You may have heard the news about the known moons of Jupiter. We are now at 79! In the last year, the total has increased by 12. Nine of the moons are quite distant from Jupiter and travel in retrograde orbits. This means they move backward from most large objects in the solar system, clockwise rather than counter-clockwise, viewed from above the solar system. Two of the new moons are much closer to Jupiter and travel in prograde orbits (counter-clockwise). The 12th moon is tiny, quite distant from Jupiter, but it is traveling in a prograde orbit. This means that it is moving against the flow, like a skater going the wrong way relative to other skaters. Collisions are likely to happen and may destroy the moon in the future.

Come visit the Insperity Observatory on public night, the first Friday each month, from sunset to 10 p.m.:

Aaron Clevenson
Author: Aaron ClevensonEmail: This email address is being protected from spambots. You need JavaScript enabled to view it.
I am the observatory director at the Insperity Observatory in Humble ISD. I am also an adjunct astronomy professor at Lone Star College-Montgomery where I teach solar system astronomy and stars and galaxies astronomy. I am the author of the astronomy textbook, “Astronomy for Mere Mortals.” I am a past president of the North Houston Astronomy Club, and was the chair of Astronomy Day in Southeast Texas in 2015 and 2016. He is an observing program director with The Astronomical League, coordinates their Master Observer Progression Awards, and has authored six of their observing programs.