Beginning to Observe The Solar System

The Solar System, including the good old Moon, has its charms. On any evening a bright planet over the horizon is impossible not to send the scope to. Even if Solar System work isn't to be a mainstay of the hobby, it's still fun and can let a new telescope prove its mettle. A look at the Moon and planets with the new SCT will also prove once and for all that the "experts" down at the club and on the Internet who say SCTs are "no good" for planets are wrong. Yes, the SCT has a large central obstruction. No, that doesn't stop it from doing a terrific job on the Solar System.

The Moon What better first light subject for a CAT is there than Earth's faithful companion, Luna? Deep sky fans may disagree, but lucky is the amateur who's fortunate enough to find a nice crescent or gibbous Moonhanging in the sky on a first light evening (a full Moon doesn't reveal many details due to the high Sun angle).

Ready to begin a voyage of discovery? Point the CAT at the wonderful Moon. Once the go-to scope stops go-toing or a manual telescope's finder is centered on Earth's satellite, put an eye to the eyepiece. You'll probably be half-blinded at first. The Moon is bright in an 8-inch or larger scope at low power. Some beginners are struck by how bright Luna is through the telescope and wonder if this intense light might be harmful. Don't be concerned. At a magnitude of -12.7, the Moon is roughly 400,000 times dimmer than the magnitude -26.7 Sun. Luna's silvery light is not anywhere near intense enough to damage eyesight. Actually, the Moon's surface, despite what poets say, is not "silver"; it is a color similar to fresh asphalt; it looks bright at low power but really isn't.

Once they are over the shock of the Moon's brightness, most new astronomers are overwhelmed at the incredible wealth of detail a telescope is capable of revealing on this ancient relic of a world. Your telescope should reveal a wealth of details. If the image of the Moon in the CAT doesn't appear crystal clear, adjust the focus control until it is as sharp as possible. Focus by observing the craters and mountains that stand out in stark relief along the Moon's day/night terminator line. And then just look for a while. Use the hand controller to keep the Moon centered if necessary (with good telescope alignments adjustments should only be needed occasionally) and to scan up and down the terminator line.

When Luna has been examined at low power, switch to a shorter focal length eyepiece. Higher magnification makes the image dimmer, but many more fine details are revealed, especially on the day-night line. Not only are there craters, there are craters within craters. Seeing the smallest details available to even a small scope requires plenty of power. How much power? Continue to increase magnification until you can't see any additional detail. At some point more power won't show anything more. The image will get fuzzier as well as bigger because of unsteadiness in Earth's atmosphere, too little telescope aperture, not enough optical quality, or poor collimation of the telescope's optical system. Magnification that doesn't produce more detail is referred to as "empty magnification." It's not at all unusual, however, to have to use powers of 300x and more on the Moon with an 8-inch. Despite what those strait-laced "experts" at the club may have said about high power, high magnification does have its place; especially in lunar and planetary observing.

Lunar Features

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