NASA'S Juno spacecraft capped a five-year journey by slipping into orbit around Jupiter where it will study the biggest planet in the solar system, the U.S. space agency said on July 5.
Juno achieved the milestone of orbit just before midnight Florida time, to the cheers of NASA employees.
Juno has traveled 1.7 billion miles since launch and was traveling at more than 130,000 miles per hour before it slowed down for the transition into orbit.
Part of Juno's science mission is to learn if Jupiter has a dense core beneath its clouds and map its massive magnetic field.
The probe also will hunt for water in Jupiter's thick atmosphere.
Earth and Mars were positioned at the right distance from the sun for liquid surface water, which is believed to be necessary for life. Scientists have been studying Mars to figure out why the planet lost its water.
Jupiter's immense gravity also diverts many asteroid and comets from potentially catastrophic collisions with Earth and the rest of the inner solar system.
NASA expects Juno to be in position for its first close-up images of Jupiter on August 27.