Active volcanism found on Io
Three days after closest approach, navigation engineer Linda Morabito was processing a deliberately over-exposed optical navigation frame — taken to fix the spacecraft's position against background stars — when a crescent of light appeared off Io's limb. It was an eruption plume, and it was the first active volcanism observed anywhere beyond Earth. The finding came from an image taken for engineering purposes, not from a planned science observation.
Historical — it happened, and the record is settled.
Subjects
Evidence
Partly verified — Core facts are sourced; some optional detail is deliberately absent.
Discovery of currently active extraterrestrial volcanism
An eruption plume was identified on Io's limb on 8 March 1979 in an over-exposed Voyager 1 optical navigation image, the first active volcanism observed beyond Earth. V55 verification basis: NOT CHECKED IN THIS RUN. The author list, volume and date are given from standard citation practice and the page number is deliberately omitted because it was not confirmed.
Science (American Association for the Advancement of Science) · 1979 · Partly verified
Morabito, L. A., Synnott, S. P., Kupferman, P. N. and Collins, S. A., Science 204 (1979)
Recorded on Io
- The full Grand Tour is cancelled and rebuilt as a two-spacecraft mission
- Pioneer 10 passes Jupiter — the first spacecraft to reach the outer Solar System
- Pioneer 11 passes Jupiter, bending north toward Saturn
- Voyager 1 launches
- Voyager 1 closest approach to Jupiter
- Active volcanism found on Io
- Voyager 2 closest approach to Jupiter
- Voyager 1 passes Saturn and Titan, and leaves the plane of the planets
- Voyager 1 photographs the solar system from outside it
- Galileo enters orbit around Jupiter — the first outer-planet orbiter
- Cassini passes Jupiter for a final speed boost toward Saturn
- Galileo is flown into Jupiter to end its mission
- Voyager 1 crosses the termination shock at about 94 AU
- New Horizons takes a gravity assist at Jupiter
- Voyager 1 crosses the heliopause at 121.6 AU
- The 2012 crossing is confirmed from plasma oscillations
- Juno enters polar orbit around Jupiter
- Voyager 1's cosmic ray subsystem is switched off
- Voyager 1's low-energy charged particle instrument due for shutdown
- Voyager 1 reaches one light-day from Earth
Related
Related because they share a subject in the Atlas — never because the text looks similar.
- Voyager 1's cosmic ray subsystem is switched off · 2025-02-25
- Voyager 1's low-energy charged particle instrument due for shutdown · 2026 (announced plan)
- Voyager 1 reaches one light-day from Earth · 2026-11-18 02:16 PST (computed)
- Juno enters polar orbit around Jupiter · 2016-07-05
- The 2012 crossing is confirmed from plasma oscillations · 2013-09-12
- Voyager 1 crosses the heliopause at 121.6 AU · 2012-08-25
- New Horizons takes a gravity assist at Jupiter · 2007-02-28
- Voyager 1 crosses the termination shock at about 94 AU · 2004-12-16