Share This Page

Shooting star pollution sharpens telescope snapshots

| Saturday, Aug. 10, 2013, 9:45 p.m.

As skywatchers marvel at the beauty of the annual Perseid meteor shower — set to peak late Sunday and early Monday — astronomers will be thanking their shooting stars for another reason. Airborne pollution from vaporized meteors is proving crucial for the next generation of super-sharp snapshots of exotic moons and distant galaxies.

Pollution of any kind is usually bad news for telescopes, which thrive on clear skies. But shooting stars — flaming bits of debris from comets — leave traces of an element astronomers are harnessing to sharpen the focus of their telescopes.

That element is sodium. Traces of it waft in a band encircling the Earth about 55 miles above ground. American astronomer Vesto Slipher of Arizona discovered this sodium layer in 1929, but only recently have astronomers found a use for it — by zapping it with lasers.

Sensors watching these artificial “guidestars” see them twinkle — the effect of atmospheric turbulence. By watching the guidestar, sophisticated computers on the ground can calculate the turbulence and send that data to the telescope. Sophisticated mirrors in the telescope then deform hundreds of times per second to compensate for the wavy air.

It's like adding a pair of glasses with rapidly changing prescriptions to the telescope.

TribLIVE commenting policy

You are solely responsible for your comments and by using TribLive.com you agree to our Terms of Service.

We moderate comments. Our goal is to provide substantive commentary for a general readership. By screening submissions, we provide a space where readers can share intelligent and informed commentary that enhances the quality of our news and information.

While most comments will be posted if they are on-topic and not abusive, moderating decisions are subjective. We will make them as carefully and consistently as we can. Because of the volume of reader comments, we cannot review individual moderation decisions with readers.

We value thoughtful comments representing a range of views that make their point quickly and politely. We make an effort to protect discussions from repeated comments either by the same reader or different readers

We follow the same standards for taste as the daily newspaper. A few things we won't tolerate: personal attacks, obscenity, vulgarity, profanity (including expletives and letters followed by dashes), commercial promotion, impersonations, incoherence, proselytizing and SHOUTING. Don't include URLs to Web sites.

We do not edit comments. They are either approved or deleted. We reserve the right to edit a comment that is quoted or excerpted in an article. In this case, we may fix spelling and punctuation.

We welcome strong opinions and criticism of our work, but we don't want comments to become bogged down with discussions of our policies and we will moderate accordingly.

We appreciate it when readers and people quoted in articles or blog posts point out errors of fact or emphasis and will investigate all assertions. But these suggestions should be sent via e-mail. To avoid distracting other readers, we won't publish comments that suggest a correction. Instead, corrections will be made in a blog post or in an article.