Astronomers are used to seeing spots on the sun, but there's something special about the one gliding across today. That spot is actually Mercury, and you can see it illuminated right now as it passes between the Earth and the sun.
Mercury glided in front of the sun at around 7:12 a.m. Eastern this morning, according to NASA. It'll reach the halfway point around 10:47 a.m., and then move past the sun at about 2:42 p.m. The whole transit will take about 7.5 hours. The best time to watch is between 10:30 and 11:30 a.m., according to Gizmodo.
Here you can see the path Mercury will take:
Looking directly at the sun is dangerous, so you should only watch the event if you have a telescope with a solar filter on hand or a way to project the sun onto a piece of paper. If you don't, both NASA and the European Space Agency are streaming the transit live.
The transit will be visible from South America and most of North America and Europe.
This Mercury transit is a rare occurrence that only happens a few times per century. The next one won't happen until November 11, 2019.