Swirls, storms and belts, oh my! NASA released several new photos recently from the Juno spacecraft’s tenth close flyby of Jupiter on Dec. 16, 2017. Juno travels in a highly elongated orbit around Jupiter once every 53 days. For just two hours during that time, it loops in close to the planet’s polar regions to grab data and take astounding images. That closest point is called perijove, when the probe skims just 2,100 miles above Jupiter’s cloud tops while zipping by at 129,000 miles an hour (57.8 km/sec).
The images feature a new view of Jupiter’s north polar belt region and a unique, wide-angle perspective (top) on the planet’s cloud belts. It’s hard to take our eyes off the swirling storm clouds that festoon so much of the planet. They look so Van Goghian. We see only Jupiter’s cloud tops. Whatever solid surface the planet might have lies deep below thousands of miles of clouds and thousands more of liquid metallic hydrogen, a weird form of hydrogen that’s so highly compressed by the weight of all the material above it that it transforms into a liquid that can conduct electricity.
Upper level clouds in Jupiter’s atmosphere are made of ammonia ice crystals (it’s cold out there half a billion miles from the sun) with deeper layers composed of ammonia laced with sulfur and even water ice. You can see the this bizarro world for yourself every morning at dawn. Jupiter rises around 2 a.m. in late January and stands high in the southeastern sky around 6-6:30 a.m. local time. It’s the brightest object in that direction — can’t miss it. A 3-inch (75mm) telescope will show the most prominent cloud belts as dark streaks across Jupiter’s pale yellow disk.
Skywatchers finally have the International Space Station (ISS) back for easy evening viewing. It’s always fun to watch the station pass over your location and picture the (currently) six astronauts on board conducting experiments, eating dinner or lolling around in the cupola staring back at Earth. The ISS speeds around the Earth about every 90 minutes at over 17,000 mph and looks like a very bright star moving from west to east.
You can easily get predictions for passes at Heavens Above. Find your city then click the ISS link for a table showing times, altitudes, etc. If you click on a particular date, a map pops up showing its path across the sky. When a path is incomplete, it means the satellite disappears in eclipse — it moves into Earth’s shadow. You can also use NASA’s Spot the Station website. Type in your town’s name then click the yellow circle to zoom into the pinned locations. Click a blue pin for sighting opportunities.
ISS viewing opportunities extend through mid-February.