shadows fall on the craters and canyon walls to give them defi- nition. While the full moon may look like a tempting target, it is not optimal for viewing! The light is too bright and surface definition is low.
Even at partial phases the Moon is very bright. Use of an optional Moon filter to helps to dim the glare. It simply threads onto the bottom of the eyepiece. You’ll find the Moon filter improves viewing comfort, and helps bring out the subtle fea- tures of the lunar surface.
B. The Sun
You can change your nighttime telescope into a daytime Sun viewer by installing an optional full-aperture solar filter over the front opening of the telescope. The primary attraction is sun- spots, which change shape, appearance, and location daily. Sunspots are directly related to magnetic activity in the Sun. Many observers like to make drawings of sunspots to monitor how the Sun is changing from day to day.
Important Note: Do not look at the Sun with any optical instrument without a professionally made solar filter, or permanent eye damage could result. Also, be sure to cover the finder scope, or better yet, remove it altogether.
C. The Planets
The planets don’t stay put like the stars, so to find them you should refer to the Learning Center at our website telescope. com and choose “In the Sky”, or to charts published monthly in Astronomy, Sky & Telescope, or other astronomy magazines. Venus, Mars, Jupiter, and Saturn are the brightest objects in the sky after the Sun and the Moon. Your SkyQuest XT is capable of showing you these planets in some detail. Other planets may be visible but will likely appear starlike. Because planets are quite small in apparent size, optional higher power eyepieces are recommended and often needed for detailed observations. Not all the planets are generally visible at any one time.
JUPITER The largest planet, Jupiter, is a great subject for observation. You can see the disk of the giant planet and watch the ever-changing positions of its four largest moon: Io, Callisto, Europa, and Ganymede. Higher power eyepieces should bring out the cloud bands on the planet’s disk and the Great Red Spot.
SATURN The ringed planet is a breathtaking sight. The tilt angle of the rings varies over a period of many years; some- times they are seen edge-on, while at other times they are broadside and look like giant “ears” on each side of Saturn’s disk. A steady atmosphere (good seeing) is necessary for a good view. Look closely and you should see the Cassini divi- sion, a thin, dark gap in the rings. You should also see one or more of Saturn’s moons, which look like faint stars. The bright- est is the moon Titan.
VENUS At its brightest, Venus is the most luminous object in the sky, excluding the Sun and the Moon. It is so bright that sometimes it is visible to the naked eye during full daylight! Ironically, Venus appears as a thin crescent, not a full disk, when at its peak brightness. Because it is so close to the Sun, it never wanders too far from the morning or evening horizon.
No surface markings can be seen on Venus, which is always shrouded in dense clouds.
MARS The Red Planet makes a close approach to Earth every two years. Observing Mars is most favorable at these times. You should see salmon-colored disk with some distinct dark patches, and you may be able to spot a whitish polar ice cap. To see surface detail on Mars, you will need a high power eyepiece and very steady air!
D. The Stars
Stars will appear as tiny points of light. Even powerful tele- scopes cannot magnify stars to appear as anything more than pinpoints. You can, however, enjoy the different colors of the stars and locate many pretty double and multiple stars. The famous “Double-Double” in the constellation Lyra and the gor- geous two-color double star Albireo in Cygnus are favorites. Defocusing a star slightly can help bring out its color.
E. Deep-Sky Objects
Under dark skies, you can observe a wealth of fascinating deep-sky objects; that is, objects that reside outside of our solar system. These include gaseous nebulas, open and globular star clusters, and a variety of different types of gal- axies. The large apertures of SkyQuest XT Dobsonians are particularly well suited to gathering light, which is critical for observing these usually faint celestial entities. For deep-sky observing it is important that you find an observing site well away from light pollution. Take plenty of time to let your eyes adjust to the darkness. As you become more experienced and your observing skills get sharper, you will be able to ferret out more and more subtle details and structure from these fasci- nating objects. Do not expect to see color in deep-sky objects, however, as human eyes are not sensitive to color from faint light.
How to Find Deep-sky Objects: Starhopping
Starhopping, as it is called by astronomers, is perhaps the simplest way to hunt down objects to view in the night sky. It entails first pointing the telescope at a star close to the object you wish to observe, and then progressing to other stars closer and closer to the object until it is in the field of view of the eyepiece. It is a very intuitive technique that has been employed for hundreds of years by professional and amateur astronomers alike. Keep in mind, as with any new task, that starhopping may seem challenging at first, but will become easier over time and with practice.
To starhop, only a minimal amount of additional equipment is necessary. A star chart or atlas that shows stars to at least magnitude 5 is required. Select one that shows the positions of many deep-sky objects, so you will have a lot of options to choose from. If you do not know the positions of the constel- lations in the night sky, you will need to get a planisphere to identify them.
Start by choosing bright objects to view. The brightness of an object is measured by its visual magnitude; the brighter an object, the lower its magnitude. Choose an object with a visual magnitude of 9 or lower. Many beginners start with the Messier objects, which represent some of the best and bright-
