The Hot Planet called Mercury
Mercury got its name from the Roman god of commerce, travel, and thievery. Although they knew it was the same apparition, the Greeks referred to it as Apollo (for appearing as a morning star) and Hermes (for being an evening star).
In 1974 and again in 1975, Mariner 10 flew by the planet. Because of its close proximity to the Sun, only 45% of the surface was mapped.
Up until 1962, it was believed that a day on mercury was the same length as its year. It was realized to be untrue after dopplar radar observations determined that it rotates three times in two of its years.
Quick Facts About Mercury
- It is the cloest planet to the sun, and therefore the hottest of all the planets in the solar system.
- With the exception of Pluto (which is said NOT to be a planet), Mercury is the smallest planet.
- Since Mercury is so close to the sun, it also has the fastest orbit. It orbits 57,910,000 km from the Sun.
- It's diameter is 4,880 km with a mass od 3.30e23 kg.
- The temperature on Mercury varies between 90 K to 700 K, making it the most extreme variation in the solar system.
- Mercury has a large iron core whose radius is 1800 to 1900 km. Its outer shell is only 500 to 600 km thick.
- Mercury has a thin atmosphere that is constantly being replenished. It is created when atoms from its surface are blasted off by the solar winds.
- The surface is heavily cratered, alot like our moon.
- Radar observations show that there is some water ice in the shadows on the north pole.
- The magnetic field around Mercury is only 1% as strong as the Earth's.
- Mercury has no known moons.
- Spectroscopic studies have shown that Mercury does not have any iron on its surface, although it has a large iron core.
Mercury Websites
Space Today Online - Exploring the Planet Mercury
Spacelink - Mercury
Kosmoi: The Planet Mercury
Solarviews - Mercury
