Mercury, the innermost planet in our solar system, has begun a transit that only happens about 13 times every 100 years. The transit is currently underway and you can watch it LIVE below.
The last transit happened in 2006, the next will happen in 2019, and there won’t be another one until 2032. Since it’s not wise to look at the Sun unless you’ve got a solar filter, you’re best to head to a planetarium or find a viewing event.