How to Watch Transit of Mercury
If you’re unfamiliar with the transit of Mercury, this phenomenon takes place when the planet Mercury passes directly between the Sun and a superior planet, becoming visible against the solar disk. When this happens, Mercury appears as a tiny black dot moving across the disk of the Sun. The closest planet to the sun began its transit today at 7:35 a.m. EST and will continue its journey for approximately 5.5 hours. Read more for a livestream video and additional information.

Transits of Mercury normally occur in May or November. The last four transits occurred on November 15, 1999; May 7, 2003; November 8, 2006; and May 9, 2016. The current one is happening now on November 11, 2019, and then the next is going to occur on November 13, 2032. A typical transit lasts for several hours.

On a related note, the Mars rover Curiosity observed the planet Mercury transiting the Sun on June 3, 2014, marking the first time a planetary transit has been observed from a celestial body besides Earth.