Voyager 2 Enters Interstellar Space
Launched in 1977, Voyager 2 covered 18 billion kilometers of outer space. To achieve his goal, he had to leave heliopause - “a place where hot solar wind meets a cold, dense interstellar medium, ” as NASA writes in its press release. The solar wind is a plasma whose streams escape from the Sun, and the heliopause is the theoretical boundary at which its final inhibition occurs.
In 2012, Voyager 1 already left the heliopause limit. Unlike its predecessor, Voyager 2 is equipped with the Plasma Science Experiment (PLS) - a tool that will be able to accurately capture the intersection of this border. Scientists have been waiting for this moment for the past 11 years, and already at the end of October they began to believe that soon the probe would finally leave the heliosphere.
Despite the fact that the PLS device was created back in the late 70s, its data have already become an invaluable source for astronomers of information on plasma ions and electrons in an interplanetary medium. In addition, they got a unique opportunity to study the magnetosphere of giant planets - Jupiter and Saturn. A breakthrough in the heliopause will allow you to continue the work begun with Voyager 1 and explore deep space.
It is worth noting that technically not a single Voyager has left the solar system. The passage of the heliopause means that the Oort Cloud is still ahead. This “shell” surrounding the solar system, although considered interstellar space, is still subject to the weak gravity of the sun. According to scientists, the Cloud consists of more than a trillion icy space bodies, but no one can say for sure - not a single probe has ever flown so far as to explore this phenomenon. However, now mankind has a chance to uncover the mystery of the last curtain that separates our system from the vast expanses of outer space.