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The Sky This Week, 2012 February 14 - 21

Keep counting those stars!
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How many stars can you see in Orion?
Report them here!


The Moon’s waning crescent graces the pre-dawn sky this week, scudding along the bare treetops of the southern horizon among the first of summer’s rising stars. New Moon occurs on the 21st at 5:35 pm Eastern Standard Time. Look for Luna about five degrees northwest of ruddy Antares just before sunrise on the 15th. Two mornings later you’ll find her above the "Teapot" asterism of the constellation Sagittarius.

The absence of the Moon in the evening sky gives us a whole week to enjoy the bright stars of the winter sky in all their colorful glory. To encourage people around the world to do just that, the Great World-wide Star Count continues this week in an effort to get folks outside and looking up. In addition to making friends with some of the brightest stars in the sky, participants have an opportunity to engage in an exercise of "Citizen Science" by counting the number of stars they can see within the confines of Orion’s bright bounds. Created during the 2009 International Year of Astronomy, the Globe At Night program seeks to promote awareness of the night sky as a resource and to document the encroachment of artificial lighting into the grandest sight in Nature, the pristine night sky. The organizers of the program hope to secure over 15,000 observations from skywatchers around the world to document the location of dark-sky sites and to monitor the sprawl of wasteful outdoor lighting. This is the last month for us to use Orion as our reference constellation, since by the time the next dark-of-the-Moon cycle begins in mid-March the Hunter and his companions will be rapidly slipping into twilight. The method is very simple: count the number of stars you see in Orion, visit the website, compare your observations with the charts on the site, and report your findings. Feel free to make multiple observations; you’ll be doing your part for science!

The evening twilight sky and the first hour of darkness belong to the dazzling glow of Venus, who now dominates the western sky during early evening. Venus becomes easily visible as soon as the Sun sets, and keen-eyed skywatchers can now easily locate her in broad daylight in the hour or so before sunset. If you find yourself in a dark-sky location during the next several evenings try looking for shadows projected by Venus’ pale white light. The best way to do this is to wait about an hour and a half after sunset, then go out with a piece of white paper. Hold your hand between the paper and Venus and look for your hand’s ghostly shadow. Venus has not yet reached her greatest brilliancy for the year, but she is still pretty dazzling and will grab your attention no matter how bright the sky is at your observing site!

Giant Jupiter still hangs in the western sky during the early evening hours, but Venus is gradually creeping up on him. The closer Venus gets, the paler Jupiter’s glow appears despite being the third-brightest object in the nocturnal sky! Jupiter remains a treat for the small telescope, but you have to catch him in the early evening before he wheels over toward the western horizon. Look for the ever-changing configuration of his four large Galilean moons, and, if conditions are steady, look for details in his distant turbulent cloud tops.

By 8:30 pm you’ll be able to see three bright planets in the sky at the same time. Venus will be about 10 degrees above the western horizon with Jupiter about 25 degrees higher, and over in the east ruddy Mars will be about 10 degrees above the eastern horizon. The red planet is making his way rapidly into the evening sky as he closes in on opposition in a few more weeks. While this isn’t a particularly favorable opposition, it’s still worth turning the telescope to our ruddy neighbor for a peek. Mars is the only place other than the Moon in the solar system where we can glimpse features on a solid surface, and some features such as the planet’s north polar ice cap are quite easy to resolve. The planet’s pink deserts are smeared with darker features marking exposed bedrock, and "in-situ" observations by a fleet of orbiters show an amazing array of interesting landforms.

Late-night skywatchers can now see Saturn rise at around 10:30 pm, and by midnight the ringed planet may distract you from observing Mars. The planet’s rings are visible in virtually any telescope, but you might want to save observing this distant world until Mars has run his course later in the coming spring.

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