The smallest planet in the solar system passed between the Earth and the sun on November 11.
Huge numbers watched from observatories as Mercury made a transit of the sun, which only happens around 13 times every 100 hundred years.
The last time Mercury passed the sun was in 2016 but it is not due to happen again until 2032.
Mercury completes an orbit around the sun every 88 years, which means it passes between the Earth and the sun every 116 days.
The diameter of Mercury is 4,879 kilometres, which is approximately 38 per cent the diameter of Earth. If you put three of these planets side by side, they would be slightly bigger than Earth.
Although people enjoyed seeing Mercury move across the sun, they also had to be careful and wear protective glasses. Looking at the sun at any time of the day can be very dangerous and cause damage to your eyes.