Transit of Mercury: A Tiny Dot Crossing the Sun

A transit of Mercury occurs when the planet passes directly between Earth and the Sun.
Mercury appears as a tiny black dot slowly moving across the Sun’s surface.
These events happen about 13–14 times per century.
They can only occur in May or November, when Mercury’s orbit aligns with Earth’s.
The last transit was on November 11, 2019, and the next will be in 2032.
Transits helped astronomers refine measurements of the astronomical unit (Earth-Sun distance).
Observations require telescopes with solar filters for safe viewing.
Unlike a solar eclipse, Mercury is far too small to block noticeable sunlight.
Early astronomers used transits to test orbital theories and improve celestial mechanics.
Watching Mercury’s tiny shadow glide across the Sun connects us to centuries of skywatching tradition.