(Sen) - NASA's Messenger space exploration probe is now orbiting Mercury and sending back pictures.
Launched from Earth in 2004, NASA's MErcury Surface, Space ENvironment, GEochemistry, and Ranging, or MESSENGER, entered orbit on 18 March 2011.
Before entering into orbit, Messenger had to be slowed down. To achieve this, Messenger was programmed to fly past Mercury three times, each time being slowed down by Mercury's gravitational pull. Messenger was then travelling at the right speed to enter into Mercury's orbit in March 2011.