The Sky This Week, 2014 May 20 - 27
|Saturn, 2014 May 19, 02:39 UT
The Moon wends her way through the dim autumnal constellations this week, greeting early risers as she wanes from Last Quarter to a slender crescent in the pre-dawn sky. New Moon occurs on the 28th at 2:40 pm Eastern Daylight Time. Luna doesn’t encounter much in the way of bright company until the 25th, when she may be found just over 2 degrees west of dazzling Venus in brightening morning twilight.
The waning crescent Moon shouldn’t be a factor for skywatchers in most of North America on the night of the 23rd and the early morning of the 24th. With a little luck and clear skies we should have a ringside seat to see a brand-new meteor shower during this time. We can thank a small, dim comet known as 209P/LINEAR for this potentially spectacular show which should peak somewhere between 2:00 and 4:00 am on Saturday morning here in the Washington area. The comet was discovered in 2004 in a roughly 5 year orbit that takes it out to the vicinity of Jupiter, whose large gravity field controls the comet’s destiny. The comet itself will pass about 5 million miles from Earth on the 29th, but on Saturday morning we should plow headlong into a stream of dust that sputtered off the comet’s nucleus at an unseen return from some 200 years ago. Various meteor experts predict that a single observer at a dark-sky site should see anywhere from 30 to 200 meteors per hour during the peak of activity. Unlike the more famous Perseids or Leonids, these “shooting stars” will be quite slow, actually looking like a star falling from the sky. The shower radiant will be in the obscure northern constellation of Camelopardalis, the Giraffe, to the left of Polaris, the North Star. The best way to enjoy the show is to set up a lawn chair with your feet pointing to the northwest horizon, bundle up against the cool night air, grab some coffee, and look up. If the predictions hold you could be in for quite a treat.
For those of you who like to stargaze in the early evening, the elusive planet Mercury is now putting on his best evening show of the year. You’ll find the fleet planet about 10 degrees above the west-northwest horizon at around 9:15 pm. By this time the sky should be dark enough to see him with the naked eye, but binoculars are often a big help when trying to locate him the first time. He reaches his greatest elongation from the Sun on the 25th.
Jupiter dominates the twilight and early evening hours in the western sky. You’ll have no trouble spotting the giant planet as the sky darkens, and as soon as he becomes visible you should get him centered in the telescope eyepiece. Jupiter will sink fairly quickly toward the horizon and its attendant turbulent air, but you still have a bit of time to look for his four bright Galilean moons and atmospheric cloud belts. As the sky darkens, look above Jupiter for the twin stars of Gemini, Castor and Pollux. Point your telescope at Castor (right-most of the two) and you’ll be rewarded with a view of what appears to be a very nice double star. In reality, the Castor system consists of at least six stars, but we can only see two without spectroscopic equipment.
Mars now crosses the meridian at the end of evening twilight. His ruddy glimmer is still quite eye-catching, and this is further embellished by the view in a small telescope. Modest-sized instruments will show a small polar ice cap along the limb of his disc, and when the air is steady you may be able to discern some of his dark surface features. The red planet now shows a distinct gibbous phase which should be easy to see in any telescope.
Saturn is now enjoying the prime-time portion of the current apparition. There is no mistaking this far-flung world for any other object in the sky. His distinctive ring system may be seen in a steadily-held pair of binoculars, and every increase in the size of your optics will reveal more detail in these mysterious appendages. A three-inch scope should reveal the dark gap in the rings known as Cassini’s Division, and in six-inch or larger instruments you should be able to see the globe of the planet peeking through the division where the rings cross the disc’s southern hemisphere. You should also notice the subtle color changes in the rings on either side of this 5000 kilometer gap.
Venus continues to linger in the morning twilight sky, staying just ahead of the Sun as she moves northward along the ecliptic. You’ll have a great photo opportunity before sunrise on the 25th, when the dazzling planet is close to the waning crescent Moon.