Last-minute astronomy gifts, and the true length of days

Wednesday, December 24, 2014

Before I get involved with the rest of this, I want to wish each and everyone of you a Merry Christmas.

Speaking of which, it may be a little late now, but here are a couple more gift ideas for the astronomically minded person on your gift list.

Probably one of the premier books for any astronomer is "Nightwatch," by Terence Dickinson, published by Firefly Books. Not only is there a wealth of information, there are some great maps of the sky to help locate those objects you will be looking for.

Another good addition to the astronomy library is "The Monthly Sky Guide," by Ian Ridpath and Wil Tirion published by Cambridge Press.

Both are available on-line.

Did you enjoy Solstice Day last Sunday, Dec. 21? The day when the Sun was as far south as it gets for the year, and then starts its journey back north giving us longer days and shorter nights.

Folklore holds that the winter solstice is the shortest day and longest night of the year, but if we look at sunrise/sunset tables we find that is not always the case. In fact the days on either side of the solstice are often of the same length.

For example, starting on Dec. 19, and continuing to Dec. 25, the length of sunlight will be nine hours and 19 minutes for each day. After Dec. 26, the length of daylight begins to grow.

If you would like to have a chart of sunrise/sunset times, point your favorite browser to: Enter your location and print out your chart.

The night sky is getting busier. Venus, the second planet out from the Sun, will be joining us in the early evening sky. Look in the southwest sky about a half-hour after local sunset for a bright dot just above the horizon. It will get higher as the days progress.

Just make sure you have a clear, uncluttered horizon so nothing gets in the way.

The appearance of Venus just after sunset often gives rise to a lot of UFO calls because the planet does resemble a flying space craft, but it is all an optical illusion.

It will be joined by sister planet Mercury after the first of the year. The pair will rise higher together in the sky each evening.

Beginning Jan. 3, the pair can be viewed in the same binocular field of view and will be closest on Jan. 9. They will continue to be close until Jan. 20.

Jupiter will be low in the west after 10 p.m. local time. It is currently above Regulus, the brightest star in Leo, the Lion; the ringed planet, Saturn, returns to the morning sky about an hour before local sunrise.

It is just above the emerging head of Scorpius

A slender crescent moon will bracket the outer ice-giant planet Neptune on Dec. 25-26, and be near another outer ice-giant, Uranus, on Dec. 28.

It may be difficult to see because the moon will be past first quarter, but it will be near the Pleiades star cluster on December 31.

SKYWATCH: First-quarter moon, Sunday, Dec. 28. Tonight, Wednesday, Dec. 24, a very slim crescent moon will be just to the right of Mars.

NEXT WEEK: More astronomical blathering.

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