THE MOON: MODELS, MEMORIES, AND MYSTERIES

Join us at 8:00 on July 17 at Explorit for a slide show and demonstrations involving our natural satellite, the Moon.

Models will help us visualize how large the Moon is compared to the Earth and how distant it is; how the phases of the Moon occur and why eclipses don't occur each month. We will commemorate the Moon landing thirty years ago this month, when men walked on the Moon for the first time. Among other findings, the Apollo missions returned evidence that the Moon and Earth were created at different times and that the Moon was created later, perhaps as a result of a collision between a large planet and the Earth .

Next, our discussion will focus on why the Earth and Moon are so different in appearance. Why has the Moon so many craters? How are the associated rays created? We will make a crater and review the characteristics of craters on the Moon. We will also see slides depicting the current Lunar Prospector mission to the Moon, which has resulted in one NASA estimate that 33 million tons of water ice may exist at the Moon's poles. We'll consider what that ice could mean to the possibility of establishing a Moon base.

Weather permitting, we will adjourn to view what some astronomers have called "our sister planet,' the Moon. Did you know that the Moon and Mars are the only objects whose surface features we amateurs can view with our telescopes? We will discuss what to look for and how amateur astronomers are contributing to ongoing scientific investigations of the Moon's mysteries.

Partial LUNAR Eclipse on Wednesday, July 28!. The Moon's southern hemisphere begins entering the Earth's outer, less dense, shadow ("penumbra") at 1:56 a.m., but the first visible shading will probably occur around 2:50 a.m. By 3:22 a.m. the Moon will enter the central area ("umbra") of Earth's shadow, and 4:34 a.m. will mark the middle of the eclipse. An hour and 12 minutes later, the Moon will emerge from the "umbra." The sun will rise at 6:11 and the Moon set at around 7:70 a.m. More details are available in Roger W. Sinnott's article in the July Sky and Telescope Magazine (pages 108-110)

The June Meeting: "A June Night, Some Moonlight, And You" was our meeting's theme at Fairfield Elementary School on June 19. The Moon was at first quarter and quite bright. Attendees brought two 16" telescopes, one 12" one 8" and one 6"-all of the Dobson design. We almost had more experienced amateurs than guests during the evening, and so everyone learned and saw many new things.

Mars gave us moments of exceptionally good seeing - the best I can recall from Davis. Despite the moonlight, we had good views of several planetary nebulae including: the "Cat's Eye" (NGC 6543) in Draco, the "Blinking Nebula" (NGC 6826) in Cygnus, the "Dumbell Nebula" (M27) in Vulpecula, the "Ring Nebula" (M57) in Lyra and several of brighter galaxies. (Incidentally, if you're interested in planetary nebulae I recommend "The Planetary Nebulae Observer's Page" at http://www.blackskies.com/index1.html) Thanks to all who "fought the moonlight" to share with us the beauty of the night sky. Thanks also to the Davis Joint Unified School District for allowing us to use the playground at Fairfield School.

DAVIS SKY IN JULY

PROMINENT CONSTELLATIONS visible in the sky around 9:00 PM in July are: (1) in the West: Leo (the Lion); (2) overhead: Bootes (the Herdsman), Hercules (the Hero), Lyra (the Lyre); (3) in the East: Cygnus (the Swan), Aquila (the Eagle); and (4) in the Southeast: Scorpius (the Scorpion) and Sagittarius (the Archer

The Astronomy Club is hosted by Dennis Smith with the assistance of Tim Feldman and other eager astronomy buffs. The club is for everyone - adults, children, knowledgeable or ignorant. Come to listen, look and learn, or to share your expertise or experience.