Mercurial Musings

For the first time since 1975, a manmade spacecraft is surveying the innermost planet of our Solar System.

MESSENGER, which stands for "MErcury Surface, Space ENvironment, GEochemistry, and Ranging," left Earth's surface back in 2004 and took the long way round the inner Solar System before reaching its final destination on March 17th, 2011. And when I say "long," I mean 4.9 billion miles long. The full route consists of multiple flybys of Earth, Venus, and Mercury itself, as visualized in this animation. (For a more detailed discussion of gravitational assists, see my previous post on MESSENGER here.)

Now, almost eight years later, MESSENGER has settled into its new home and will begin taking data next week. The spacecraft's primary mission is to look for answers to such questions as: Why is Mercury so dense? What is the nature of Mercury's magnetic field? And what is the structure of Mercury's core?

Of the terrestrial planets in our Solar System, Mercury is by far the smallest and densest. Its surface is extremely old and undergoes daily temperature swings of over 1000 degrees. And its also the least explored. The better we can understand how Mercury formed and evolved, the better we can understand the conditions during the formation of our Solar System -- and our Earth.

Designing, building, and operating MESSENGER is no small feat. Neither is launching a sophisticated chunk of electronics into space and maneuvering it through the solar neighborhood. The scientists and engineers who got it there deserved to be celebrated. As does our desire to explore.

(Image credit: http://www.nasa.gov/mission_pages/messenger/main/index.html)