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Moon Phase Calendars: 2004-2010 / Moon Calendar / Moon Phase Now (or for any other date)
Earth-Moon Viewer / New Moon-Full Moon Dates
Online Lunar Atlas / Consolidated Lunar Atlas / Lunation Animation

The moon's phase is important for observers. It tells you when the moon will appear in the sky and how bright it will be. If you want to look at faint galaxies or nebulae with a telescope, it is best to observe when the moon is not in the sky, so a Moon Phase Calendar is useful for planning observing trips. If, on the other hand, you want to look at the moon itself, the phase of the moon determines what will be visible. When you want to look at the moon with a telescope or binoculars, the part of the moon along the terminator (the line dividing the dark and light sides) is where the craters show up best because that's where they cast the longest shadows. Read the article with the first link above for more information and yearly moon calendars you can print out.

The Planets

Planet Locator: 2004-2010 / Planet Tracker / The Solar System Live /
The Planet Finder / Jupiter's Moons / The Nine Planets

Planets cannot be included on printed star maps because they move. Furthermore, since both the planets and our observing platform (the earth) are moving, the apparent motions are quite complex. It's rather like watching people strolling through the part from the point of view of a merry-go-round.

The planets are visible in some detail in even small telescopes. Even Binoculars will show the moons of Jupiter. Almost any astronomical telescope will show the rings of Saturn, the phases of Venus, and the polar caps and subtle dark markings on Mars (when Mars is closest to the earth, near opposition).

Comets

Gary Kronk's Comet &Meteor Home Page / IAU/CBAT Comet Elements in Deep Space Format

Comets are dirty icebergs floating through space. They can become spectacular when they pass near the sun and their outer layers evaporate (technically "sublime"), forming a temporary atmosphere (the coma) which can blow away as a tail driven outward from the sun by solar radiation and the solar wind. Most comets are only visible when they are near the sun, so they must be discovered, charted, and followed on an unannounced schedule. If you are interested in comet observation you really need software to chart the paths. Deep Space, even though it is a DOS progam dating from the mid 1980's, has some of the best comet-oriented features of any software for amateurs. Most other planetarium programs have comet-related features as well.

Meteor Showers

Gary Kronk's Comet &Meteor Home Page

Meteors are bits of debris floating through space that hit the earth's atmosphere (typically at about 90,000 miles per hour!) and burn brightly as they dissipate their energy in a brief flash. A 1-gram meteor 100 miles high, at the top of the atmosphere, can glow with about a million watts of light, making it bright enough to be seen from earth! Large meteors are typically fragments of asteroids, but the tiny ones are more commonly associated with comets that leave their litter in orbital streams. When the earth passes through a meteor stream all the particles are moving in parallel. Our perspective as we watch them come toward us, makes them appear to radiate from a single point in the sky. These streams of meteors are called meteor showers. The earth cycles through them at predictable intervals. Some of the larger showers can produce hundreds of meteors per hour. Occasionally a meteor storm can bring in hundreds per minute!

Eclipses

Eclipse Home Page / The Exploratorium Eclipse Site / Solar Eclipse Eye Safety / Observing Techniques

A total eclipse of the sun is a wonderful, beautiful, exciting event. Other eclipses are merely interesting, by comparison, but they can be quite interesting if you know how to observe them and what to look for. Developing a taste for "eclipse chasing" will make a world traveler out of you. Many people do it as a way to see parts of the world they would otherwise pass by. Learn to observe eclipses safely, and enjoy.

The Constellations

Stories of the Constellations / Hawaiian Astronomical Society / Astronomy and Vedic Culture

Amateur astronomers use the constellations at tools: they are stepping stones to finding where to point their telescopes. Constellations have a long history, however, and many of them have become associated with stories and myths in various cultures--not just ancient Greece and Mesopotamia. To learn the constellations you need a star map that accounts for the rotation of the earth and its orbit around the sun: a planisphere. The Night Sky is an improved planisphere specially designed to minimize distortion.

Deep Sky Observing

Observing Log Master Sheet / The Messier Catalog / Deep Sky Image Archives

Deep sky observing (observing objects beyond our solar system) is generally the domain of larger telescopes, but an amazing amount can be seen with the unaided eye and/or a simple pair of binoculars under dark sky conditions. Our own Exploring the Night Sky with Binoculars and Sky Atlas for Small Telescopes and Binoculars are good starters for deep sky observing. Once you get into using a telescope you will want one or more planetarium programs such as Deep Space.

Dark Sky Activism

International Darksky Association

When it comes to seeing "faint fuzzies", or even appreciating the beauty of the universe, darkness is the key! That means no moon, but also no street lights, no nearby city lights. The sky would be MUCH darker if we had the same amount of outdoor lighting as today but it was all shielded with the light directed downward. You don't light your living room with bare bulbs, you don't like people coming at you with high beams on, why should we have to tolerate mercury vapor lamps everywhere with the light shining directly into our eyes (glare) and a large percentage of it ending up as wasted energy that pollutes our skies? Shielded lighting makes sense for everyone!

Satellites

Heavens Above

You can see satellites any night you look for them. To see them you must be in twilight or dark and the satellite must be in direct sunlight. That means they are best seen shortly after sunset or before sunrise. Look for polar orbiters moving north or south. These satellites are looking down. They map out a different strip of the earth on each pass. Those not looking down generally orbit from west to east, since the eastward rotation of the earth gives them a boost in that direction upon launch. Certain satellites have large solar panels that reflect sunlight like mirrors and will appear to flash occasionally. The Heavens Above web site does a wonderful job of keeping you up to date with what we have put into the sky.

Breaking News

The Universe Today / Astronomical Picture of the Day (APOD)

"Astronomical Picture of the Day" sounds like a trivial site, but it is far from it! The site is one of the best astronomical educational resources on the Internet. Each day they bring you a beautiful and interesting tidbit of astronomy, often in the breaking news category, but always something that will amaze you, together with a short paragraph of explanation and dozens of links to background on various technical levels. The archive for this site is HUGE: a picture/article per day dating from June, 1995. For several years I practically taught my astronomy courses around pictures from this site. You might consider making it your home page!

General Information

Sky Online - Home Page / Hubble Space Telescope Public Information / Jack Horkheimer Star Gazer Page

Astronomy on the Internet is huge. There used to be sites with huge link collections, but Google has become the ultimate site collection. While you're at it, don't forget to turn off your computer and go outside and look up.