Astronomy Notes for May 2011
May 3 New Moon
May 5-6 Aquarid meteor shower
May 17 Full Moon
Ever so often big, dirty snowballs (otherwise known as comets) come into our solar system; they circle the sun and then head back out beyond the planets. When a comet flies close to the sun, it begins to melt, and some of its dirt and debris falls off, leaving a path rather like Hansel and Gretel’s trail of breadcrumbs; most of the particles are very small—the size of a grain of sand or a pea. When the earth crosses the comet’s trail and those particles hit our atmosphere, we see a streak of light crossing the sky. Some are rather spectacular and colorful. We call these streaks meteors or, sometimes, shooting stars, although they really are not stars. If you are going out to watch the meteor shower, it is a good idea to lie down on a blanket so that you can see a large portion of the sky at one time. You might want to keep count of how many meteors you see and how long you are outside. There may only be 10 to 15 meteors per hour, but sometimes there will be as many as 50 to 100. The meteor shower often peaks late at night or just before dawn, which is the best time to go out to look for them. The reason this month’s shower is called the Aquarid Meteor Shower is that the meteors seem to originate in the same area that we find the constellation Aquarius.
When to Stargaze
It is best to go out and see the night sky when there is no moon because the moon is so bright it makes the rest of the sky hard to see. Each day the moon rises, on an average, 50 minutes later than the day before. New moon occurs when the sun and the moon rise and set at the same time, and the moon is hidden in the bright sunlight—we do not see the moon that night at all. Full moon occurs when the sun is on one side of the earth and the moon is on the opposite side; the moon rises in the east in the evening when the sun is setting in the west, and it sets in the west when the sun is rising in the morning in the east—it is visible all night long. Unless we want to study the moon, we usually try to avoid stargazing on nights when the moon is large and bright. That is why most amateur astronomers do evening stargazing during the 2 weeks after full moon.
There are a few planets that are visible in our May sky, but most of them are very close to the sun, making them hard to see. The easiest one to find right now is Venus. If you go out a little while before the sun rises, you will see a very bright “star” rising in the east—it is Venus. If you take a pair of binoculars and steady them on a window sill, porch rail, or tripod, you should be able to tell that this bright object is not a star—it will look white, roundish, and “flat”. Venus goes through the same stages as the moon—waxing, full, waning, and crescent. Right now Venus is just a little smaller than “full moon”.
Saturn is in the night sky right now. It is in the constellation Virgo which has only one bright star, Spica. This link might help you find Saturn in the night sky: http://earthsky.org/tonight/follow-the-arc-to-arcturus . If you look at Saturn with your binoculars, be sure to get them as steady as you can, and you just might be able to see what looks like “ears” on both sides of the planet—those are Saturn’s rings.
Download a sky map
Area Night Sky Activities
Iowa County Astronomers Club meeting is on May 6th in Dodgeville, WI.
Learn more here: http://icastro.org . Everyone is welcome!
Starsplitters of Wyalusing State Park near Prairie du Chien, WI
Members’ meeting is on May 12th at 7:30. You are welcome to visit! There will be free summer programs on May 14th and 28th (you do need a state park sticker to get into the park). There will be an inside program rain or shine at 8:30. If the skies are clear, we will set up our telescopes and introduce you to the night sky!
http://www.wyalusing.org/ Click on “Star Gazing”.
For more information you can contact JeaninWisconsin- at – yahoo – dot -com