Mercury is the closest planet to the sun (innermost planet) in the solar system. It's about 2/5 the size of Earth. This planet is a lot like the moon, such as;
- No atmosphere- so really hot in areas with sunlight and cold without it.
- Covered with craters
But unlike the moon, Mercury has a huge iron core, which makes a magnetic field a bit stronger than Earth's.
Mercury can't be seen from the Hubble Space Telescope, because it's seen too close to the sun and if the telescope's pointed at the really bright sun, the instruments might break.
The Messenger spacecraft is planned to begin its mission at the beginning of April. Hope they'll get new facts about this planet.
I actually thought Mercury was pretty boring compared to the other planets in the solar system. Well, I guess it's getting pretty interesting.