Wednesday, October 1, 2014

The October Sky and Tonight's Sky for October 1

It's a new month and that means a new sky, at least for the trailing end of the night. Last month saw the Autumnal Equinox, the first day of fall. Around the turn of fall, the days shorten at their fastest pace, peaking at a loss of around 4 minutes a day. As a result, the October sky isn't all that much different than it was in September until just before the increasingly delayed dawn. So, to delay the onset of carpal tunnel as much as possible, just follow this link to the September sky guide from last month. My hands thank you!

Cool Constellations
The place where the October sky differs from that of September is in the early morning/predawn time frame, which allows for one to see the winter constellations earlier and even get a quick peek at the spring ones, too. With the increasingly delayed sunrise coupled with the weeks just prior to the return of Standard Time, October presents a great opportunity to get a spring (yes, spring!) preview before we let the clocks fall back and, in turn, kill any opportunities for early morning observing, at least for a few weeks. In October, Leo makes its return, bright blue Regulus appearing just ahead of the rising Sun in the morning. Just before the sky starts to get light, look for the head and front of Hydra peeking up over the Eastern horizon. By now, the Big Dipper is climbing and vertical, too.

Planetary Perceptions
Like September before it, October isn't shaping up to be all that great of a month despite all of the 5 classical planets being visible. Why? Most of the planets are rather close to the Sun. Starting in the evening, both Mars and Saturn are visible, though both are now pretty much dusk objects from all but the most unobstructed viewing locations. By month's end, Saturn will have disappeared into the Sun's glare. In the predawn sky, Venus hangs just above the Eastern horizon in the predawn sky but October heralds the end to this exceptionally long apparition of Venus that began back in the spring. On the other hand, Jupiter is visible for pretty much the second half of the night, coming to its meridian transit at dawn come month's end. Mercury? Well, the bad news is that one can pretty much forget about seeing it for the first three weeks of the month. The good news: come the last week of October, it will quickly pop out from the Sun's glare in the predawn sky in what will be its best morning appearance of the year, which will take place around Halloween.

Mark Your Calendar Days
October also brings two days that should be marked on your calendars if you live in North America: the night of the 7th into the 8th and the 23rd. Why? Both dates bring eclipses that will be visible in North America. On the night of the 7th/morning of the 8th (depending on whether you prefer to stay up late or get up early), there will be a total lunar eclipse visible for all of North America. The bad news is that only the West coast states will get to see the event from start to finish but the good news is that even New England states will get to see totality just before the Moon sets in the morning. Two weeks later on the 23rd, there will be a partial solar eclipse that will be visible in the entire continental United States as well as Alaska and Canada. At maximum eclipse, the Sun will appear similar to about a 3-day old Moon. As always, one should never look at the Sun without proper eye protection, whether in the form of a #14 or darker welder's shield, eclipse glasses, or solar filters for binoculars/telescopes.

And an Oddity . . .
While not two Full Moons, October of 2014 is notable for the fact that it contains two First Quarter Moons, one on the first and the other on the last day of the month.

Tonight's Sky for October 1: First Quarter Moon

Today, the Moon, second brightest object in the sky, has reached the First Quarter phase, which means that it is exactly 90 degrees around its orbit of Earth.

As for lunar mechanics, the Moon is always half lit. The reason we don't always see it as such is thanks to orientation in relation to us. Right now, with the Moon at a 90 degree angle relative to the Earth and Sun, we see the Moon as half lit and half dark, leading to the popular, erroneous phrase 'half Moon.'

After today, we will see more and more of the Moon as its lit side turns more toward us as it heads for a straight line in Sun, Earth, Moon order, and thus Full phase.

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