Mercury's Transit

Can you see this small unusual spot on the Sun? If you look closely, it is almost perfectly round…

Image credit David Cortner

The dot is the result of an unusual type of solar eclipse that occurred in 2006, at the time planet Mercury passed in front of the sun. Mercury’s Transit.

The situation could technically be labeled a Mercurian annular eclipse with an extraordinarily large ring of fire. From above the cratered planes of the night side of Mercury, the Earth appeared in its fullest phase. Hours later, as Mercury continued in its orbit, a slight crescent phase appeared again.

Mercury's Transit

Mercury’s Transit.  Credit NASA

This was ten years ago — the next Mercurian solar eclipse will occur today.

Planet Mercury

Planet Mercury.  Credit NASA

source APOD