Go ahead and mark this one on your calendar now because you will not get another chance to see it in your lifetime.
It's been quite the year for spectacular astronomical sights. There was the supermoon, annular solar eclipse, and now the transit of Venus, which will occur tonight. This is when Venus passes directly between the earth and the sun and we see the distant planet, as a small dot passing slowly across the face of the sun. You can actually see this unusual alignment later this evening and through sunset (between about 6PM and 8PM). The weather in D.C. looks fairly good for transit gazing; however, there may be a few clouds that could block the view.
- Best Time To See Venus Transit In D.C.
Interestingly and historically, this rare alignment is how we measured the size of our solar system. For those of you who have smart phones, there’s an app for this. The phone app is creatively called the VenusTransit phone app and will actually allow everyone to send their observations of the transit to participate in a global experiment to measure the size of the solar system.
The last Venus transit was in 2004. After tonight's transit, we won't see the transit of Venus, again, until 2117. If you missed the transit viewing in 2004, this is a once in a lifetime opportunity!
Do not try to observe the transit of Venus directly! You must use proper eye protection at all times with the proper solar filters. You still have time to order a pair of glasses online and here is a place where I know you can get them dirt cheap. Enjoy the show!