As we move away from the Sun in our Tour of the Solar System, the first large body we meet is the smallest planet in our solar system: The planet Mercury. Mercury looks a lot like our moon, but is it made primarily up of iron.
Mercury is about one third larger than the moon. Since it is so close to the Sun, it only takes about three months to complete its orbit. Due to the quick orbit, and close proximity of the Sun, Mercury is always either visible from Earth either in the early evening or early morning. It makes a swap about every months, depending on its location in its orbit around the Sun.
NASA was successfully in sending two spacecraft to Mercury. The first orbited the little planet for about a year in the mid 70s as Mariner 10. The Messenger mission reached the planet early this year and will continue mapping the planet.
As one would expect, Mercury is a hot place. The average temperature is 442 K. Since there is no atmosphere the planet has wild temperatures swings from around 110K on the dark side, to 700 K during the Mercurian daylight hours.
Scientist have speculated that since deep craters at Mercury's poles are never exposed to direct sunlight, that ice is able to form. It would seem that this is a rather odd place for ice to exist, and a hot planet so close to the Sun. But it is theoretically possible
No comments:
Post a Comment