By Charles Apple
Launched 43 years ago, the two Voyager space probes have left our solar system and are now traveling in interstellar space. Both probes should continue to communicate with us for another five years.
Launched: Sept. 5, 1977
Distance from Earth: 13.9 billion miles
Current speed: 38,026 mph
Time it takes for a signal from the probe to reach Earth: 20 hours
Launched: Aug. 20, 1977
Distance from Earth: 11.5 billion miles
Current speed: 34,400 mph
Time it takes for a signal from the probe to reach Earth: 17 hours
The Voyager missions were designed to take advantage of a certain alignment of outer planets occurring in the late 1970s and 1980s that takes place about every 175 years. The probes approached a planet, photographed it and its moons and then used that planet's gravity to slingshot itself to the next planet. Voyager 2's time to Neptune was reduced from 30 years to just 12, NASA says.
Sources: NASA's Jet Propulsion Laboratory, the New York Times, NPR, PBS, Space.com, Heavens-Above.com | ALL IMAGES FROM NASA'S JET PROPULSION LABORATORY