
- Who
- Voyager 2
- What
- first first
- Where
- Not Applicable ()
- When
On 7th November 2019, the team monitoring Voyager 2's progress out of the solar system and into interstellar space announced that the boundary between our Sun's solar wind (heliopause) and true interstellar space is marked with a layer of higher density plasma at a temperature of 49,427C (89,000F) as the spacecraft crossed the edge of the Solar System. Although Voyager 1 passed through the same area earlier than Voyager 2, it's plasma sensors had failed. The higher density of plasma at the heliopause blocks cosmic radiation and levels increased dramatically as Voyager 2 entered true interstellar space. Our 'plasma shield' at the heliopause is undoubtedly responsible for keeping our solar system protected from very harmful levels of cosmic radiation.