Voyager 2 crosses the heliopause at 119 AU
Six years after its twin and about 2.6 AU closer to the Sun, Voyager 2 crossed the boundary with a working plasma instrument aboard. It recorded a boundary layer roughly 1.5 AU thick in which the plasma slowed, heated and roughly doubled in density, then a transition into interstellar plasma that took less than a day. The interstellar plasma outside was measured hotter than models had predicted.
Observed — measured or witnessed, with the observation cited.
Subjects
- Voyager 2 · mission · Interstellar space, on a southward trajectory out of the ecliptic plane · not located
- Heliopause · natural phenomenon · not located
- Very local interstellar medium · natural phenomenon · not located
Evidence
Partly verified — Core facts are sourced; some optional detail is deliberately absent. This is the standing of the weakest source, not an average.
Voyager 2 plasma observations of the heliopause and interstellar medium
Voyager 2 crossed the heliopause on 5 November 2018 at 119 AU; a boundary layer about 1.5 AU wide preceded it in which the plasma slowed, heated and was roughly twice as dense as typical heliosheath plasma; the transition took less than a day, and the interstellar plasma immediately outside was hotter than predicted, of order 30,000–50,000 °C against a prediction nearer 15,000–30,000 °C. V55 verification basis: the paper was not fetched — nature.com is blocked to this session — but search results carried these figures and attributed them to it.
Nature Astronomy · 2019-11 · Verified
Richardson, J. D., Belcher, J. W., Garcia-Galindo, P. and Burlaga, L. F., Nature Astronomy, doi:10.1038/s41550-019-0929-2
NASA's Voyager 2 Probe Enters Interstellar Space
NASA announced on 10 December 2018 that Voyager 2 had crossed the heliopause on 5 November 2018, confirmed by a sharp fall in solar wind particle intensity and a simultaneous rise in galactic cosmic rays measured by an instrument suite that, unlike Voyager 1's, included a working plasma science experiment. V55 verification basis: the release was not fetched; the substance is carried in search results attributing it to NASA and JPL.
NASA / Jet Propulsion Laboratory · 2018-12-10 · Partly verified
NASA news release, 10 December 2018, https://www.nasa.gov/news-release/nasas-voyager-2-probe-enters-interstellar-space/
Recorded on Voyager 2
- The full Grand Tour is cancelled and rebuilt as a two-spacecraft mission
- Voyager 2 launches
- Voyager 2 closest approach to Jupiter
- Voyager 2 passes Saturn and continues towards Uranus
- Voyager 2 reaches Uranus — the only close encounter ever made
- Voyager 2 passes Neptune and Triton, ending the planetary programme
- Voyager 2 crosses the termination shock at about 84 AU
- Voyager 1 crosses the heliopause at 121.6 AU
- The 2012 crossing is confirmed from plasma oscillations
- Voyager 2 crosses the heliopause at 119 AU
- Voyager 2's low-energy charged particle instrument is switched off
- The "Big Bang" power manoeuvre on Voyager 2
Related
Related because they share a subject in the Atlas — never because the text looks similar.
- The "Big Bang" power manoeuvre on Voyager 2 · 2026-07-09
- Voyager 2's low-energy charged particle instrument is switched off · 2025-03-24
- The 2012 crossing is confirmed from plasma oscillations · 2013-09-12
- Voyager 1 crosses the heliopause at 121.6 AU · 2012-08-25
- Voyager 2 crosses the termination shock at about 84 AU · 2007-08-30
- Voyager 2 passes Neptune and Triton, ending the planetary programme · 1989-08-25
- Voyager 2 reaches Uranus — the only close encounter ever made · 1986-01-24
- Voyager 2 passes Saturn and continues towards Uranus · 1981-08-25