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The Sky This Week, 2017 April 25 - May 2

Celebrate Astronomy Day!
Celebrating astronomy on the National Mall

The Moon waxes in the evening sky this week, wending her way through the departing winter stars as she makes her way to First Quarter, which occurs on May 3rd at 2:47 am Eastern Daylight Time. Look for Luna’s crescent near Mars and the bright star Aldebaran on the evenings of the 27th and 28th.

April 29 is International Astronomy Day, one of two days set aside each year to raise awareness of the night sky and the fascinating objects that can be found there. It is a great chance to introduce people to amateur astronomy, and to show that even non-professionals can make important and useful contributions to the study of the Universe. When you consider that amateurs have the exact same "specimen" to explore at their leisure as the professionals do, it’s no wonder that they often find things that major observatories overlook. Amateurs are responsible for most of the routine observation of the planets, and until the advent of large automated sky surveys discovered most of the comets, novae, and supernovae that have graced our skies over the past decades. You don’t need to have an advanced degree to appreciate the craters of the Moon, the cloud belts of Jupiter, the rings of Saturn, or the soft glow of distant galaxies in the eyepiece. It’s all above our heads on every clear evening; all you need is curiosity and a dark sky to enjoy it. Many of the local astronomy clubs and planetariums will have programs for your enjoyment on the 29th. We have a link to many of these organizations on our website. Find one near you and join them for an evening under the stars.

May 1st is May Day, a holiday that’s still observed widely in many European countries, especially Great Britain, Germany, and regions with a strong Celtic tradition. Its origin goes back to Roman times and a spring fertility festival known as Floralia, which was traditionally observed on April 27th. Germanic people in pre-Christian times observed April 30 as Walpurgisnacht, and the ancient Celts celebrated Bealtaine on the same night. These traditions included bonfires, dancing, and general merrymaking to celebrate the traditional beginning of summer that fell on May 1st. As Christianity swept across Europe the Pagans adapted their festivals to the new religion but maintained many of their celebratory traditions.

As we wait for April to turn into May, we can still find ruddy Mars lingering in the western twilight sky. The red planet is now gradually losing ground to the approaching Sun, and if you catch him in the telescope eyepiece you’ll see little more than a small pinkish dot. This week he moves between the Pleiades star cluster and the bright star Aldebaran in the constellation of Taurus, the Bull. Aldebaran is slightly brighter, but the two objects share the same warm hue. The crescent Moon will pay a visit on the evenings of the 27th and 28th.

Jupiter is in prime viewing position in the evening sky. The giant planet is well up in the east as evening twilight fades, and you’ll have most of the night to study his ever-changing cloud belts and dancing Galilean moons with a telescope. If you’re at an Astronomy Day event you should be able to see the famous Great Red Spot rotate off the planet’s disc between 9:00 and 11:00 pm. The planet’s moons will all be visible as well.

Look for yellow-hued Saturn near the meridian in the south at around 5:00 am, just as twilight begins to brighten the sky. He is perched between the familiar summer constellations of Scorpius and Sagittarius and is the brightest object in this part of the sky. His bright rings should be easy to see in virtually any telescope.

Venus should be easy to spot in the eastern sky in the gathering glow of morning twilight. She will spend the rest of the year greeting the rising Sun, so early risers should get used to having her for company.

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