That’s here; that’s home; that’s us—the two bright objects in this picture are Earth and the Moon, imaged by NASA’s OSIRIS-REx spacecraft on January 17, 2018 from a distance of 39.5 million miles (63.5 million km).
This is about the distance between Earth and Mars at their closest points to each other (give or take about 6 million miles) or about 165 times farther away from us than the Moon.
Voyager 2 may have been the second of NASA’s famous twin exploration spacecraft but it actually launched first, on August 20, 1977. Eight and a half years later it became the first (and, to date, last) spacecraft to visit Uranus, at 31,500 miles across the third largest planet in the Solar System. Voyager 2 made its closest pass by Uranus 32 years ago, giving us our best views ever of the enormous ice giant planet and its moons.
On this night in 1610 the Pisan astronomer Galileo Galilei looked up at a bright Jupiter at opposition through his handmade telescope and noted three little “stars” next to it, piquing his natural scientific curiosity. Further observations over the next few nights showed that the planet wasn’t moving relative to the little “stars” as it would have if they were indeed background stars. In fact the smaller objects (of which he soon saw four) were moving along with Jupiter, each in its own little path. He realized that the little objects weren’t stars at all but rather moons orbiting the giant planet—and, most importantly, not the Earth. This revelation helped change our entire view of the Solar System… and caused no end of trouble for Galileo as the Church didn’t appreciate a restructuring of their conveniently Earth-centered Universe. But it also opened the door for later discoveries of many more moons around other planets.
“We came all this way to explore the Moon, and the most important thing is that we discovered the Earth.”
– William Anders, Apollo 8 Commander
On Christmas Eve, December 24, 1968, the Apollo 8 CSM entered orbit around the Moon and, after completing 4 full orbits, provided the three astronauts on board with an amazing sight: a blue Earth rising* beyond the Moon’s cratered limb. Commander Frank Borman spotted the scene first and, after taking a 70mm black-and-white photograph, was able to rotate the Command Module so Earth remained in view through the small windows while CM pilot Jim Lovell captured this famous image on color film. It was the first time any humans saw the Earth from the vicinity of the Moon…and it was also the first Christmas that astronauts spent in space.
“The vast loneliness is awe-inspiring and it makes you realize just what you have back there on Earth,” Jim Lovell said.
On Feb. 7, 1984, astronaut Bruce McCandless II became the first “human satellite” when he performed the first test flight of NASA’s Manned Maneuvering Unit during STS-41B. Propelled by 24 small nitrogen-powered thrusters, the chair-like MMU allowed McCandless (who helped engineer the Unit at Lockheed Martin) to travel freely through space without any tethers or cords connecting him to a spacecraft. In the iconic image above, an edit of a photo captured by STS-41B pilot Hoot Gibson, McCandless is seen floating against the blackness of space. Here he was just a few feet away from the bay of the space shuttle Challenger, but he would eventually reach a distance of 320 feet (98 meters) from the orbiter!
A former Navy captain and previously Capcom for the Apollo 11 lunar mission, McCandless was 46 years old when he performed his historic tether-free EVA in 1984. This past Thursday, Dec. 21, 2017, Bruce McCandless II passed away at the age of 80.
“Our thoughts and prayers go out to Bruce’s family,” said acting NASA Administrator Robert Lightfoot. “He will always be known for his iconic photo flying the MMU.”