Next week, Venus is going to pass between us and the sun. The moon did it very recently, and far more dramatically. The moon does it all the time – there are solar eclipses every year somewhere on Earth. Even when the moon doesn’t completely block the sun – such as the annular eclipse last month – it’s called an eclipse.
But Venus … well, it’s just too far away to appreciably block the sun. In fact, without special equipment for viewing it, you won’t even know it’s happening. (Unless someone tells you.) So it’s not an eclipse, really. (Though I really like the name “Venal eclipse”. Don’t you?) No, it has the much more pedestrian name, “Transit of Venus”.
But don’t let the name fool you. This is a rare and scientifically valuable event. Transits of Venus have been used as far back as the 17th century to estimate the size of the solar system. Also, we only get two transits in over a century. They come in pairs about 8 years apart. We had one in 2004; before that, the last one was in 1882. After this one, we won’t have another transit until 2117.
So check out what events your local observatory or science centre is hosting (here in Edmonton, the Telus World of Science has a free viewing event). Or set up your own viewing equipment. (Don’t try watching with your naked eyes or sunglasses. You won’t see the transit, and you’ll hurt your eyes.)
I’m planning on using the pinhole box method. I’ll let you know how it goes.
PS: Here’s a nice website full of information about the transit. I think they even have phone apps. And don’t worry – if you miss seeing it yourself, I’m sure there will be plenty of videos and photos online to enjoy it second hand.