With a moonless night on tap early this week, deep-sky delights, a comet heading for Mars, and a blue giant at its best offer themselves up for sky-gazers.
Spying Sagittarius. With a new moon on Monday, August 25, dark skies offer a great time to check out the Milky Way steaming out of a giant “teapot” in the sky.
Look toward the low southern horizon on any clear night this week and catch sight of a mythical beast, the centaur archer Sagittarius, thanks to an easy-to-spot pattern of stars. Never rising high in the summer night sky for those in the northern latitudes, the zodiacal constellation Sagittarius is easy to track down—even from city suburbs—thanks to its pattern of stars that mark a giant celestial teapot.
While tracing the entire constellation might take some imagination, it’s pretty easy to trace the familiar form of a star-studded teapot, complete with handle, lid, and spout. To find Sagittarius, use Antares, the brightest star in the southern night sky, as a guidepost, and look due east (or left) of this brilliant orange star. And don’t forget to take out those binoculars or a small scope and cruise around the teapot for a plethora of deep-sky treasures such as the gas clouds and star clusters studding the entire region.
Look carefully above the spout of the teapot and you will notice what looks like cosmic “steam” wafting up into the heavens. That in fact is the ghostly glow of millions of stars that make up the Milky Way, our home galaxy.
Comet Siding Spring. Sky-watchers using binoculars and telescopes in the Southern Hemisphere can preview comet Siding Spring (C/2013 A1). The icy visitor will brush by Mars later this fall.
Starting Thursday, August 28, the comet will pass by a series of deep-sky wonders and make for a fine astrophotographic opportunity for the more experienced sky hounds.
First, on Thursday evening, the comet will pose with the globular cluster NGC 362, then on Friday, August 29, it will slide next to the Small Magellanic Cloud, one of our Milky Way’s companion dwarf galaxies.
Finally, Siding Spring will pay a visit to the bright globular cluster called 47 Tucanae.
Neptune peaks. On Friday, August 29, Neptune, the eighth and last major planet in the solar system, reaches opposition. That means the gas giant is opposite the sun in our sky, so it will be visible all night long. Opposition also marks the planet’s closest approach to Earth, which makes it brighter to our eyes than at any other time.
Over the next few weeks, Neptune will reside some 2.7 billion miles (4.3 billion kilometers) away from Earth. That is so distant that reflected sunlight off its icy cloud tops takes nearly four hours to reach us.
It’s this distance, however, that makes it a bit of challenge to track down. At magnitude 7.8, it is out of reach of the naked eye, but can be glimpsed with binoculars or a small telescope using high power.
Neptune lies in the constellation Aquarius, less than one degree northeast of the 5th magnitude star, Sigma Aquarii. Look for a tiny blue-gray disk among the background of faint stars in the region.
Moon meets Spica. Also on Friday, just as dusk sets in, look for the razor-thin crescent moon posing just above Spica low in the southwest.
The cosmic duo will appear only 2 degrees apart, a little more than the width of your thumb at arm’s length.
Trio of worlds. About a half hour after sunset on Sunday, August 31, the moon rises higher in the sunset sky and joins a planetary pair for a pretty photo opportunity.
Look for a stunning triangular formation consisting of Mars, Saturn, and the waxing crescent moon hanging halfway up the southwestern sky as dusk sets in.
What a way to end the day!