Astronomy - USA (2020-01)

18 ASTRONOMY • JANUARY 2020

STRANGE UNIVERSE

“Which is better, a 3-inch refractor or 6-inch

ref lector?” That’s the kind of issue debated on

astronomy forums.

Oddly enough, this page has never offered equipment

advice. Let’s do it now. But before I pretend to be an

authority, let me brief ly explain my background. It has

a familiar beginning: I became an enthusiastic observer

at age 12, thanks to a 60mm refractor I received for

Christmas. My obsession drove me to memo-

rize every star that had a name or Greek let-

ter, along with their distances and spectral

classes. Studying astronomy at a university

provided sufficient credentials to teach astro-

physics at Marymount Manhattan College in

New York City, even though I’d never earned

a doctorate.

Nor did I ever grind a single telescope mir-

ror. Nonet hele s s , opt ic s so fa sc i nated me t hat

when the cranky old telescope maker John

Dobson came to be my houseguest 15 years

ago, it was unforgettable. Not only did he show me a

quick way to collimate my primary mirror, he also

regaled me with boasts about his lifetime of poverty.

What are my credentials? I own all three basic tele-

scope types. I have an original Celestron sandcast C

and a beloved C5 that is truly portable and tracks the

stars while powered only by a 9-volt battery. In 1982, I

built a 12-by-18-foot (3.7 by 5.5 meters) motorized roll-

off-roof observatory to house my new Meade research-

grade 12.5-inch f/6 ref lector. Its rotating tube on

bearings was one of the universe’s great ideas, because

it allowed the user to position the eyepiece at any con-

venient location. Gone were the times when you’d have

to possess wings and somehow be positioned above the

instrument, 8 feet (2.4 m) above the ground, to look

through it. I still use that observatory today.

When I acquired a 5-inch Takahashi refractor, I first

piggybacked it on the 12.5-incher. But after moving to

a darker location in 1998, I put up a second observatory

near my home, this one with a dome. I loved the original

observatory’s roll-off-roof design, but there’s something

undeniably cool about a dome.

So cool, in fact, that in recent years, several compa-

nies have offered domes at affordable prices. I chose an

Explora-Dome 10-by-10-foot (3 by 3 m) metal building

with an 8-foot (2.4 m) motorized dome, inside which I

installed the Takahashi apochromat on a bulletproof

Te m m a m o u nt.

It’s hard to get used to looking through a slit and see-

ing just a little slice of sky, so I still think the roll-off is

the best way to go. Nonetheless, the dome works great. If

you do buy one, it’s cheapest to assemble it yourself. But

as someone who loathes putting together Ikea furniture,

I thought the company’s offer to send two guys to do all

the assembling for a mere $600 was the best deal ever.

So, based on my half-century of experience with

scopes and places to use them, which type of telescope is

best? Spoiler alert: You’ve heard all this before. If you

need to carry it to a dark site, it’s hard to beat a Schmidt–

Cassegrain for portability. If you want the obvious ben-

efits of large aperture, then Newtonian ref lectors deliver

the biggest bang. If you’re a lunar and planetary aficio-

nado and have the money, then the latest crop of apo-

chromatic refractors is amazing. Plus, they

can give ultra-low-power views of deep-space

objects so you can get the entire Andromeda

Galaxy, Pleiades, or Double Cluster in Perseus

in a single field, a wonderful experience.

The old cliché is still true: No one tele-

scope type can confer every advantage. Being

in the astro-realm means living in a compro-

mise dimension. This trade-off is epitomized

for those living in a bright city, where a pri-

vate observatory can be a distant dream.

So, consider living under dark skies from

the get-go. Rural areas need teachers, nurses, and tax

accountants. Granted, the pizza will probably be bad.

Where I live, there is no mail delivery or cell service.

And forget nightlife. But in truly rural regions, your

backyard routinely hosts a thrilling Milky Way.

And in such places, the wordy debates about equip-

ment largely vanish, silently dissolving into the overhead

star clouds.

A good sky can put an end to the great telescope debate.

Invitation to the

Dark Side

The author in his roll-

off-roof observatory.

A 5-inch refractor

rides piggyback on a

12.5-inch f/6 reflector.

BOB BERMAN

The old

cliché is still

true: No one

telescope

type can

confer every

advantage.

BY BOB BERMAN

Join me and Pulse

of the Planet’s

Jim Metzner

in my podcast,

Astounding Universe,

at http://www.astounding

universe.com

BROWSE THE “STRANGE UNIVERSE” ARCHIVE

AT http://www.Astronomy.com/Berman