Star Bright

One of my favorite sports is to lie back in the outdoor tub and star gaze. (The body is disengaged, while the mind goes into overdrive.) As my eyes adjust to the darkness I can see dimmer and dimmer stars—the star count dramatically increases. This is especially true for those dim stars not directly in my central vision. (The peripheral rods in the eye’s retina are more light sensitive than central-vision cones. So, if you don’t look exactly at a dim object, you can actually see it better.)

I love to notice dim peripheral stars—ones that I’d otherwise miss—and wonder how far off they might be, what planets might be circling them, or what their corner of the galaxy might look like.

I’m also aware that my naked eye can see but a tiny fraction of the stars whose light reaches Earth. Only the closest, brightest stars can I observe. From the most dazzling star in our sky—Sirius—to the dimmest, my eye can detect a very limited range. I can make out stars whose light is 250 times fainter than Sirius, and that’s it. All the billions and billions of dimmer stars and galaxies, I am forever banned from detecting—that is, without peering through some mechanical magnifying aid.

That’s why Galileo and his buddies were so thrilled when the telescope was invented. Suddenly, oodles of more stars could be seen (as well as the moons of Jupiter and other celestial delights). A small telescope, for example, will allow me to see stars that are 50 times dimmer than what the naked eye can make out. Even a modest pair of binoculars will let me see 25 times better.

Years ago I bought an 8-inch scope. It allows me to see 600 times better! Oh, if only I had one of those giant scopes they build on mountain tops in my backyard; I could see stars that are over a billion times fainter than the naked eye! And what can the Hubble Telescope see? Too much!

(Just to play with the numbers a little more—and going the other way, to brighter objects in the firmament: The brighter planets—Venus, Mars, Jupiter—are about 15 times more vivid than Sirius. The full moon? It’s 30 thousand times brighter. And going to the ultimate, our own Sol is 17 billion times brighter than Sirius! Of course, that’s just how we see it, since it’s a whole lot closer.)

While gazing at those stars—with naked eye and body—in the tub, I may not be able to see much, compared to those big scopes, but my imagination isn’t hindered. I’m immensely thankful for what Hubble and all those wonderful scopes show me, but for the current tub-soaking moment, the small selection of dim points of light are amazing enough.