Much of the time, astronomical observing involves
straining to perceive something at the limit of detectability, such as a
faint galaxy, a dim double-star companion, or a tiny festoon in
Jupiter’s clouds. The more you look the more you see, so the key to
really enjoying backyard astronomy is to spend lots of time doing it. It
also helps if you take the trouble to learn as much as you can about
what you’re looking for, because even when you find it you may not be
terribly impressed with the view. As I’ve written before (S&T:
January 2005, page 8), most celestial objects are small, faint, or both,
so they’re best appreciated with the mind rather than the eye.
Among the relatively few exceptions to this rule, the
most extreme is a total eclipse of the Sun. You don’t have to use
averted vision or special filters or other tricks to experience
totality. You just have to put yourself in the right place at the right
time and hope for clear skies. When the Moon’s shadow arrives, it hits
you over the head — big time!
I like to use the phrase "experience totality" rather than "see
totality," because a total solar eclipse is the only celestial
phenomenon I can think of that truly overwhelms the senses, so much so
that it’s virtually impossible for a single observer to take in
everything that happens. You can’t look up in the sky at the last sliver
of Sun at the same time you’re looking down at the ground for shadow
bands. You can’t admire the pretty sunset colors around the horizon or
scan the sky for bright stars and planets while you’re examining coronal
streamers in your telescope. And you can’t watch the "diamond ring"
glitter at the end of totality while you’re using a diffraction grating
to watch for chromospheric emission lines to flash into view.
So you end up seeing some things that others miss, and missing some
things that others see. But you also feel the eclipse, as the
temperature drops and the wind changes. And you hear it, too, when you
and your fellow eclipse-chasers holler with excitement as the event
unfolds. (In Mexico in 1991 and in the Caribbean in 1998, observers
enjoyed the taste of totality too, thanks to Corona beer and Eclipse
Barbados rum!)
I experienced my sixth total eclipse last March 29th in the Libyan
desert, with a sizable Sky & Telescope/TravelQuest International
tour group that had sailed to Libya from Italy aboard the MSC
Sinfonia. Afterward, as we shared with each other what we saw,
heard, and felt, I realized that this eclipse had featured almost every
phenomenon I’d ever heard of in connection with totality — though as
usual I hadn’t seen every one of them myself. About the only thing
missing was a surprise sungrazing comet.
If you’ve never experienced totality but spend your clear nights
straining at the eyepiece to check off faint fuzzies on the Messier,
Caldwell, or Hershel lists, I urge you to think about traveling to
totality at the next opportunity. You really owe it to yourself to check
off the one celestial target that eclipses all others.