E-Mail IMAGE: Scientists hope the proposed Interstellar Probe will teach us more about our home in the galaxy as well as how other stars in the galaxy interact with their interstellar neighbourhoods. view more Credit: Johns Hopkins APL MUNICH -- When the four-decades-old Voyager 1 and Voyager 2 spacecraft entered interstellar space in 2012 and 2018, respectively, scientists celebrated. These plucky spacecraft had already traveled 120 times the distance from the Earth to the sun to reach the boundary of the heliosphere, the bubble encompassing our solar system that's affected by the solar wind. The Voyagers discovered the edge of the bubble but left scientists with many questions about how our Sun interacts with the local interstellar medium. The twin Voyagers' instruments provide limited data, leaving critical gaps in our understanding of this region.