SJAA

Ephemeris

Mooning

Dave North


This is a month of extremes: the "prime events" of the month happen at new and full Moons!

First, the new moon.

Of course, you won't be able to see it because it's buried in the glare of the sun. But "new" is also the time of the greatest northern declination of the moon this month, which means this will be one of the best opportunities to play the "early moon game." The idea is to see how soon after new you can spot the moon.

Actual "new" will be just before 7:30 p.m. on the 12th, but of course the sun will still be in the sky.

I highly disrecommend trying to spot it this evening. For one thing, you probably won't. For another, it's just too dangerous even if you do know what you're doing.

But the night of the 13th is another story. Then the moon will still be up (though very near the horizon) just after sunset - when the sun cannot hurt you.

There will be quite a bit of glare yet, but you should be able to get a peek. A one day moon is not any kind of record, but it is fun, and sometimes you can even get detail through the murk and brightness, which is a small reward unto itself. On the next night, success is virtually assured, and the view even better!

But what's happening at the full moon?

Right on the day of the full moon, in the early morning of the 28th, there will be a partial lunar eclipse visible from around here. The hour is a bit inconvenient (about 4:25 am) and there isn't a great deal to see in such a minor partial, but it still should afford some interesting views.

The best "trick" is to use some magnification and get the brighter (northern, in this case) part of the moon out of your eyepiece field, so the most "color" can be seen. This does present something of a paradox though: color is usually best seen at low magnification. So another technique is just to "shove" the bright part out of the field at low mag.

The night before, however, is the most interesting event from my point of view. During the best viewing hours (around 10 p.m. on) the moon will be as high as it will get near full this time of year (which is not very high at all) but it will also have a pretty good libration of the western limb... where the Eastern Sea (Mare Orientale) lives. The terminator should be almost perfectly placed around midnight for a look at this incredible impact basin, along with its "shock ring" Rook and Cordillera mountains.

It's not unusual to see some truly weird formations, including a seemingly huge mountain sticking up into the sunlight. For those of you who haven't yet hunted Orientale, it's almost unbelievable how cool this looks.

And for those of us who have, it's an event to anticipate all year.

Alternate months around this time afford the best opportunities due to the "incremental" half-day differences in terminator placement each month, so the next really good shot will be in September. But that is no reason to avoid an August attempt, which will be mentioned next month.

Otherwise, just enjoy the early days of the moon this month -placement will be good, and first quarter should still be fairly high.

Oh, there is one "pseudo" event too: on the 15th there will be a tight grouping of the Moon, Venus and Regulus, best seen in the early evening.

Well worth a look!


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