MESSENGER (MErcury Surface, Space ENvironment, GEochemistry, and Ranging), launched August 3, 2004, is NASA's first mission back to Mercury in over 30 years. The first mission to visit Mercury was Mariner 10. It flew by the planet three times between 1974 & 1975. During that time, it only imaged about 45% of Mercury.
Unlike Mariner 10, MESSENGER is designed to orbit Mercury. But, in order to get there, MESSENGER will make one flyby of the Earth, two flybys of Venus, and three flybys of Mercury. During MESSENGER's three flybys of Mercury, it will have imaged the whole planet. The first of the three flybys will take play on January 14, 2008. It won't be until March 2011 when MESSENGER will enter into an orbit around Mercury.
Once in orbit, MESSENGER will begin to gather data to better understand Mercury and how the other planets formed. Scientist hope to answer the following six questions:
- Why is Mercury so dense?
- What is the geologic history of Mercury?
- What is the nature of Mercury's magnetic field?
- What is the structure of Mercury's core?
- What are the unusual materials at Mercury's poles?
- What volatiles are important at Mercury?
Stay tuned for future blogs on MESSENGER.