASU Mars Observer Space Flight Facility. TES was seen to be in excellent health. A second turn-on, lasting more than two hours, took place of February 12, 1993. Now, the TES team eagerly awaits August, when Mars Observer will become the first U.S. spacecraft to reach the fourth planet since 1976.

Educational Outreach

While the TES team is busy with the mission and scientific analyses of TES data, efforts are underway to explain the project to the public. The Mars Observer Space Flight Facility is designed with visitors in mind. Pictures and displays outline the Mars Observer and TES mission. Educational videos and NASA Select TV are shown on a monitor in the lobby. Eventually, new images of Mars from the Mars Observer Camera will also be displayed. Huge windows in the Facility allow visitors to see the TES team at work, either analyzing TES data or testing computer commands on the full-scale TES engineering model.

Groups of school children frequently come to the facility-- visits can be arranged through the ASU Visitor Center, (602) 965-0100, or the Mars Observer Space Flight Facility, (602) 965-1790. The TES group is also beginning a series of Educators' Workshops, the first was held on February 20, 1993, and attended by more than 130 (K-12) teachers.

  NOTE ADDED 27 Jan. 1994:  
The ASU Visitor Center no longer handles 
tours.  Please call (602) 965-1790 if you 
have questions about visiting the facility.

Recently Published:

Kieffer, H.H., B.M. Jakosky, C.W. Snyder, and M.S. Matthews, eds. (1992) Mars, University of Arizona Press, Tucson, 1498 p.

[A comprehensive review of everything we know about Mars. H.H. Kieffer is a TES scientist.]

Mars Maps:

U.S. Geological Survey, Map Distribution, Box 25286, Denver, CO 80225.

Mars Globes:

Sky Publishing Corp., P.O. Box 9111, Belmont, MA, 02178-9111.

Planetary Society Mars Contests:**

[a] Mars Institute Contest, open to high school and college students (deadline: 5/17/93).

[b] Name the Russian Mars Rover (to land in 1997), open to kids born between 1/1/80 and 12/21/84 (deadline: 10/1/93).

** Contact: The Planetary Society, 65 N. Catalina Ave., Pasadena, CA 91106.

* TES News will occasionally highlight connections between Arizona and Mars.

Text by:  

K. S. Edgett

Assistance with original text:
T.E. Montoya

Reviewed by:
TES staff

Original Text:  February 1993
This On-line version:  January 27, 1994