It's the smallest planet in our Solar System, but also the fastest, with an orbit of just 88 Earth days. And while 48 million miles separates us from Mercury, on Monday, for the first time in 10 years, anyone on Earth (apart from the unlucky ones in Australia and New Zealand) could see the planet transit across the Sun.
The rare cosmic event has captivated many, including photographers who looked for ways to capture the tiny black spot as it made its way across the Sun.
Joel Kowsky of NASA was one of them. He captured this haunting photograph of the planet from the space agency's Washington headquarters.