Incoming President John Bell opened our first meeting of 2002 at 7:30 PM in 300 Lawrence Hall, Sul Ross Campus.  There were 24 people present.  Bill Wren presented a program on the new Astronomy Education Center at McDonald Observatory (see below).
       A Reminder:  Because we decided to have our regular meetings for the first half of 2002 in Feb-ruary, April, and June, there was no meeting in January 2002.  This of course explains the ab-sence of any minutes from the January meeting.  Our next meeting will be on Wednesday, April 17, at the usual time and place.
       Treasurer's Report.  Treasurer Betty Grimm, was out of town at the time of our meeting.  How-ever, she submitted the following written report:

       Bill illustrated his presentation with a large number of excellent slides.  A satellite photo of the McDonald complex showed its major features very clearly, the domes, ancillary structures, and roadways.  Interior photos showed the historic 82" scope, the world's second largest when it was installed in 1939;  the 107", second largest in it's day; and the Hobby-Eberly 11-meter scope (about 440"), perhaps the third largest scope in the world, depending on our choice of comparisons.
       The new Visitors Center will incorporate many features of the existing center.  The new facility is expected to be the largest center for astronomy education in the country.
       The kinds of questions that visitors ask have motivated many of the exhibits and displays.  For example, how do we know what an astronomical object is?  How do we know its temperature, and how far away it is?  Spectroscopy, studying the color and wavelength of light emitted by different elements, provides answers to these questions.  Prisms, and more recently diffraction grat-ings, separate the light from an object into its component wavelengths and colors.
       Spectroscopy makes it possible to determine the chemical makeup of the stars by analyzing their light.  Each element has a characteristic set of emission lines, bright lines in various regions of the spectrum, that appear when the element is heated to a high temperature.  Light passing through a cool cloud of gaseous elements produces dark absorption lines of the same wavelengths as the elements emission lines.  A classic example of the power of spectroscopy was the discovery of the element helium on the sun in the 1800s - before it was discovered on the earth. 
       Besides determining the chemical composition of  astronomical objects, spectroscopy can also determine the motion of objects in relation to the earth.  For objects moving toward us, spectral lines are shifted toward the short-wavelength end of the spectrum, toward the blue.  For objects moving away, lines are shifted toward the long-wavelength end, toward the red.  The light from very distant galaxies and quasars is highly red shifted, hence the notion of the expanding uni-verse and the big bang.
       A grant of $1 million from the National Science Foundation has funded a 9" heliostat, a device that will produce a spectrum of the sun's light 10 feet long by 10 inches high.  The spectral lines  of the various elements in the sun will be labeled.  The spectroscopy theme will carry through in the glazing of the windows of the gift shop in the colors of the solar spectrum.
       We look forward to the opening of this handsome new center in about two weeks.

       (NASA, February 26, 2002)  The Moon will become full on Feb. 27th. It happens every 29.5 days, yet this full Moon is special: It's the biggest and brightest of the year.  "Not all full Moons are alike," says astronomy professor George Lebo. "Sometimes pollution or volcanic ash shades them with interesting colors.  Sometimes haloes form around them - a result of ice crystals in the air."
       "This full Moon is unique in another way," Lebo says. "It will be closer to Earth than usual. The moon's orbit around our planet is not a perfect circle," Lebo explains. "It's an ellipse." At apogee the Moon lies 248,000 miles from Earth.  At perigee, it's closest approach to the earth, the Moon is only 217,000 miles away - a difference of 30 thousand miles.
       When the Moon is full on Feb. 27th it will be near perigee. As a result the Moon will appear 9% wider than normal and shine 20% brighter.  The extra moonlight is caused, in part, by the Moon's nearness to Earth. But that's not all. The Sun is closer to Earth, too. Lebo explains: "Every year during northern winter, Earth is about 1.6% closer to the Sun than normal. The Moon reflects sunlight, so the Moon is brighter during that time."  (This effect should not to be confused with the famous "Moon Illusion" - a trick of the eye that makes Moons rising near the horizon appear swollen. The nearby full Moon this week really will be bigger and brighter.)
       The first three full Moons of 2002 are all brighter-than-average.  All three happen when the Moon is near perigee, and when Earth is relatively close to the Sun.  Full Moons later this year will be smaller and dimmer by comparison.  For example, August's full Moon - an "apogee Moon" - will be about one-third dimmer than February's.  But will anyone notice the difference?  "The human eye can easily discern a 20 or 30% difference in the brightness of two similar light sources," says eye doctor Stuart Hiroyasu.  By that reckoning, a sky watcher could tell the difference between a bright perigee Moon and a dimmer apogee Moon.  But the two Moons would have to be side by side to effect the comparison - not likely except in a science fiction movie!
       Even the dimmest full Moons are very bright, notes Lebo.  They outshine Sirius, the brightest star in the sky, by twenty-five thousand times.  They cast shadows, and provide enough light to read by.  "There's really no such thing as a faint full Moon. It's all relative."
       Nevertheless, some sky watchers will sense that this Moon has something "extra" - particularly northerners.  Many northern landscapes in February remain covered with snow. Snow reflects about two-thirds of the light that hits it, while bare ground reflects only about 15%. A snowy moonlit landscape always seems remarkably bright.  Perigee, perihelion, snowy terrain - they all add up to a big dose of Moonlight. Can you tell the difference? There's only one way to find out: Go outside and look!