Heads Up, Skywatchers! Venus Transit

Science Tech


This is a do-not-miss event! This is the last time Venus will cross the face of the sun for 105 years. Why does this happen so rarely? It’s because Venus’s orbit is slightly tilted from earth’s. So usually, it passes above or below the sun.

This event is a pretty popular topic on the internet, so I guess I’ll add my share. First a word of caution: Don’t look at the sun. It’s pretty obvious, but still… it can fry your eye’s retina. There are several ways to safely view this event, though.

Eclipse Shades: these are very inexpensive solar filters that are worn like glasses.

Telescope Projection: if you have a decent quality telescope, you can use it to project and image of the sun on a piece of paper. Don’t look through the telescope, though! And don’t look through the finderscope; in fact, cover the finderscope or take it off to reduce the risk of light something on fire.  Use the the telescope’s shadow to find the sun. When the shadow is at it’s smallest, is should be pointing towards or near the sun. Again, don’t look through the scope! With an eyepiece in the focuser, hold the piece of paper behind the focuser and focus normally, except looking at the paper instead of looking though the eyepiece. How far away you hold the paper will determine the magnification. Watch small children, though, so they don’t look through the scope. Don’t keep your telescope pointed at the sun to long at one time either, it can melt the optics cement used in telescopes and eyepieces!

Full Aperture Telescope Solar Filter: This filter fits over the end of the telescope and allows for safe viewing of the sun. Use the shadow method to find the sun, don’t look through the finderscope!

I found this helpful for determining the exact transit times. http://transitofvenus.nl/wp/where-when/local-transit-times/

P.S. the projection method also works with one side of binoculars.

Clear skies, and enjoy the 2012 transit!