If you don't want to wait another 105 years to watch Venus make its way across the face of the sun, here are ways to safely observe today's event, which starts around 2 p.m. PT.
You can watch NASA's live feed:
Or, watch it from the convenience of your smart phone via the Venus Transit app, available on Android and iOS. The app also lets you share your observations with other viewers.
If you want to do it the old fashion way, just remember, the same rule from the solar eclipse applies: do not look directly at the sun or you can get a serious eye injury.
NASA recommends several ways to address that, including wearing protective glasses like the ones used for the eclipse, or creating your own by punching a small pinhole in a cardboard box. You can also wear welder's glasses that have a No. 14 filter, or use telescopes with Solar Filters.
"No matter what recommended technique you use, do not stare continuously at the Sun," NASA writes. "Take breaks and give your eyes a rest! Do not use sunglasses: they don't offer your eyes sufficient protection."
The event will begin around noon in Honolulu, Hawaii, but this Transit of Venus site has start and end times for every location.
Watch carefully because this event won't happen again until 2117.