The adventurers' current mission, the Voyager Interstellar Mission (VIM), will explore the outermost edge of the Sun's domain. › read more Question: Are the distance counters rolling backwards?
Answer: Often they are, and it's actually not an error.
The twin Voyager 1 and 2 spacecraft are exploring where nothing from Earth has flown before.
Continuing on their more-than-37-year journey since their 1977 launches, they each are much farther away from Earth and the sun than Pluto.
In August 2012, Voyager 1 made the historic entry into interstellar space, the region between stars, filled with material ejected by the death of nearby stars millions of years ago.
Scientists hope to learn more about this region when Voyager 2, in the "heliosheath" -- the outermost layer of the heliosphere where the solar wind is slowed by the pressure of interstellar medium -- also reaches interstellar space.
Scientists have three key indicators for determining whether the Voyager spacecraft have reached interstellar space.
1)"Inside Particles" A drop to about 2 particles per second of low-energy particles means that particles originate from inside the solar bubble.(Scientists consider a drop to the background rate of about 2 particles per second to mean there are no more inside particles.) 2) "Outside Particles" An increase and leveling off of high-energy particles coming in from far outside our solar system.Both spacecraft are still sending scientific information about their surroundings through the Deep Space Network, or DSN.The primary mission was the exploration of Jupiter and Saturn.After making a string of discoveries there -- such as active volcanoes on Jupiter's moon Io and intricacies of Saturn's rings -- the mission was extended.Voyager 2 went on to explore Uranus and Neptune, and is still the only spacecraft to have visited those outer planets.