Fuzzy Stuff in Space
copyright: David Carpenter 2001

My basic approach to astronomy is to teach things in the order you would teach someone in your backyard with a telescope. Then, perhaps, the student who happens to own or is about to buy a telescope, will have success in using it. At the same time, the student will learn something about the objects he or she is looking at, and gain a realistic perspective of the universe around them.

What can you see with a small telescope?

• Mountains and craters on the moon.
• The four largest moons of Jupiter and some banding.
• The rings of Saturn (you can see that it has rings, probably no detail).
• The phases of Venus
• A polar cap on Mars (if you're very fortunate and observing when Mars is closest to Earth).
• Sunspots and granulation on the sun (with eyepiece projection or other safe method, of course). Never look directly at the sun. It can instantly and permanently damage your eye.
• The Milky Way resolved into countless faint stars.
• Fuzzy Stuff in Space

Comets:     "Dirty Snowballs, a few kilometers in diameter, in orbit around our star, the sun. They are fuzzy because solar radiation causes the ice to sublimate, creating a fuzzy halo around them. Often the solar wind blows the 'refuse' behind the comet forming one or more fuzzy tails.  When a comet's orbit brings it close to us, they can sometimes be seen with the unaided eye.

Nebula:     Clouds of gas in space between and around stars. Some are lit brightly by stars in front of them, some are seen in silhouette because they block background stars and bright nebula. Some are forming new stars and some are the exploded remains of old stars.  The easiest to see is the Great Nebula of Orion in Orion's sword.

Galaxies:    A group of billions and billions of stars, all orbiting their common center of gravity.  Our galaxy, the Milky Way, is pinwheel shaped, and about 100,000 light years in diameter.  This is about 100,000,000 times bigger than our solar system, out to the orbit of Neptune.   Many galaxies have a black hole at the center.  Ours, the Milky Way,  has a black hole with the mass of about a million suns.  The easiest galaxies to see from the southern hemisphere are two dwarf satellite galaxies of the Milky Way, the Magellanic Clouds.  From the northern hemisphere, the Andromeda Galaxy (see image below) is the closest, largest, and easiest to see.  Our galaxy, the Milky Way, looks like a large band across the sky instead of a spiral or pinwheel because we are looking at it from the inside out.

Open Clusters:     A group of several to hundreds of stars, gravitationally bound together, within the spiral arm of a galaxy.  These stars form out of a common nebula, and remnants of that nebula can often be seen around the star.  These systems are unstable, and eventually sling their stars out into individual orbits in the galaxy.  Open Clusters can be thought of as stellar nurseries.  The easiest to see is the Pleiades in the constellation Taurus (in front of Orion).

Globular Clusters:    A round or globular (shaped like a globe) cluster of millions of stars, in orbit around a large galaxy.  The Milky Way and Andromeda galaxies have hundreds of these orbiting closely around them.  The easiest to see is M13 in the constellation of Hercules.

The best place to look for "Fuzzy Stuff" is in and around the constellation of Sagittarius.  Sagittarius can be found by following the Milky Way southward from the Northern Cross.  Sagittarius looks like a teapot.  Sweeping this area with binoculars or a wide field telescope [from a location without street lights] will bring lots of "Fuzzy Stuff" into view.

copyright: David Carpenter 2001