July star map

One of the great ironies of the year is the fact that in the heat of the summer in the northern hemisphere, the Earth is much farther away from the sun than it is in the winter.

This year the Earth is farthest from the Sun on Monday, July 6. Since the Earth’s orbit around the sun is not a perfect circle, its closest approach to the sun is in early January, known as perihelion. Its farthest distance is in early July, known as aphelion. The sun is around 3 million miles farther away at aphelion than at perihelion. The tilt of the Earth’s axis has much, much more to do with the seasons!

Early evening Butler skies in June featured quite a planet show with Jupiter and Venus closely passing each other in the western sky. Mercury also made a nice appearance. Mercury is no longer available in the evening, and Jupiter is barely visible early this month, slipping below the west-northwest horizon no later than an hour after sunset.

Venus is still with us though and is the brightest starlike object in the sky this month, popping out in the low western twilight very soon after sunset and slipping below the horizon not long after evening twilight ends.

As bright as Venus is, don’t expect to be wowed with what you see of it through your telescope. Shrouded completely in a thick, poisonous cloud cover, its surface is obviously impossible to observe.

What you will see, though, is that Venus goes through phases just like our moon because its orbit around the sun lies within Earth’s orbit. Venus is in the shape of a gibbous moon as July begins. By the end of July, it looks like a first-quarter half-moon. The phases are best seen during evening twilight. Once it’s dark, the glare of Venus makes phase seeing quite challenging.

This Thursday, July 9, Venus finds itself less than one degree above the moderately bright star Regulus. You certainly won’t need binoculars to see Venus, but you may need them to spot Regulus. On Thursday and Friday, July 16 and 17, the waxing crescent moon will be photobombing Venus. I’ll have more on that next week.

If you’re a super early riser — which is very necessary this time of year — you can wake up to the lovely planet Saturn fairly high above the southeastern horizon just as morning twilight begins to fade in. It’s certainly not a super bright planet, but it’s the brightest starlike object in that part of the sky.

Unlike Venus, Saturn is a wonderful target for telescopes. Even with a small scope you should easily be able to resolve Saturn’s wonderful ring system and many of Saturn’s moons that swarm the planet. This coming October we’ll get a really good look at Saturn as it enters the early evening sky and reaches its closest approach to Earth this year.

The first actual star to pop out in the evening heavens 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 sights you can see through a telescope: the Great Hercules Cluster. It’s also known as Messier object 13 or M13. Use the July star map to find it. M13 is a spherical cluster of at least half a million ancient stars over 25,000 light-years away. Just 1 light year equals nearly 6 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 its respective constellation: Vega in Lyra the Lyre; Altair in Aquila the Eagle; and Deneb, the brightest star 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 replaced the Sun in our solar system, the planets Mercury, Venus, Earth and Mars would orbit within it. Talk about global warming!

Another of my favorite summer constellations is Sagittarius the Archer, fully rising behind Scorpius after 10 p.m. According to Greek mythology, it’s a centaur shooting an arrow. If you’re unfamiliar with mythological centaurs, they’re creatures with the upper body of a human and the lower body and legs of a horse.

Good luck seeing that when you’re stargazing! With much less imagination, though, the brightest stars of Sagittarius roughly outline a bow and arrow, but most stargazers see it as a giant celestial teapot.

If you’re lucky enough to observe from the really dark skies of the countryside, look for the bright but ghostly ribbon of light that stretches across the eastern half of the sky from the constellation Cassiopeia to Sagittarius. That’s the Milky Way band, the combined light of billions and billions of distant stars in the central plane, the thickest part of our home galaxy, where most of the stars reside.

The center of our galaxy is in the direction of Sagittarius, just above the spout of the teapot. Our view of the downtown Milky Way would be a whole lot brighter than it is, but thick clouds of interstellar dust and gas are in the way.

Next month we’ll have the Perseids, one of the best meteor showers of the year. In the meantime, enjoy the warmer summer night skies of July!

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. Contact him at mikewlynch@comcast.net.