Mercury Planet
Mercury is the closest plant to the Sun in our solar system. Despite this fact, it has only been visited by one space probe, which means there is relatively little information on the Mercury Planet.
Mercury Planet
Mercury is a terrestrial planet meaning it has a rock surface. Although it maintains a very weak magnetic field, the atmosphere of Mercury is minimal. The biggest thing of interest regarding Mercury is the incredible density.
Although Mercury is the smallest of the terrestrial planets, it is the densest by far when calculating pure mass. Of great interest, 65 percent of the planet appears to be comprised of pure metal, twice the amount of the Earth. Being metal rich, the planet has become a point of great interest in the scientific community.
The only spacecraft to observe Mercury from a relatively close position was Mariner 10 in 1974-5. While Mariner 10 returned interesting information, the level of technology at that time was limited. Frankly, not much was learned, but that is about to change.
In 2004, NASA launched a mission to Mercury. The name of the craft is Messenger and it is expected to arrive at the planet in 2011. The mission is designed to obtain information to answer some very important questions.
The major issue to be resolved by the mission is why is Mercury so dense? Currently, there are three conflicting theories explaining the density, but no real facts backing them up. The theories are:
- When forming, the glass cloud surrounding the planet attracted dense particles, which attracted massive amounts of metal. If true, Messenger should find the surface of the planet to be similar in composition to the other terrestrial planets [Earth, Mars, and Venus].
- The second theory is the burned to a crisp idea. The idea is the vicious heat and radiation from the Sun vaporized much of the crust of Mercury and the only thing remaining is the dense metal core. If true, this would mean Mercury was originally a very, very large planet.
- Finally, some scientists have theorized that massive impacts on the planet around the time it was formed stripped off the outer layers of the planet. While it is true that Mercury has some monstrous craters, this theory seems the least promising of the three.
Despite the fact Mercury is one of the planets originally discovered by the first astronomers, we know very little about it. With the Messenger mission, hopefully we will start to unravel the mysteries of the Mercury Planet.
