Scorpius' stars put sting in summer sky

Greetings, stargazers.

The late afternoon monsoon clouds finally parted and made for a few good observing evenings recently. Unfortunately for me, a couple of those nights were interrupted by smoke from the Toe Fire on Sleeping Ute Mountain. Trying to gather enough light for a color photograph of any deep sky object is challenging enough without interference from orange haze. Maybe the sky was just jealous of the river's new color.

The peak of the Perseid meteor shower was early this morning. These meteors appear to radiate from the constellation Perseus (thus the name) and result from the Earth hitting the trail of dust and debris that follows the orbit of the comet Swift-Tuttle.

The total shower duration is about a week, so even if you missed the show last night, the next couple of nights should have many more meteors than you would see on an average night. Since the new moon is Thursday night, it should be a good, dark night for observing.

This month

Venus, recently the evening star, is finally setting before the sun, and will make its next appearance as the morning star by the end of the month.

If you want a challenge when the sun is setting, you might glimpse Mercury low on the western horizon before it gets totally dark. It will be there for the next few days.

The biggest planetary treat is Saturn. The rings are tilted enough now that even some good binoculars can show you a tiny football shape. With a small telescope the rings will be well separated from the planet. If you have slightly more magnification and resolution available, you should look for the Cassini Division, a gap in the rings about two-thirds of the way out.

Just to the east of Saturn is the prominent summer constellation Scorpius. Made up of mostly bright stars, it is, I think, one of the few constellations that actually looks like its namesake. The bright orange star Antares, which means Rival of Mars, is at the heart. The long curved tail ends in a pair of stars for the stinger. The tail is very near the brightest part of the Milky Way.

There are several mythological stories about the scorpion; most involve Orion. In one version, the scorpion stung and killed Orion, but before Orion died, he killed the scorpion. These mortal enemies were then placed on opposite sides of the heavens so they would never be in the sky at the same time.

Slightly more than one degree to the west of Antares is the globular cluster M4. Because of its proximity to Antares, it is one of the easiest globulars to find. It should be visible in binoculars as a tiny puff ball.

To the east of the scorpion's stinger is the open cluster M7. It is visible to the naked eye as a faint fuzzy patch, and binoculars will show a nice, rich grouping of stars.

Upcoming stargazing opportunities include events Friday at Chimney Rock and Saturday at Mancos State Park. The Chimney Rock program requires a small fee and includes a pre-dusk archaeoastronomy talk.

Charles Hakes is an assistant professor in the physics and engineering department at Fort Lewis College and is director of the Fort Lewis Observatory. Reach him at hakes_c@fortlewis.edu.

Useful links

Scorpius: https://en.wikipedia.org/wiki/Scorpius

Astronomy picture of the day: http://apod.nasa.gov/apod/

An astronomer's forecast for Durango: www.cleardarksky.com/c/DrngoCOkey.html?1

Old Fort Lewis Observatory: www.fortlewis.edu/observatory

Four Corners Stargazers: http://groups.google.com/group/Four-Corners-Stargazers