What’s Up This Fourth Week of December

This week sunset will occur around 5:15 PM and the first stars will star appearing about an hour after that. However, the weather this week is very typical of the Ohio winter – cloudy, wet, and cold. There is a chance that the clouds will disappear over the weekend. The nighttime temperatures this time of year drop into the 20’s and 30’s, so be sure to dress warm when you’re outside stargazing. This week brings us the finale of the Great Conjunction, the peak of the Ursids meteor shower, the moon near Mars, and since Christmas is here – a few tips for setting up a telescope for its first light under the stars.

If you have not heard already, the Great Conjunction of Jupiter and Saturn occured on Monday. While this is the closest these two outer planets have appeared in the sky in several hundreds of years, do not worry if you miss it (thank you, cloudy Ohio skies). These planets will slowly drift further apart in the sky and there is a large window of several days, even weeks, where these planets will still appear to be very close to each other. This conjunction also occurs every 20 years, although these two planets may not appear to be as close as this recent conjunction.

Image taken on December 19 by friend of JGAP, Robert Sparks… not in Ohio (of course.)

Tuesday marks the peak of the Ursids meteor shower. This shower will only yield roughly ten meteors per hour under dark skies. These fireballs can typically be seen between December 17th and December 26th and will appear to originate from the Ursa Minor constellation. Ursa Minor, not to be confused with the more famous, Ursa Major, otherwise known as the Big Dipper, is very close to the North Star. From Ohio, the North Star and Ursa Minor star can be found by looking due North and looking up about 40° (four fists held at arm’s length) above the horizon.

The “radiant” of the Ursid meteor shower is in, of course Ursa Major. This is the point in the sky from which the stars appear to emanate.

On Wednesday try spotting the bright waxing gibbous moon in the southern skies. You may notice a bright red-colored star nearby. This bright star is in fact the red planet Mars. A pair of binoculars or a telescope will reveal lots of surface detail on the moon. A telescope with a long enough focal length and high power eyepiece may even be able to resolve the Martian ice caps!

With Christmas this Friday, many of you may be receiving or gifting others a brand new telescope or astro-equipment. While it may be irresistible to take the new telescope outside that night and begin using it, there are a few things to check and perform so that the telescope is operating at its maximum potential and will give the least frustration. There are two different main types of telescopes: reflectors and refractors (yes, some telescopes combine these two designs). There are also different mount styles, alt-az and German equatorials being the most common. Most refracting telescopes (use glass lenses) are ready to go right out of the box. Reflecting telescopes (designs that use a mirror) may require a check of the collimation since the mirrors may be slightly misaligned. There are many beginner’s guides to collimation online. For the mounts, alt-az (short for altitude and azimuth) mounts are very common and simple to use. Electronic alt-az mounts usually only require a few alignment stars to get the computer oriented to the night sky. German equatorial mounts are a little more advanced and expensive but have a many advantages. These mounts require knowing your local latitude and having a compass or sight of the North Star to start getting it oriented to the night sky.

Some advice from past experience – always get familiar with your equipment inside before setting things up in the frigid temperatures or after nightfall. New or unfamiliar equipment may have a bit of an unforeseen learning curve or troubleshooting that may eat up your time outside.

While Ohio seems to have some poor weather, the end of the week may surprise us all. Be prepared to dress warm while outside looking at the finally of the Great Conjunction, some Ursids meteors, the moon and Mars, or trying out some new astronomy gear. Since the solstice was Monday, the nights will slowly get shorter and shorter so be sure to take full advantage now of the long nights.

Clear Skies!

Jared May: What's Up, December 22-28