SKY TALK – APRIL 2018
Small Telescope Astronomy
Today’s mantra that “bigger is better” when it comes to TV screens, cars, houses, stadiums, etc. definitely doesn’t apply to telescopes for stargazing. Turns out that small scopes have some important advantages over larger ones and, surprisingly, in many cases can provide views of celestial wonders unmatched by the biggest of instruments!
Let’s begin by considering some of the advantages small telescopes have over large ones. They are highly portable—no lugging heavy equipment out and back in for observing. Also, they essentially ready for instant use—no long cool-down time for the optics to adjust to the night air. And they are less sensitive to atmospheric disturbances which often plague bigger scopes. Now let’s look at some of the wonders small glasses offer.
First and foremost is the Moon. Those who have ever only looked at our lovely satellite close-up with high magnifications are surprised at its crystalline appearance seen at low power, which frames the entire Moon. Total and partial lunar eclipses are at their absolute best in small scopes, which bridge the gap between typical big telescope and binocular views. And for a real thrill, there are the occultations of other sky targets—especially one of the planets, a bright star, or a big cluster like the Pleiades. The Moon literally appears suspended three-dimensionally in space as it glides across the latter of these, covering and then uncovering the cluster’s stars in its eastward orbital motion.
Next are the brighter planets, several of which look positively jewel-like at the low magnifications small scopes make possible. Venus, when in its crescent phase a few weeks before and after inferior conjunction, is one example—a tiny, radiant silver sliver hanging in the sky. Jupiter attended by its four Galilean satellites surely has to be one of the most thrilling sights in the heavens. The endless dance of its tiny moons about the planet, continually changing position and configuration, never loses its fascination. And then there’s Saturn—the supernal wonder of celestial wonders, the iconic image of astronomy, the most other-worldly-looking object in the heaven! The spectacle of the rings hugging the planet, just resolved at low powers, looks too beautiful and ethereal to possibly be real!
Beyond our solar system are glories for the smallest of telescopes without number. These include fiery pulsating variable stars, colorful double and multiple suns, glittering stellar jewel-boxes and beehives, eerie glowing stellar nurseries where new stars are being born, remote galaxies far beyond our own, and the awesome Milky Way in which we live.
— James Mullaney
Former assistant editor at Sky & Telescope magazine & author of nine books on stargazing. His latest, Celebrating the Universe!, is available from HayHouse.com.