Ophiuchus is a large constellation; learn some of the mythology behind this shape in the sky in this week's "Astronomy Theater," then find out how to locate and observe the large open cluster IC4665, a colorful double star in 70 Ophiuchi, and the second closest star to Earth after the Sun and Alpha Centauri system (Barnard's star). So... open, double, close. Sounds like a door! Let Eyes on the Sky open this one for you to these great sights in the night sky.
The Moon has lots of craters - and most any small telescope can show most of them that are 20km or larger in size. But how to identify them? Take a journey this week from the easily found Mare Nubium, over the Mare Humorum, and then south along the western edge and terminator side of the Moon to find a wealth of oddly-shaped and multiple-impact craters. Among those to find and observe:
Messier 6 - also known as the Butterfly Cluster - is a fairly well known open cluster; it is bright, large, and can even be seen with binoculars from most areas. But Messier 62, a globular cluster that is technically in Scutum, is actually easier to find from Scorpius. Learn how to draw a line right to this globular, and then how to extend that line over to Sagittarius to make a flip-turn back to Messier 6.
For a free, printable star map you can use to help you find these objects, check out chart 18 on the Star Charts page.
Messier 57 is quite bright as planetary nebula are concerned, plus it is unlike mos other bright ones in a unique way. It's the only really bright one visible in most small telescopes that looks like a ring shape. Other planetary nebula such as the Dumbbell Nebula or Cat's Eye Nebula are also bright, but far different in shape, structure and appearance than The Ring.
So how to find it? Check out the video above. Messier 57 is pretty easy to locate, and is conveniently not far from one of the brightest stars in the entire sky, Vega.
Summertime brings warmer weather, shorter nights, but a good many objects to see in the night sky with telescopes and binoculars, not to mention a fair number of bright naked eye stars. Learn where to find the brighter shapes of the season from some familiar shapes like the Big Dipper / Plough, or the Summer Triangle region of the sky.
And while you're out, why not check to see how many stars you can see in the sky, and report back to Globe at Night? That helps us track light pollution across the globe.