Jupiter Reclaims Title of Planet With the Most Moons

[Judi Lynn]

After the discovery of 12 new moons, the gas giant now has 92 known natural satellites—and scientists expect to find more

Will Sullivan

February 8, 2023



An enhanced-contrast image of Jupiter and its moon Ganymede taken by NASA's Cassini spacecraft in 2000. NASA / JPL / University of Arizona

Astronomers discovered 12 additional moons of Jupiter, raising its total number of known natural satellites to 92. The gas giant now holds the record for the most known moons of any planet in the solar system—for the time being, at least.

Saturn is the current runner-up with 83 known moons, and prior to this discovery, it had been the reigning leader for moon count since 2019. But if scientists could detect all moons at least three kilometers wide, “Saturn would have more moons than all the rest of the solar system,” Brett Gladman, an astronomer at the University of British Columbia in Canada who was not involved in the recent discoveries, says to Sky & Telescope’s Jeff Hecht.

Sometimes called the “king of planets,” Jupiter is more than twice as massive as the rest of planets combined. While people have known of Jupiter’s existence for at least a couple thousand years, the first detailed observations of the fifth-closest planet to the sun are credited to Galileo Galilei in 1610. He also discovered four of Jupiter’s moons at this time.

Over the next 400-odd years, further observations increased that tally to 80 known moons. Then, astronomers spotted these 12 additional candidates using telescopes in Hawaii and Chile in 2021 and 2022.

More:
https://www.smithsonianmag.com/smart-news/jupiter-reclaims-title-of-planet-with-the-most-moons-180981585/

[progree]

1. "While people have known of Jupiter's existence for at least a couple thousand years"

i can't make any sense out of that. Aside from the sun and moon, it's the 2nd brightest object in the sky (2nd to Venus, and usually brighter than Mars, and all of the above brighter than the brightest star, Sirius). So it's not like it hasn't been astoundingly visible for eons.

So are they talking about when it was realized, like Venus and Mars and Mercury and Saturn, to not be like the stars in that they wandered around the skies relative to the stars, while the stars kept the same fixed positions relative to other stars ... that was known many thousands of years ago I'm sure.

Here's some stuff on what some Greeks thought --
https://farside.ph.utexas.edu/teaching/301/lectures/node151.html

A second Greek philosopher, Aristarchus of Samos (310-230BC), proposed an alternative model in which the Earth and the planets execute uniform circular orbits around the Sun--

I suppose that's roughly a couple thousand years ago...