After a five-year trek of 1.74 billion miles — and at speeds up to 165,000 mph — NASA’s Juno spacecraft reached Jupiter Monday.
The $1.1 billion, solar-powered, unmanned spacecraft entered orbit around the largest planet in the solar system after launching in August 2011 and performing a speed-boosting fly-by of Earth in October 2013 on its journey to the gas giant.
Juno is equipped with nine instruments used to map the gravitational and magnetic fields of Jupiter, describe its interior and answer age-old questions: How much water exists there? Does the planet have a solid core? Why is the Great Red Spot shrinking?
Juno is the second spacecraft to orbit Jupiter and the first solar-powered craft to travel this far from the sun.
Galileo, launched in 1989, circled Jupiter for 14 years, beaming back photos and detecting signs of an ocean beneath the icy surface of Europa, one of its 67 moons.