With the Moon out of the way for the next week or so, it’s a great time to seek out a dark spot with a good view of the southern sky and familiarize yourself with the three brightest outer planets.
The Sun sets at 9pm, and about thirty minutes later, Jupiter, Mars and Saturn make themselves known before any stars pop into view. The most obvious because of its location high in the southwest sky is Jupiter, named for the principal god of Roman mythology. Currently travelling through the constellation Leo, it is a great telescopic sight with its four brightest moons changing position nightly. No night is complete for an amateur astronomer unless it includes a look at the King of Planets.
Mars rises around 7:30, and can be found in the south east once the sky gets dark enough about 9:30ish. Currently about the same brightness as Jupiter, Mars was at its closest to the Earth and at its brightest for the year on May 30th. This unmistakeably red planet, half the diameter of Earth, is named for the Roman god of war. Its two known moons, Phobos and Deimos, are tiny with diameters of 22 and 12 kilometers, and orbit so close to the planet that they are virtually invisible in all but the largest of telescopes. Mars is currently found in Scorpius.
Saturn, rises just a half hour before the Sun sets, so will be quite low in the south east as the sky darkens. Also at its brightest for 2016, it’s a fifth as bright as Mars, but still brighter than any nearby stars once they show up. Saturn lies in Ophiuchus the Serpent-Bearer (off-ee-you-cuss), a huge constellation that’s little known because it’s hard to find, spell and pronounce.
Of course, Saturn’s claim to fame is its ring system made up of nine separate rings and three arcs. Although they look solid in a telescope, they are made up almost entirely of rocky particles from pebble size to ones several meters across. Some 250,000 kilometers in diameter, the rings are less than one kilometer thick.
The sixth planet from the Sun is nine times the radius of the Earth and has sixty-two known moons (five less than Jupiter). One of them, Titan, is the only moon in the solar system with an atmosphere, and another, Phoebe, orbits the planet in the opposite direction of the other moons. Saturn is named for Saturnus, the Roman god of agriculture.
These three bright outer planets will be prominently visible crossing the sky for the rest of the summer. The views through a telescope are great, but when these three are up, it’s rewarding any time you just stand there with your hands in your pockets and look up from your own back yard.
