How to Use the Sky Calendar.

Whether you are a beginning or experienced skywatcher, the Sky Calendar can enhance your observing skills and increase your awareness of the wide variety of changes in the sky. Refer to this calendar daily, and you'll soon find yourself tracking the Moon's rapid day-to-day motion past planets and bright stars, and following the more leisurely pace of planets.

Each daily calendar illustration includes two essential pieces of information: The time of night to observe the sky, and the direction to look.

In most of the dayboxes, the time given is dusk or dawn. The illustrations designated "dusk" show the sky nearly midway through twilight, the interval of gradually decreasing light which follows sunset. Dusk as used on this calendar means about 40 to 55 minutes after sunset from mid-U.S., depending on the time of year. (Longest twilight comes in June, shortest in March and in September-October.) The illustrations designated "dawn" show the sky a similar interval ahead of sunrise.

Some of the dayboxes are for other times, for example: Two hours after sunset; or 30 minutes before sunrise.

A square day-box with a landscape along its lower edge shows the sky from the horizon up to more than one-quarter of the way toward overhead. An illustration without a landscape shows a section of sky farther above the horizon.

As you attempt to observe the Moon daily at dusk or dawn, you'll very often spot it near one of the five bright planets (Mercury, Venus, Mars, Jupiter, or Saturn), or near one of several bright stars or noteworthy star patterns in the zodiac: the Pleiades, Hyades, or Aldebaran in Taurus; Castor and Pollux in Gemini; Regulus in Leo; Spica in Virgo; Antares in Scorpius; and the Teapot in Sagittarius.

As you follow the planets, you'll notice they occasionally pass one another, as well as the same zodiacal stars the Moon does.

The Moon or any of the brightest planets (Venus, Jupiter, and, occasionally Mars) can serve as a useful guide to objects of lesser brightness shown in the same diagram. At the date and time indicated in the day box, face the appropriate direction, and compare the illustration to what you see in the sky.

Most events depicted in the dayboxes are visible to the unaided eye. Binoculars often enhance the view, or may be needed in certain situations:

Remember: If you observe the sky later than the prescribed time of an evening event, the sky may get darker, but objects low in the west will be even lower and may set. In the east, objects will get higher as time passes. If it is morning, the sky will get brighter as sunrise approaches.

Also, remember to check the calendar at least one day ahead, so you won't miss any spectacular morning events!

Additional information on viewing the planets appears in the left margin of each month's calendar.