13 October 2022
Today is Thursday, Thor’s Day, or Jove’s Day. We’ll celebrate with some quick facts about Jupiter.
The Romans named the fifth day of the week dies Jovis (“Jove‘s Day”) after the planet Jupiter. In Germanic mythology, Jupiter is equated to Thor, whence the English name Thursday for the Roman dies Jovis.
— From Wikipedia: Jupiter
Jupiter was big in the news last month when on 27 September 2022 the planet was at its closest, brightest and best in 70 years. On that date the Earth flew between Jupiter and the Sun, putting Jupiter in opposition and in bright sunlight as it rose at sunset.
Three days later it rose after sunset so the sky was dark showing off Jupiter’s four largest moons, the ones first seen by Galileo in 1610.
Timelapse photography allows us to see the Galilean moons orbiting Jupiter as NASA’s Juno spacecraft approaches. These are only four of the 80 known satellites of Jupiter, most of which are less than 10km (6.2 miles) in diameter. 80 moons!
Moons Io and Europa have sparked a lot of interest.
Jupiter doesn’t have rings like Saturn, but it ought to. Why not?
Because it’s bigger, Jupiter ought to have larger, more spectacular rings than Saturn has. But new UC Riverside research (21 July 2022) shows Jupiter’s massive moons prevent that vision from lighting up the night sky.
And finally, Thursday is a good day to feel jovial. According to Wikipedia, the older adjectival form jovial, employed by astrologers in the Middle Ages, has come to mean “happy” or “merry”, moods ascribed to Jupiter’s astrological influence.
(images from Wikimedia Commons; click on the captions to see the originals)