February 2008

  • The Stars and Planets This Month

    High in the south after sunset, the brilliant star patterns of winter dominate the evening sky. Orion the hunter is making his annual journey across the sky followed by his two faithful dogs, Canis Major and Canis Minor.

    Standing in Orion’s path, but always backing away to the west as Orion advances, is Taurus the bull. Meanwhile, Gemini the twins are watching from the sideline. But Orion might want to watch behind him because Cancer the crab and Leo the Lion are hot on his heels.

    Once you familiarize yourself with the brighter stars and constellations, it makes finding planets much easier. For example, Mars is currently sitting between Taurus and Gemini, directly above Orion. Saturn is rising with Leo in the east just as the Sun is setting. This means Saturn will be visible all night long.

    Get up before the Sun for a real treat. As the month begins, Venus will be shining like a beacon in the east even with the bright glow of dawn. To the right of Venus, Jupiter is not nearly as bright but will still stand out. They will appear especially close together during the first days of the month and slowly separate over the coming weeks.

    For a challenge on the morning of the 16th, look for Mercury to the left of Venus, about the same distance away as Jupiter is to the right. Sometimes it helps to scan the sky and find Mercury with binoculars before you realize how bright it appears to your unaided eyes.

    The Moon waltzes through this picture at mid- month. On the evening of the 13th, it will be west of the Pleiades star cluster, but it will appear east of the star cluster the following night. On the 16th, the Moon will be near Mars, and on the 20th it will visit the neighborhood of Saturn.

  • Star Party - February 9, 2008

    Join us and the Barnard Seyfert Astronomical Society (BSAS) for a FREE public star party from 7:30-9:30 PM on Saturday, February 9 at Ridgefield at Edwin Warner Park. Weather permitting, we’ll get good views of Saturn and Mars. For more information about BSAS, visit www.bsasnashville.com.

  • Lunar Eclipse - February 20, 2008

    The Moon slips into Earth's shadow on the night of Wednesday, February 20, 2008 during the next total lunar eclipse. The entire eclipse will be visible from Tennessee, as well as most of North and South America, and western Europe and Africa.

    Join us at the Adventure Science Center from 7:00 to 9:30pm on February 20 to learn more about eclipses and to see the eclipse as it happens! The Barnard Seyfert Astronomical Society will be on hand with telescopes for a closer view of the Moon and other celestial sights. Even if you can't make it to ASC, go outside and have a look!

    If the weather over Nashville is cloudy or worse, the event at Adventure Science Center will be cancelled. If the weather is iffy, please check the Adventure Science Center home page or call Sudekum Planetarium's Astroline at (615) 401-5092 before traveling.

    Wait, my calendar says it's on the 21st!

    A lunar eclipse is something that can be seen from many parts of the world simultaneously. Anyone on the night time side of the Earth during the eclipse can see it happen. For events like these that can be seen over many time zones, astronomers often refer to Universal Time which used to be called Greenwich Mean Time. The eclipse does in fact take place on February 21st in Universal Time. For us in the United States, the eclipse is on the 20th, local time. If you're in the US and you go out on the night of the 21st, you'll be a day late!

    What will I see?

    As the Earth’s shadow creeps across the lunar surface, the Moon will darken and take on a reddish color. The red color is the effect of sunlight passing through the Earth's atmosphere.

    Lunar eclipses are perfectly safe to view, and no special equipment is needed, but a telescope or a pair of binoculars can add to the fun. All you really need to enjoy a lunar eclipse are your eyes and good weather.

    Eclipse Times, Central Standard Time:
    • partial (umbral) eclipse begins: 7:43 pm
    • total eclipse begins: 9:01 pm
    • total eclipse ends: 9:51 pm
    • partial (umbral) eclipse ends: 11:09 pm

    As you can see, the eclipse takes some time to happen. Don't feel that you have to watch the entire eclipse from beginning to end. Take a look every now and then to track the shadow's progress across the face of the Moon.

    Just how dark the Moon gets during a lunar eclipse depends on the amount of dust in our planet’s atmosphere. If there’s been a lot of volcanic activity or forest fires recently, the increased dust can cause the Moon to appear very dark, like an old copper penny. If there’s very little dust in the atmosphere, the Moon will appear brighter and more orange in color. The exact color and darkness of any eclipse is unpredictable. There’s no way to know ahead of time what the Moon will look like when our planet’s shadow blankets the lunar surface.

    Meanwhile, if you were standing on the Moon during the eclipse, you'd see the Earth covering up the Sun in the sky, blocking its light except for a reddish ring of light. The red light is sunlight passing through the Earth's atmosphere.

    What's a penumbral eclipse?

    In many descriptions of lunar eclipses, you'll see times listed for the beginning and end of the 'penumbral' eclipse. During this part of the eclipse, the Moon is passing through the outer edge of the Earth's shadow, the penumbra. The Moon becomes only very slightly darker. It's almost undetectable to the eyes, and most observers don't bother looking for it. The main part of a lunar eclipses is the 'umbral' eclipse, during which the Moon passes through the umbra, the dark central part of the Earth's shadow. During the February 20th eclipse, the penumbral phase begins at 6:36 pm, and ends 12:16 am on the 21st.

    To learn more about lunar and solar eclipses, visit the NASA Eclipse home page.