Equality and the loneliest star in the sky

The time of the turning of the leaf and the turning of the year is here again. The wonderfully warm days of summer are shortening and cooling off. In fact, some places have already had a touch of the dreaded "S" word, snow.

The autumnal equinox -- when the Sun crosses the celestial equator heading south -- will be on Monday, Sept. 22, at 8:29 pm MDT.

Equinox is a word that means "equal night." However not every place will have equal day and night, it depends on their location and distance from the equator.

For instance, we who live along the 40th parallel (part of which is the Kansas/Nebraska state line) will not have just one occurrence where day and night are equal.

In fact we will have three days where the day/night time is close, but not actually equal.

On Thursday, Sept. 25, daylight will be 12 hours and four minutes long, on Friday, Sept. 26, daylight will be 12 hours one minute long, and on Saturday, Sept. 27, daylight will be 11 hours and 59 minutes long.

From the equinox on, daylight will shorten and night time will lengthen as we head toward the winter solstice in December.

As we have discussed before, the reason for the seasons in the 23.5 degree tilt of Earth's axis. As we go from summer into autumn, and Earth moves around the Sun in its orbit, it starts to lean the northern hemisphere away from the direct sunlight of summer into the slightly glancing blow of autumn and winter.

Conversely, our friends in the southern hemisphere are moving from winter into spring as they start to lean toward more direct -- and thus warmer -- sunlight.

Even though the early evening temperatures are starting to drop, it does not mean we can't still enjoy some of the celestial sights waiting for us over our heads.

The delightful Summer Triangle of Vega, Altair and Deneb is almost directly overhead and lower toward the eastern horizon the Great Square of Pegasus is well up in the sky. Although now the square looks more like a baseball diamond.

Last week we talked about Fomalhaut, the loneliest star in the sky. You can find it by looking very close to the southeastern horizon at about 8:00 pm, although an hour later it will be much higher to the south. It is the only bright star in that part of the sky.

For those of you participating in our Mars Watch, the Red Planet is now within five degrees, about the width of a binocular field of view, of Antares, the Rival of Mars. Antares is the brightest star in Scorpius, the Scorpion. Toward the end of the month we will be watching for a Mars-Antares-moon conjunction.

SKYWATCH: New moon, Sept. 24. If you have occasion to be up early around 5 a.m. on Friday, Sept. 19, check about halfway up the sky above the eastern horizon for a very skinny crescent moon. Take your binoculars out with you and look about seven degrees to the left -- about a width and a half of the field of view--for a nice little star cluster, M44, the Beehive Cluster in the constellation of Cancer, the Crab.

Just below the cluster is the bright planet Jupiter. The next morning on the 20th, the moon will be just below and right of Jupiter and on the 21st the moon has moved on to be very close to Regulus, the brightest star in Leo the Lion.

If you would like some consolation about winter coming just remember, Leo is a spring constellation.

NEXT WEEK: A pair of eclipses in October and more astronomical blathering.