"STAR PARTY" at Hansen Dam

The Sidewalk Astronomers and the East Valley Coalition held a "Star Party" late Friday evening at the Lower Hansen Dam Park. Word of mouth, flyers and a tiny notice in a valley newspaper alerted interested stargazers about the 7:30 event.

It was a perfect night – balmy, calm, and most importantly… clear. At least four previous parties had been cancelled due to unexpected overcast. Enthusiasts were holding their breaths late Friday afternoon as intermittent clouds scuttled across the sky, but by sundown it was "all systems go."

I arrived at dusk, just as members of the group began unloading equipment from their trucks and vans. I was amazed at what I saw. If I hadn´t spoken earlier with Bob Alborzian, a long time member of the Sidewalk Astronomers, about the simple homemade telescopes they used, I wouldn´t have believed my eyes.

First he unloaded a plywood, box-like, unit that swiveled on a flat wood bass. Eager to show me everything, he loosened a wing nut and lifted off the top. An old 33-rpm record and a few small Teflon strips accounted for the smooth swivel. At the top of the box, 4-inch half-circles were cut out of two opposing sides. Bob pointed to a trio of small Teflon buttons in each cutout.

By this time, a small crowd of adults and kids surrounded us and Bob slipped into lecture mode as easily as his device swiveled on that old LP. He called the "box" a Dobsonian Mount after John Dobson, the man who designed it and founded the Sidewalk Astronomers in 1968.

Next Bob brought out an 8-inch diameter cardboard tube, about four feet long (the kind used for pouring concrete columns). It had colorful plastic shower caps on each end "to protect the mirror from dust."

Mounted flat on either side of a plywood frame about two-thirds down the tube were a pair of thin pieces of 4-inch plastic pipe. These rested snuggly in the cutouts on the base and allowed the tube to tilt up and down. The whole apparatus looked like a cannon.

At the long end of the tube, protruding off one side was a small, adjustable "eyepiece." Bob removed the shower cap from that end and allowed me to look down the barrel. I saw a highly polished mirror at the other end, and a small disc suspended in the center and angled directly at the eyepiece. It would reflect the light gathered by the mirror into the eyepiece and …do what?

How could this simple – obviously low cost – homemade "telescope" see the craters on the moon, let alone Jupiter with four of its seventy-one moons, 500 million miles away? I was eager to find out, but it wasn´t dark enough, and the two celestial bodies had not yet risen.

Meanwhile Jason and Danita Poss set up their telescope. Danita said they´d made this one for someone else and were in the process of making one of their own. She showed me a thick, 8-inch-round slab of glass wrapped in soft cloth that she´d been working on. She explained how nearly 40 hours of patient hand grinding and polishing - with different size grit - would be necessary before the perfectly concave surface would be mirror-coated.

"How do you make it perfect?" I wondered. "What if you make a mistake and get it oblong?" She repeated Bob words, "There´s no mistake that can´t be corrected. That´s why even 6-year-olds can do it."

Tom White´s "scope" was the largest, at about 5.5-feet long. He made his mirror from a 10-inch piece of porthole glass. He´d also mounted a Telrad on the top (a type of scope with a bulls eye site to zero in on the object), and a huge protractor around the base to show degrees of swivel. "I made that at work," he added shyly.

Paul Keen set up a small homemade telescope alongside a commercially built one. Later, he commented that the "Dobsonian" had the stronger magnification.

More families gathered to examine the equipment and talk to the friendly Sidewalk Astronomers. (I later learned that hosting free star parties where people can look through telescopes, hear details about what they were seeing, and enjoy the beauty of the Universe, is the organization´s main objective.)

Finally it was dark enough, and telescopes began focusing on the stars overhead. My first glimpse was of Albireo, a blue and gold double star. "The two rotate around each other," Bob explained.

"By the way," he said, nullifying a favorite childhood rhyme, "stars don´t twinkle. It´s the dust pollution in our atmosphere that makes them look that way." At my crest-fallen look, he whispered, "But I never tell that to children under six."

I walked from one telescope to another as the owners focused on differed stars, described what they were, and answered questions. I saw the Ring Nebula through Tom´s scope; a fuzzy donut of stardust made when a star exploded. Then, a brilliant "star" rose on the horizon, and scopes swung on their swivel bases, tilted down, and re-focused.

As I gazed through Bob´s telescope I gasped. Shining brightly, at dead center with three smaller lights to the right and another to the left was Jupiter. "The image you see left the planet 45 minutes ago, traveling at 186,000 miles per second," he told us. "Thirteen hundred earths could fit inside Jupiter; those four moons you see are larger than ours." (Jupiter has 71 moons, but we only see four of them, and they are bigger than our moon.)

Then a huge gold orb peeked above the horizon and climbed above the trees – an almost perfect Harvest Moon. "Pollution," Bob teased when I remarked about the color. Scopes lowered and re-focused. Tom´s big instrument got a new eyepiece. I bent and looked.

Great shadowed craters appeared on the lunar surface along with flats and spirals. "Rocks on a full moon are as hot as boiling water," Bob said. "The moon doesn´t rotate. Its back side is frozen."

At 9:30 the young kids had gone, but a few die-hard adults stayed, listened and learned. The next Star Party at Hansen Dam is on October 2, but Bob invites everyone to his August 27, Stargazing event on the Chandler Bikeway in Burbank.

Call (818) 841-0548 for information and visit www.sidewalkastronomers.us (Bob also teaches astronomy and telescope building to 8-12-year olds on Tuesday evenings.)