|Mercury, the smallest one|
Mission to Mercury
Late on St. Patrick’s Day, Eastern time, a spacecraft called Messenger, weighing a little more than a thousand pounds, slipped into an elliptical orbit around the planet Mercury, becoming the only manmade object to orbit the planet closest to the Sun.
Through the coming days, scientists from NASA and the Johns Hopkins University Applied Physics Laboratory will check Messenger’s systems and begin turning on its instruments. On April 4, observations begin.
Messenger spent nearly seven years in transit and traveled about five billion miles. It will spend one Earth-year studying the mineralogy of Mercury, mapping its surface and magnetic and gravitational fields, and trying to identify the substance covering the planet’s north pole. All the while, a ceramic-fabric sunshade will be protecting Messenger from the ferocious heat of the nearby Sun and the solar reflection from Mercury. The craft will eventually plummet into the planet.
It really doesn’t matter how many space missions you’ve followed or how many Hubble photographs you’ve marveled over. There is still a sense of raw excitement about reaching a critical stage in an expedition like this, an excitement that will only grow as data begins to stream toward Earth.
Part of the thrill is knowing that this is the pure pursuit of knowledge, the scientific impulse — a human impulse — carried to a remarkable conclusion. It’s hard to know just what we will learn about Mercury. Like all scientific missions and experiments, this is a journey to a more refined sense of what we don’t yet know.
I do not know about you but I still can feel the excitement and emotion of the previous of Voyager missions and how I was counting the minutes for the first pictures to reach us....