NASA researchers have found that the structure of the solar system boundary or "stellar wind bubble" can change. This is indicated by the data obtained by the space probes Voyager 1 and Voyager 2. The opening is reported by the Gizmodo edition.
The "stellar wind bubble" (heliosphere) is the region in which the particles emitted by the sun fly relative to it at supersonic speed. The heliosphere is bounded by a shock wave that occurs when the solar wind collides with the interstellar medium. The boundary of the "bubble" is considered the boundary of the solar system, and in 2012 Voyager 1 became the first man-made object to cross it.
Before leaving the solar system, the device collected data on the heliospheric mantle - an intermediate zone between the boundary of the heliosphere and the boundary of the shock wave, where the solar wind speed drops to sound values. The probe recorded the growth of high-energy particles called cosmic rays. However, Voyager 2, which is currently still in the heliospheric mantle within the bubble, showed no change.
Scientists believe that this phenomenon is due to the fact that the Sun is in the active phase of its cycle. This, in turn, enhances the solar wind, which prevents the penetration of cosmic rays into the heliosphere. Thus, the "stellar wind bubble" is a dynamic structure that can be both a barrier for high-energy particles and let them pass inside.
Voyager 1 was launched on September 5, 1977 to explore Jupiter and Saturn. Now the device is located at a distance of 0.00217 light years from the Sun. Voyager 2, launched on August 20, 1977 and visiting Uranus and Neptune, is 0.00174 light years away.