Equinox isn't everything

Now that we have past the autumnal equinox things have settled down, well not quite. The temperatures are assuming fall proportions and are dropping rather precipitously in the evenings.

Equinox means equal day and equal night and supposedly on the day of either the autumnal or the vernal equinox (spring) daylight and dark will be equal. However, such is not the case. Due to that pesky 23.5 degree tilt of Earth's axis there are slight differences according to where you live.

Here in Southwest Nebraska the 12 hours of daylight and dark came on Monday, Sept. 26. On the day of the actual equinox (Thursday, Sept. 22), the time of daylight here was 12 hours and 10 minutes.

The only place daylight and dark are actually equal are on Earth's equator. However, the Sun does rise due east and sets due west on the day of the equinox no matter where you live.

I was going to wax further poetic concerning the equinox and changes in daylight and dark times, but there is just too much stuff to look at in the sky during this week. So dust off your binoculars, find a really good dark-sky place, dress warm, and bring your munchies.

1. Be outside anytime this week, looking low above the western horizon for the bright shining planet Venus. Start looking at least a half-hour after sunset and you won't miss it.

2. Swing your gaze slightly farther to the east and pick up Saturn and Mars. They are in the south with Saturn being just above the bright star Antares in Scorpius, Mars is just a little farther east.

3. Tonight, Wednesday, September 28, be outside after 8:00 pm MDT and put your binoculars on Mars, it will be in the same FOV (Field of View) with the really nice Lagoon Nebula (M8). Edge up just a little higher and find the Trifid Nebula (M20). All three objects will be in the same FOV.

4. Now swing your view to the east, just above the horizon, look for a giant square, which makes up the constellation Pegasus. It will look like a giant baseball diamond standing up on one corner. Alpheratz is the star on the left point of the diamond.

We are going to now look for one of the jewels of the sky, the Andromeda Galaxy. The star Alpheratz marks the head of the Andromeda Constellation, it consists of two lines of stars flowing down to the left (as you are looking at it).

Count out two sets of matched stars along those lines, when you get to the second set, draw a line between them going up (about four degrees). The object this line points to is the Andromeda Galaxy. If your location is dark enough you will be able to see using only your eyes, a tiny, faint smudge against the dark sky. Use your binoculars to make it a bigger smudge.

It's true nature will be shown only if you have a moderately large telescope.

One small bit of information, the Andromeda Galaxy is the most distant object you can see using only your eyes, about 2.9 million light-years.

5. Thursday, September 29, at about 6 am MDT, be outside looking east for a very slender, crescent moon. Floating just above the crescent will be the tiny planet Mercury. It will be visible in the morning sky until about October 10.

SKY WATCH: Friday, Sept. 30, new moon. On Monday, Oct. 3, look west about 30 minutes after local sunset for a thin moon floating just above the bright planet Venus which you found earlier.

NEXT WEEK: More things to look at with binoculars, and more astronomical blathering.