Artemis II Enters Lunar Sphere of Influence for First Time Since Apollo 17 in 1972

The crew’s Orion capsule entered what’s known as the lunar sphere of influence at around 12:41 a.m. ET Monday, crossing into the region of space where the moon’s gravitational pull is stronger than the pull of Earth’s. The lunar sphere of influence isn’t a physical or tangible border. Rather, it’s a mathematical boundary that signifies that the astronauts are in the moon’s vicinity. Crossing the threshold is a major achievement for NASA. It’s the first time that astronauts have entered the lunar sphere of influence in more than half a century, since the Apollo 17 mission in 1972. The astronauts are set to swing around the moon later Monday, reaching an estimated distance of 252,760 miles from Earth the farthest any humans have ventured from our home planet.