The sky in July — Saturn joins Jupiter
Early stargazing in July is always a wonderful time. Even though you can’t get started until late in the evening you can catch the wonderful heavenly show without freezing! Stargazing this July is extra special because Saturn and Jupiter, the biggest planets in our solar system, have joined our summer southwestern Minnesota night skies.
During evening twilight this month, a super bright “star” will pop out in the south-southeastern sky. That’s actually the planet Jupiter, which reached its closest approach to Earth last month and is still relatively close by at just over 403 million miles away. That’s considered close for the behemoth that is our solar system. To the lower left of Jupiter less than an hour after sunset you’ll see another bright star-like object, not quite as bright as Jupiter, rising above the southeast horizon. That’s Saturn, the ringed wonder of the solar system, nearing its closest approach to Earth for 2019.
With even a small telescope both Jupiter and Saturn have much to offer. On Jupiter you can easily resolve the disk of the 88,000-mile wide planet, and you may be able to see some of the cloud bands of Jupiter. You may even see Jupiter’s famous Red Spot, a huge storm about three times the diameter of Earth. In reality it’s more of a light pink than red. It’s not always visible because Jupiter spins on its axis once every nine hours and 50 minutes, and the side with the Red Spot is not always facing Earth.
For sure you’ll see up to four of Jupiter’s largest moons that resemble tiny stars on either side of Jupiter. They’re constantly changing their position relative to the planet as they orbit around Jupiter in periods of two to 17 days. Some nights one or more of Jupiter’s moons will be absent since they could be behind the big planet or camouflaged in front of it. I’ll have more on Jupiter’s moons next week in Starwatch.
Saturn is cool through even a smaller telescope. You can clearly see its more than 140,000-mile diameter ring system and the division between the actual planet and ring system. As wide as the ring system is, it’s extremely thin with a maximum thickness of only about a half a mile. You might even see some of Saturn’s moons.
Even without Jupiter and Saturn, the stars and constellations of July are wonderful. The brightest actual star in the sky this month is Arcturus. At nightfall it’s perched high in the western sky at the tail of a giant kite. That kite is more formally known as the constellation Bootes, the hunting farmer. In the eastern heavens, you’ll see the prime stars of summer on the rise. The best way to find your way around that part of the sky is to locate the “Summer Triangle” made up of three bright stars, the brightest in each of their respective constellations. You can’t miss them.
The highest and brightest star is Vega, the brightest star in a small constellation called Lyra the Lyre. The second brightest star on the lower right is Altair, the brightest in Aquila the Eagle. The third brightest at the left corner of the summer triangle is Deneb, the brightest star in the tail of Cygnus the Swan. Cygnus is known as the “Northern Cross” because that’s what it really looks like.
In the north look for the Big Dipper hanging from its handle in the northwest, along with the fainter Little Dipper standing on its handle. The moderately bright star Polaris, otherwise known as the North Star, is at the end of the Little Dipper’s handle.
In the south-southeastern sky, just to the lower right of Jupiter, is the classic constellation Scorpius the Scorpion that actually resembles a scorpion. Since we live in the far northern latitudes, though, the tail of the beast never rises above the horizon. Not far away in the lower southeast, just to the left of Saturn, is one of my favorite constellations — Sagittarius the Archer. It’s supposed to be a half-man, half-horse shooting an arrow, but it looks much, much more like a teapot!
Mike Lynch is an amateur astronomer and professional broadcast meteorologist for WCCO Radio in Minneapolis/St. Paul. He is also the author of “Stars: a Month by Month Tour of the Constellations,” published by Adventure Publications and available at bookstores and at adventurepublications.net.