Earlier today, the planet Mercury spent 5.5 hours crossing in front of our sun from our perspective, known as a “transit.” It’s a pretty rare event as Mercury won’t transit the sun again until 2032. The only other planet in our solar system that can complete a transit of the sun from our vantage point is Venus since it’s also closer to the sun than we are. Venus completed its last transit on June 6, 2012 and won’t transit the sun again until we’re all in the grave (December 11, 2117). That’s kind of a wild thought. Below is more information on this rare celestial event.