On June 6th of this year, a very rare event will occur in our skies at sunset: the planet Venus will meander through its orbit along a path that takes it between the Sun and the Earth, making it visible during the day as a dark spot on the bright disc of the Sun. This isn’t an eclipse (scheduled by the way for May 20th); this is something very rare, and a bit different – a transit.
Planets all orbit around the Sun at different rates, so every now and then, they line up. When the Moon crosses between us and the Sun, it blocks it out briefly, but planets are farther away and much smaller, so they appear as little dark spots crossing the bright disk. From our perspective, Venus transits the Sun twice (in two events eight years apart) every hundred or so years. The last one was in 2004, and the next two will be in December of 2117 and 2125, respectively. Hopefully that gives you a sense of how rare this is!
We cannot, of course, look directly at the Sun. Building a Solar viewer is very easy though – you only need two pieces of stiff poster board (or similar), some aluminum foil and a pin. By covering one piece of board with aluminum foil and poking a pinhole in it, the image of the Sun can be shone on the second piece. Simply place your pinhole board between the plain board and the Sun, and you can focus an image by moving the pinhole board closer and farther from the projection surface (plain board).
It is also possible to use binoculars or a telescope to project an image onto a page or piece of board, but these need to be covered or aimed away from the Sun frequently (at least every minute or so) to avoid damaging their lenses (from overheating!). Never look directly at the Sun without specially-made Sun viewing filters, especially through binoculars, a telescope or a camera.
If you’re looking for another rare opportunity you’ve got to check out the Discovery Centre’s upcoming new exhibit – Be the Dinosaur. This exhibit, the first time in Canada, will give you the opportunity to become a T-Rex or Triceratops through a sophisticated but super-cool video simulation that puts you right in the middle of a dinosaur world. Rare indeed!