On August 25, 2012 Voyager 1, part of NASA’s Voyager Program, became the first spacecraft to cross the heliospause and enter the interstellar medium. Heliospause is the boundary of the heliosphere. It is a spherical region around the Sun that is filled with solar magnetic fields and the outward-moving solar wind. Two probes, Voyager 1 and 2, were launched in 1977 to study the outer planets in our solar system, but subsequently, their missions were extended to explore the world beyond. Voyager 2 too entered the interstellar medium on November 5, 2018. Both the probes remain operational past expectations and continue to send information about the outer expanses of the Solar system. Aboard each spacecraft is a golden record, a collection of sights, sounds and greetings from Earth. It is basically a 90-minute mixtape for any extraterrestrial passerby who might stumble upon one if the two Voyager spaceships at some points in the future.
Picture Credit : Google