Venus, Mars say goodbye while Saturn says hello
July stargazing this year kicks off with the first full "supermoon" of the year on Monday.
The term supermoon has always bugged me. Its origin comes from astrology rather than the actual science of astronomy. Nonetheless, it's become a media darling. A supermoon is generally defined as a full moon that's a little closer to Earth than average.
Because the moon's 27.3-day orbit around Earth is an ellipse and not a perfect circle, the moon has maximum and minimum distances from Earth in each orbit.
The full moon this month, and three other full moons this year, will be a little closer to Earth than average. As a result, this month's full moon will be slightly larger and brighter than usual. I certainly wouldn't describe the difference as "super," though.
After the first week of July, stargazing will improve with most of the bright moonlight out of the early Butler evening sky.
The bright planet Venus is still hanging low in the west in the early evening during the first half of the month. Just to the upper left of Venus is the much fainter planet Mars. Both planets are leaving the evening sky this month.
Every night in July, Venus and Mars will start the evening lower and lower in the western sky, and by the end of the month, they'll be lost in the evening twilight.
Before that happens, you should get a last look at them through your telescope. Honestly, it's not much of a view. Mars is more or less an orange-red dot because it's so far away from Earth now.
Venus is a little more interesting. Even being completely cloud-covered, it resembles a crescent moon. Both Venus and Mercury go through phase cycles like our moon because they orbit the sun inside the Earth's orbit.
Before Venus checks out of the evening sky, it will have a super close encounter with the moon. On July 19 and 20, the new crescent moon will hang close to the planet named after the Roman goddess of love.
The first actual star to pop into view in June is Arcturus in the high southwest sky. It's considered a red-giant star, nearing the end of its stellar life. Even to the naked eye, Arcturus has an orange-red glow to it.
Arcturus is the brightest star in the constellation Bootes the Herdsman, which resembles a giant kite more than a herdsman. Arcturus marks the kite's tail.
Not far away from Bootes is the faint constellation Hercules the Hero. Within its boundaries is one of the best things you can view through a telescope, the Great Hercules Cluster. It’s also known as Messier object 13, or M13, a spherical cluster of at least a half million ancient stars over 25,000 light-years away. Just one light-year equals nearly six trillion miles!
High in the eastern heavens, you should be able to easily see the bright stars that make up the "Summer Triangle." Each of these stars is the brightest in their respective constellations, Vega in Lyra the Lyre, Altair in Aquila the Eagle, and Deneb, the brightest shiner in Cygnus the Swan. One of my favorite little constellations, Delphinus the Dolphin, is not far from the star Altair. It really looks like a little dolphin!
In the low southern sky is the classic summer constellation Scorpius the Scorpion, with the enormous red supergiant star Antares marking the heart of the beast. It's over 600 light-years away. Antares is so large that if it took the place of the sun in our solar system, the planets Mercury, Venus, Earth and Mars would live inside Antares.
For you late-night stargazers, Saturn is on the rise not that far from Sagittarius, just above the eastern horizon by midnight. This is Saturn's first appearance in the evening sky before midnight since February.
Unlike Mars and Venus in the early evening this month, Saturn is one of the best telescope targets in the sky, even for smaller telescopes. You can easily see Saturn's ring system and even some of its moons that resemble little stars buzzing around the ringed wonder of our solar system.
Saturn's largest and brightest moon, Titan, has a thick atmosphere. If you can stay up late enough, try to view Saturn through your telescope after 1 a.m., allowing Saturn to rise above the blurring effects of our atmosphere near the horizon. On Friday, the waning full-gibbous moon will rise just below Saturn. In August, Saturn will rise earlier and, and get much closer to Earth.
Enjoy the warmer summer night skies of July!
Mike Lynch is an amateur astronomer and retired broadcast meteorologist for WCCO Radio in Minneapolis/St. Paul. He is the author of "Stars: a Month by Month Tour of the Constellations," published by Adventure Publications and available at bookstores and adventurepublications.net. Contact him at mikewlynch@comcast.net.