(CNN) - Mercury is gliding across the sun on Monday in an event called a transit.
It happens only 13 times per century, and the next one isn’t set to happen until 2049.
Mercury will look like a small black dot on the sun starting at around 7:35 a.m. EDT.
Its full path across the sun will take 5 1/2 hours.
Binoculars or a telescope will be needed to see the event. Attending a viewing party at a local museum or an astronomy club event is suggested since looking directly at the sun is harmful.