View Full Version : Reading with starlight

2004-Dec-01, 07:22 AM
On the bad astronomy website, one of the common misconceptions is that you can see stuff solely under staarlight. In a recent Sky & Telescope issue, I read that they found out that the Milky Way creates a shadow. Wouldn't this be enough light to read?


2004-Dec-01, 07:38 AM
i tried it under what you might call ideal circumstances (deep in the Australian Outback, moonless night, no light polution from other sources) and the answer is no.

i just couldn't make out the words. you can see there's text on the page and that it's made up of indicidual words, but you can't read them. it's a very strange thing, especially since you can see your surroundings quite clearly.

2004-Dec-01, 07:43 AM
At the Mt. Kobau Star Party two years ago in southern BC under very darks skies I was suprised. Conditions were excellent except for a strong wind which toppled one fellow's telescope and smashed an expensive reticle eyepiece he had just purchased and installed before he had a chance to even look through it. But I digress. This was in late August with the Milky Way as high as it ever gets in our sky. We (my friend and I) were somewhat suprised by the fact that we could quite easily see to walk around our observing site without the aid of our red LED flashlights. That night I spoke to the director of the Arizona State Observatory and he told me than on one occasion when observing from a southern location below the equator the Milky Way was bright enough to cast a shadow over his shoulder and bright enough to just barely read by. It's not an urban legend if you have the opportunity to go far enough south.

2004-Dec-01, 07:50 AM
I don't know. Never bothered to try. Guessing, the below agrees, surely some font-size would be readable. A good long dark adaptation would, of course, help.

One site (http://www.astropix.com/HTML/L_STORY/SKYBRITE.HTM) sez:

Is it possible to read by starlight or the Milky Way?

You can read newspaper headline type (not just huge disaster banners, but small headlines). Roach and Gordon talk about this in the "Light of the Night Sky" book. The classic Sky and Telescope article by Roach and Jamnick "The Sky and the Eye" (Sky and Telescope, vol 17, February 1956, page 165) about the night sky mentions this, too. I don't know what the small limit is, and I'm not sure it would be terribly relevant to astronomical viewing.

By the way, here (http://www.badastronomy.com/bad/misc/badstarlight.html) is the BA's reasoned take on it.