NASA: New data seems to confirm Voyager 2 is approaching interstellar space
Voyager 2 seems to have had enough of our solar system after 41 years. NASA has received new clues that seem to confirm that the spacecraft is approaching interstellar space, the part of a galaxy where there are no stars and planetary systems.
NASA reports that it has received new data from the Low Energy Telescope, part of the Cosmic Ray Subsystem instrument aboard Voyager 2. The data shows that since November the number of detected low-energy particles has fallen dramatically. That indicates that Voyager 2 is approaching interstellar space, because these particles basically originate within the heliosphere. The probe is likely located in the outermost layer of the heliosphere, where the solar wind is slowed by the pressure of interstellar gas.
Voyager 1 has been in interstellar space for years and this spacecraft showed a similar pattern: once heliopause was reached, the number of low-energy particles dropped significantly until they were no longer detected at all when entering interstellar space. Voyager 2 hasn’t reached zero yet, but the drop indicates the probe is getting close to the heliopause. The heliopause is the boundary between the heliosphere and interstellar space. In October, NASA reported that Voyager 2 was likely approaching the heliopause. There was an increase in cosmic rays, fast-moving particles coming from outside the solar system.
Voyager 2’s mission isn’t over once it reaches interstellar space; measurements are then made of the density and temperature of the plasma present. Plasma is the fourth state of matter next to solid, liquid and gas.
Voyager 2 was launched in 1977 and is currently located at a distance of nearly 17.9 billion kilometers from Earth. The probe was sent into space to study the planets Neptune and Uranus. Saturn was also visited. Voyager 1, launched several weeks later than Voyager 2, has been in interstellar space since 2012. This probe is currently located at a distance of 21.6 billion kilometers from Earth.
Roughly the locations of Voyager 1 and Voyager 2 – Image: NASA/JPL-Caltech