Looking Up: King Jupiter reigns in the night
Jupiter, called the King of the Planets, is reigning over the night sky this spring (2017). The 5th planet from the Sun is by far the brightest heavenly body visible at this time, other than the Sun and Moon- and of course the Earth in broad daylight (I like to include the Earth. It’s been good to us).
Need I point it out? The next clear evening, Jupiter will not be hard to find unless of course a tree or building stands between you and the planet. Look east. Jupiter is currently positioned between six and seven degrees above the bright blue-white star Spica. Up and to the left is the very bright orange star, Arcturus.
(Jupiter’s magnitude is currently -2.5. Venus is actually brighter but it currently low in the bright dawn sky.)
Jupiter reached “opposition” on April 7, when it stood directly opposite the Sun, rising in the east at about the same time the Sun was setting in the west. Jupiter is currently visible all night long. At around midnight, the Earth has spun enough to place Jupiter due south.
A small telescope, a low power eyepiece and set up on a tripod, will easily show Jupiter as a small, squat disc- not quite round, but bulging in the middle (no puns here).
On either side you cane expect to see four “stars” that are actually its largest moons- Io, Europa, Ganeymede and Callisto. Their positions are ever changing, even on the same night if you keep coming back.
One night you might see three on one side, one on the other, or two and two, or maybe all four on one side. Sometimes one or even two moons will be missing! As they orbit Jupiter, at times one or more will have plunged into the planet’s dark shadow, be behind or right in front of the planet.
Medium to high magnification can show you details on the planet’s cloudy face- dark and light belts, spots and swirls. How well you see them, however, depends on the quality of the seeing (how steady the air is), how high the planet is in the sky, your telescope and your level of patience! If the air is unsteady or you are using too much magnification for your size telescope, you will see very little detail. Its two dark belts are fairly easy to see.
At times, the view is just incredible, and proves it as worth the wait and perseverance.
The planet is squat because the planet is spinning so fast (about once every 9 hours, 50 minutes),that centrifugal force pushes its thick, cloudy atmosphere outward.
Even binoculars, held very rigid and better yet on a tripod, will show most of Jupiter’s moons and show Jupiter as more than a point-like, bright star.
You don’t need a telescope or even binoculars, however, to enjoy the sky. Just find an open area, away from intruding street and house lights on a clear night, and take in the beauty and mystery of the stars in every direction. Learn the constellations and name of some of the stars. Find out which are the planets and watch as they slowly move night to night.
Marvel at Jupiter’s sheer brightness and how it reflects off a pond, house window or a metal roof. Ponder its vastness- more than 10 times the diameter of Earth and its great family of moons- four large and at least 63 small satellites.
There’s a NASA spacecraft named Juno orbiting Jupiter right now, making amazing discoveries for science, but none more wonderful than what just “looking up” can mean to you in your heart.
Earth, by the way, has one moon, and it is “new” on April 26.
Keep looking up!
Peter Becker is Managing Editor at The News Eagle in Hawley, PA. Notes are welcome at firstname.lastname@example.org. Please mention in what newspaper or web site you read this column.