Sun Day, Fun Day

It’s been “showtime” for the Sun lately. The Sun’s first act: last Sunday’s “ring of fire” eclipse. On the West Coast, the Moon passed in front of the Sun just before sunset. Because the Moon covered only 75% of the Sun (depending upon where you were watching), the Moon appeared to be surrounded by a fiery ring. It was a dazzling display that happens once a year.

Now we are poised for the transit of Venus. On June 5-6, depending upon your location, the planet will pass in front of the Sun, an event that won’t happen again in our lifetimes. Transits happen in pairs — two journeys across the Sun eight years apart and then not again for 100+ years. In fact, only seven transits of Venus have been recorded since the invention of the telescope: 1631, 1639, 1761, 1769, 1874, 1882, 2004.

The transit of Venus has played a prominent role in astronomical history. In 1677, Edmond Halley (of Halley’s comet fame) urged his fellow astronomers to track the next transit of Venus in 1761, believing that careful observation would help them calculate Earth’s distance from the Sun (93 million miles) and know the size of our solar system. In 1761 and 1769, scientists mounted numerous expeditions to observe the transit and make calculations. Scientists who often worked solo risked life and limb traveling to the far reaches of the Earth for this international science effort.

How best to observe the transit of Venus?

• First, find out when you can see the transit in your area … here.
• Check with your local planetarium or science center to see if it is hosting a viewing event.
• If not, you can build your own viewer or purchase special glasses (which cost about $2 a pair). Find instructions and/or a list of glasses suppliers…here.

• For teachers, the Smithsonian has a wonderful Venus Teacher Resource Page.
• One of the most comprehensive sites about the transit, history and viewing is TransitofVenus.org.
• Also, stay tuned for this Sunday’s Mini Page in your local newspaper, which is all about the Transit of Venus.