● Mercury is only the second hottest planet. Despite being further from the Sun, Venus experiences higher temperatures.
● Mercury is named for the Roman messenger to the gods.
● In a very, very slow process, Mercury is getting smaller every day. It is estimated that the planet is about 9 miles smaller than it was four billion years ago.
● Mercury’s atmosphere is so weak, the planet has nothing to protect it against meteor impacts. This has filled its surface of crater impacts.
● The biggest crater in Mercury could fit Western Europe. The crater is about 963 miles in diameter.
● The days are very long in Mercury.
● The planet gets as close as 29 million miles (47 million km) to the sun.
● Mercury's iron core takes up about 75 percent of the planet's radius more than any other planet's in the solar system.
● It takes sunlight 3.2 minutes to travel from the Sun to Mercury.
● Mercury and Venus orbit the Sun within Earth’s orbit. This makes them inferior planets.
● Sometimes, Mercury streams particles off of its surface and results in a tail, similar to a comet.
● Both Venus and Earth are around three times bigger than Mercury.
● Though Venus is the closest planet to Earth, it spends most of its time far away. This makes Mercury the nearest planet to Earth.
● Mercury is about twice as large as Pluto.
● Mercury has been visited by two spacecraft: Mariner 10 and MESSENGER.
● The outer shell of Mercury is only 500 to 600 kilometers (310 to 375 miles) thick.
● Mercury’s magnetic field is just 1% of that of the Earth.
● Mercury has developed wrinkles that can be up to a mile high and hundreds of miles long.
● UV rays from the sun are around seven times stronger on Mercury than on Earth.
