By Keith Laing - 03/18/11 07:19 PM EDT
The spacecraft was slowed down 1,929 miles per hour to join the orbit, which NASA said was 96 million miles from Earth.
NASA celebrated the successful maneuver.
“Despite its proximity to Earth, the planet Mercury has for decades been comparatively unexplored,” Messenger principal investigator Sean Solomon said in a statement.
“For the first time in history, a scientific observatory is in orbit about our solar system’s innermost planet. Mercury’s secrets, and the implications they hold for the formation and evolution of Earth-like planets, are about to be revealed."