Opinion

The steam from the tea pot

Thursday, September 17, 2009

Time for a change. With the kind of weather we have been having here in Southwest Nebraska lately, it is time to change from T-shirts and shorts to longer sleeved shirts and longer pants.

It is also time for a change of seasons. Autumn will start officially on Tuesday, Sept. 22, at 3:19 p.m. MDT. That is the time the sun will cross the equator traveling south.

Thanks to that pesky 23.5 degree tilt in Earth's axis, the northern hemisphere is being tilted away from direct sunlight and the southern hemisphere is being tilted toward it. That means our good friends down south will be starting spring with warmer temperatures, longer days, and shorter night.

Conversely, our days are shortening and our nights lengthening. For example, on Sept. 1, sunrise was at 6:13 a.m. and sunset was 7:18 p.m. On Sept. 30, sunrise will be 6:41 a.m. and sunset at 6:31 p.m. All times given are Mountain Daylight Time.

If my math is correct, (and I know someone will be checking it) for September the sun is rising 28 minutes later and setting 47 minutes earlier. It gets worse as the months progress toward winter.

That crossing is called the Autumnal Equinox. Its counterpart is the Vernal Equinox when spring begins. Equinox is a word having to do with equal night and day.

If you are interested, the day which does have equal night and day (at least for us folks here at 40 degrees north of the equator) is Saturday, Sept. 26, when the Sun rises at 6:37 a.m. and sets at 6:37 p.m. MDT.

The equinox is also the day the sun will rise due east and set due west. To check this out find a nice, straight, east/west road and look at sunrise and sunset. The glowing orb will rise directly over the middle of the road.

SKY WATCH: New moon Sept. 18. The only planet visible in the evening sky now is a very bright Jupiter in the southeast after sunset. Venus and Mars can be located in the east during the early morning hours. In the early evening hours a very slender crescent moon will be next to Antares, the heart of Scorpius, the Scorpion in the southwest on Sept. 23. The Summer Triangle is still high overhead at dark-thirty but is slowly drifting west as the evenings pass. To the left of Scorpius is the tea pot shaped constellation Sagittarius. Use your binoculars and search the area between Scorpius and Sagittarius for the many faint fuzzies located there. Star clusters and nebula abound in that area. Two of the best are just above the tea pot. The Trifid Nebula, M20, and the Lagoon Nebula, M8, can be seen from a dark-sky place without any optical aid. They usually can be placed in the same field of view in binoculars and are a visual treat in a telescope. The Milky Way looks like steam rising out of the tea pot's spout.

The area just above the spout is the location of the center of our galaxy. It is a very bright area of hundreds of thousands of stars. It is too bad that all that light is blocked by a lot of dust and other obscuring material, so much so that we can't see it. However, astronomers using infrared telescopes can see through all that dust into the center of the galaxy and have confirmed that there is a black hole residing there.

NEXT TIME: More astronomical blathering.

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