Mercury

Mercury was formed 4.5 billion years ago by converging dust, rocks, and gasses. It was discovered in 265 BC, and was named "Mercury". But who knows exactly? The Romans named it after their messenger god (their fastest god) they prayed for success in business. Mercury was in fact known since ancient times, the reason is that it can be seen without advanced telescopes. It is the smallest planet (about a bit bigger than the moon) in our solar system, and it is the closest to the sun. It is about 57 million kilometers away from the sun (about 35 million miles). Mercury takes about 59 Earth days to take a full rotation, and completes a full revolution around the sun in 88 Earth days. So far Mercury has had two spacecrafts on the surface, and they were Mariner 10 and MESSENGER. During the day Mercury has an average surface temperature of a whopping 800 degrees Fahrenheit and 430 degrees Celsius. In the night, it goes way way down: its surface temperature can go as low as -290 degrees Fahrenheit and -180 degrees Celsius. Mercury's changes in temperature is the most rapid in the solar system. Due to Mercury having a core with a weird size, it has began to shrink as the core cooled and contracted, pulling the surface inward. Mercury is covered in a lot of craters from various impacts. There is one called the Caloris Basin. It is 1,300 kilometers and 807 miles across.

If you'd want to know what mercury is made of it is right here: Mercury is a terrestrial planet. It basically means it is an Earth-like planet. It is made up of rocks or metals and its surface is in fact hard. It has a iron core that takes up nearly 75% of the planets diameter. Its core has more iron than any entity in our solar system. Now about the the mass of Mercury: it has a radius of about 2,440 km and that's 1,516 miles. I said earlier in these facts that Mercury is the smallest planet and the smallest major planet. That means its about a little more than one third of the size of Earth, and about the size of the U.S.

Fun Facts:

• If you lived on Mercury you would have a birthday in a fast 3 months - you would age so fast!

• Some people think Mercury is the hottest planet because its next to the sun, but actually its not. Its actually Venus (you should check the page out).

• If you can see, Mercury has no moon. That is pretty interesting.