If all goes as planned, exactly six months from now, a tiny American robotic spacecraft down near the Sun will fire its engine to slow itself down and allow it to settle into a stable orbit around the planet Mercury. If it is successful, the MESSENGER probe will not only become the first man-made object to enter orbit around Mercury, but will commence a year-long intense study of one of the most mysterious planets in the Solar System.
The name Messenger is both a tortured acronym (which stands for MErcury Surface, Space ENvironment GEochemistry and Ranging) and a reference to the Roman god Mercury, who served as the messenger of the gods. It is the first exploratory mission to Mercury in three-and-a-half decades, and the first one devoted primarily to Mercury. The previous mission, Mariner 10, was focused on Venus and only flew past Mercury incidentally.
Mercury is sort of an orphan child as far as planets go. Mars has been studied by a veritable fleet of American, European, and Japanese orbiters and landers, while Venus, Jupiter and Saturn have also been visited by multiple spacecraft. Mercury has, until Messenger, been left out in the cold.
This is too bad, because Mercury is a fascinating world that has much to teach us. ecause it is so near the Sun, it is extremely difficult to study with Earth-based telescopes, making Messenger's mission all the more important. Mercury seems to have a reasonably strong magnetic field, suggesting a large molten core. There is tantlyzing evidence of water ice hidden in the craters on the north and south poles of the planet. It also appears to have an extremely thin atmosphere (referred to as an exosphere) which scientists are eager to learn more about.
Messenger is well equipped to study the planet. An impressive array of cameras, spectronometers, a laser altimeter, and other instruments will rigorously survey the geographical surface and probe the interior of the planet. The data sent back from Messenger should revolutionize our understanding of Mercury, and with it, our understand of the Solar System and our place within it.
However, it may be that Messenger is just a preview for an even bigger show. A combined European-Japanese probe is in the planning stages, called BepiColombo (after the scientist who first devised the gravity assist maneuver now commonly used by spacecraft throughout the Solar System). Currently planned for a 2014 launch and a 2020 orbital insertion at Mercury, the scientific instruments of this probe will be even more powerful than those of Messenger. While it is studying Mercury, it will also carry out experiments designed to increase our understanding of general relativity.
The exploration of space is a glorious collective enterprise undertaken on behalf of the entire human race by scientists from many nations and every conceivable background. It not only increases the overall knowledge of the human race, but it serves to demonstrate what is possible when human beings turn their intellectual powers away from the development of weapons of war and towards the enlightenment of the human mind.
Thank you for this thoughtful write-up!
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