by Richard Ozer
I almost bit the bullet and went to Montebello when Paul S. posted his OI, but laziness prevailed and I drove the 5 minutes to Chabot instead, with the intent of setting up my scope for public observing.
It was a relatively quiet night with only fifty or so people showing up to observe through the half dozen scopes that were there; four amateur scopes and the two historical refractors that draw the public.
As I was setting up, a loudly screaming pack of cub scouts arrived to watch the space station fly overhead. I never know when that's going to happen because I don't follow such events. Anyhow, it was fun to watch as it faded away in the eastern horizon. I figure the astronauts get to watch a half dozen sunsets a day. Many of the kids were in disbelief that there were really people up there right now. Half of them had no idea it even existed. [Begin political rant...] After the billions spent on constructing the thing, it's a shame that the schools have no formal curriculum (video feeds or otherwise) to get young students connected to the science activities on board. It's beginning to look like ISS is for billionaire tourists only [end political rant...].
Another surprise was an hour or so later, when the Hubble space telescope flew by. A few of us were wondering about its seemingly odd orbit... does anyone know anything about its orbital characteristics, or am I only imagining that I remember something about the Hubble orbit that maximizes its time in shadow?
The inversion layer was just below the observatory, so it was quite dry until about 10:30 when dew formed with a vengence. In the meantime, however, I got phenominal detailed views of Jupiter, including storms on the NEB; brown barge and white oval. By the time I set up, the Spot Formerly Known as Red was moving out of view, so I didn't have the opportunity to look for the current storm collision. Before things dewed up, we also caught the transit of Io. Jupiter is so bright for a 10" reflector, I stopped it down with an off axis mask, significantly enhancing the contrast at the expense of some color.
Saturn was also nice to view. I boosted the magnification as high as I could, but saw no sign of the Encke Gap/Keeler Gap we were debating last week. The Encke minima was barely detectable and I continue to doubt my sanity regarding my earlier claims.
I've learned, at public events, to keep it simple. Keep the magnification no higher than 120x because kids and first time observers have a really hard time with high magnification eyepices, even those with good eye relief. Also, I never view anything that takes longer than 20 seconds to find because human beings are "hard wired" to grab and move whatever is in front of their face, be it eyepieces or bananas.
With this in mind, I decided to let the big refractors steal the planet show and turned my scope to M42 to talk a bit about steller evolution. To illustrate the sheer size of the nebula, I used part of Andrew Bell's explanation he gives at Project Astro sessions; "if you are at one end of the nebula with a really bright flashlight, and your friend is at the other end, and you blink the light, it will take some thirty years for him to see the light blink." That gets people thinking so hard, it will often keep them up at night.
The seeing was steady enough to find all six of the higher magnitude stars in the trapesium; all visible as perfect pinpoints of light. There was speculation about a seventh star, alongside the B star, by a couple of observers, and I was convinced I could see one too. However, a quick look at a star-chart confirmed that it was an impossible observation and was due to vibration, imagination, or was a background star completely unrelated.
Finally, I turned the scope to M81 and M82 to give people an opportunity to gaze at something really far away that doesn't require averted vision. Many were amazed that humans have known about these objects since the 1700's. I also find it somewhat humbling that we have only figured out what they are in the last fifty years.
Overall a fun night of non-serious observing (i.e. no Herschel objects in Camelopardalis). Thankfully, the dew settled in before the screaming Cub Scouts came back after their pizza, sugar and planetarium show; so I was packed up and gone before the damage potential peaked.