Mercury will pass in front of the sun on Monday, appearing as a dark spot moving across the star’s bright surface.
The cosmic event, which is called a transit, will last for roughly 5.5 hours and started at 7:35 a.m. ET.
Unlike a solar eclipse, you can’t see Mercury’s transit with the naked eye. But stargazers have to take precautions.
NASA recommends heading to a local astronomy club to use a “specialized, properly-filtered solar telescope.”
"You cannot use a regular telescope or binoculars in conjunction with solar viewing glasses,” according to NASA.
Mercury in transit is a major event, and a rare one. We won’t be able to see the transit again until 2032.