( CNN ) -- NASA 's Mercury probe Messenger has become the first spacecraft to go into orbit around the closest planet to the Sun . Confirmation of the probe entering Mercury 's orbit was received Thursday evening . `` Achieving Mercury orbit was by far the biggest milestone since Messenger was launched more than six and a half years ago , '' said Messenger Project Manager Peter Bedini , of the Johns Hopkins University Applied Physics Laboratory . `` This accomplishment is the fruit of a tremendous amount of labor on the part of the navigation , guidance-and-control , and mission operations teams , who shepherded the spacecraft through its 4.9-billion-mile ( 7.9-billion-kilometer ) journey . '' The space agency is hoping to get the first pictures back from the Messenger probe in orbit by the end of the month . The primary science phase of the mission is scheduled to begin April 4 . `` Despite its proximity to Earth , the planet Mercury has for decades been comparatively unexplored , '' said Sean Solomon , Messenger principal investigator . `` For the first time in history , a scientific observatory is in orbit about our solar system 's innermost planet , '' he said . `` Mercury 's secrets , and the implications they hold for the formation and evolution of Earth-like planets , are about to be revealed . ''
It took the probe more than two years to get to Earth . It 's a 4.9-billion - mile ( 2000 - kilometer ) journey to the solar system 's innermost plant . The space agency is hoping to get the first pictures from the probe by the end of the year . The primary science phase of the mission is scheduled to begin April 4 .