SJAA

Ephemeris

Mooning

Dave North


As I write this, I have no idea how last month's eclipse went for our various club travellers. We have to produce articles for the Ephemeris almost a month before they hit your mailbox, so things sometimes seem out of whack.

I'm pretty sure it happened, and hopefully someone from around here saw it.

Meanwhile, we're back on the hunt for Orientale, at least briefly.

Another thing I don't know is how well the August apparition went -July was something of a disappointment and September's showing has similar numbers.

Still, the July sky was both nervous and wet, so who knows? Maybe the same kind of libration and terminator will give a good view this time. The numbers work out slightly better this month, and it only takes a minute, so...

Be armed and ready a couple of hours past sundown on September 24. The terminator will slowly be revealing more of Orientale most of the night, but I suspect the best window will be from about 9:30 p.m. until about midnight. This may work out for just about any location in the U.S.

As usual for these events, the declination will be a little low (about -4 degrees) but that will be an improvement over both July and August. Might mean a bit steadier views, anyway.

We did manage during the July showing to home in on the Big Weird Mountain, and it turns out it has no name on any charts that were handy, which is actually good! I can keep calling it the Big Weird Mountain.

There is a short lesson to be learned from this whole thing, though. A couple of rules that run contrary to rumor:

1. There is always a terminator, even at "full" moon.

2. Some things are best seen at full. Especially polar features and anything that sits near the limb, or is in a libration zone.

So don't worry too much about the meepers who complain about the full moon, then look at you like you're nuts while you drag out your scope.

They don't know nuttin'.

One question that comes up now and again is: how long do you look at The Moon in any particular observing session?

So far, the answer is between one minute and about six hours. Neither is common, and one minute would be far more usual than six hours.

A typical short session will be early in the month, when there isn't much to see other than the crescent through binoculars, or perhaps Mare Humboldtianum as a splotch. I look, grin, and do some double stars.

Another short session might be on a night when the seeing is awful. When that happens, a good low-power view is about it.

Then again, sometimes the seeing is incredible and The Moon is high, and there's plenty of time. These sessions can be a bit harrowing at time, especially for the squirrels in the back yard.

A stint at the eyepiece, a few notes jotted down, look again, race to get that other atlas that show what this might be or that... look again... the phone rings... a curious detail that needs a quick sketch for later reference... look again... setting up another scope or two for more aperture, or better tonality, or... etc.

There ain't no rules. We're just doing this for the fun of it.


David North; last updated: October 04, 2007 Prev Next