Every century, the planet Venus makes two 6-hour treks across the sun (as seen from Earth).
The first so-called "Transit of Venus" happened in 2004, and the next happens, today, June 5, 2012.
You should make a point to check it out, as it won't happen again until 2117!
Fortunately, it's never been easier to observe the phenomenon. In 1874, eight American expeditions set out to record the Transit of Venus at a cost of $177,000.
You won't have to spend a penny! You can watch it live from your computer screen. NASA will be streaming the passage live from the summit of Mauna Kea, Hawaii.
There is also video documentaries and educational articles about Hawaii, Astronomy and the Transit of Venus.
You'll have everything you need to witness this once-in-a-lifetime event.
Live Webcast: venustransit.nasa.gov/webcasts/nasaedge/