Facts about Mercury (the planet)
- 07
The BepiColombo spacecraft, launched by the European Space Agency and Japan in 2018, will arrive at Mercury in 2025 to study the planet's magnetic field and geological history.
- 06
Mercury's thin exosphere contains oxygen, sodium, hydrogen, and helium ions knocked loose from the planet's surface by solar wind and micrometeorite impacts.
- 05
In 1974 and 1975, NASA's Mariner 10 spacecraft became the only probe to visit Mercury, revealing its heavily cratered surface resembles Earth's moon.
- 04
A day on Mercury lasts 58.65 Earth days, longer than its 87.97-day year, meaning the planet rotates more slowly than it orbits the Sun.
- 03
At just 4,879 kilometers in diameter, Mercury is smaller than Earth's moon and only slightly larger than our moon in absolute size.
- 02
Mercury orbits the Sun every 87.97 Earth days, making it the fastest planet in our solar system despite being the closest to the Sun.
- 01
Extreme temperature swings of 430 degrees Celsius occur on Mercury's surface between its sunlit and dark sides due to its lack of atmosphere.