Nasa Spacecraft To Make Rare Flyby Of Mercury

09.28.09 | FL News Team

NASA scientists will get a rare close-up of Mercury today. The agency's Messenger spacecraft is scheduled to do a flyby just 142 miles over the tiny planet's surface. It will be the third time Messenger has passed so low over Mercury. The goal of today's flyby is twofold. It will bring the orbital close enough to map the last five to ten-percent of the planet that remains uncharted. The second purpose of the mission may be the most important, as it will determine whether Messenger will get an extended stay around the closest planet to the sun. NASA engineers plan to use Mercury's gravity to slow down the spacecraft. If all goes according to plan today, Messenger will be in the correct position to get caught in a permanent orbit around Mercury in March 2011.