It's A Volcano, But Not As We Know It - Astronomers Study Largest Active Volcano In Solar System
MAY 16, 2017 @ 04:43 PM
David Bressan , CONTRIBUTOR
In his notes for January 7, 1610, Italian physicist Galileo Galilei (1564–1642) wrote "when I was viewing the heavenly bodies with a spyglass, Jupiter presented itself to me; and because I had prepared a very excellent instrument for myself I perceived that beside the planet there were three little stars, small indeed, but very bright." Later he discovered even a fourth moon, orbiting around Jupiter. Apart from their existence, until the 19th century little was known of the four largest moon of Jupiter, named Io, Europa, Ganymede, and Callisto. In 1805 French physicist Pierre-Simon (Marquis de) Laplace (1749-1827) calculated, based on the observed orbits, some basic parameters, like sizes and densities, of the four moons, nowadays also known as Galilean moons. With first telescopic observations, it was soon found that Io had the reddest surface in the Solar System. Also, it was noted that Io displays an unusual brightness in infrared, suggesting that the surface was very hot, exceeding in some areas 620°F. But only the images taken by the spaceship Voyager I revealed Io’s secrets.
More:
https://www.forbes.com/sites/davidbressan/2017/05/16/its-a-volcano-but-not-as-we-know-it-astronomers-study-largest-active-volcano-in-solar-system/#1ae48e366b71
