Inner most planet Mercury passing directly between Earth and the Sun seen through a thin cloud cover from Copenhagen in November 2019.
Next time we can see Mercury in front of the Sun is on November 12-13 in 2032 and will, like this one, be visible from all over the World where the Sun is up and there are no clouds.

Mercury is the closet planet to the Sun in our solar system and it’s distance to the Sun is a little more than 1/3 of the distance between Earth and the Sun.
Mercury is also only a little bigger than 1/3 of the size of Earth – or about 1,5 times bigger than our Moon – so if Earth were the size of a baseball, Mercury would be about the size of a golf ball.

As Mercury revolves very quickly around the Sun but very slowly around itself, one day is longer than one year on Mercury – actually it’s daytime for one Mercurian year, and nighttime for one Mercurian year 🙂