| April 2004 | |
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 Download this month's star chart! |
So Many Planets...
This month you'll be able to see four, maybe even five, planets with the naked eye all at the same time!
Go out about 8:00 pm. Most obvious of the five are Venus and Jupiter. Venus appears low in the west after sunset and is the brightest thing in the sky apart from the Moon. Meanwhile, the second-brightest object, Jupiter, is high in the east, just below Leo the Lion.
Saturn can be located by using the two brightest stars of Orion the Hunter. Draw an imaginary line from Rigel to Betelgeuse, and extend that line until you reach the next bright object near the feet of the Gemini the twins. That's Saturn!
Returning to the west, near Venus, you'll find Mars. Mars isn't nearly as bright as it was last summer, but it's still visible, just above and to the left of Venus. Be careful not to mistake it for Aldebaran, the bright orange star that marks the eye of Taurus the Bull. Aldebaran will be just a bit brighter than Mars.
What about that fifth planet? During the first few days of April (and the last week of March) you may be able to catch a glimpse of elusive Mercury just after sunset, low in the west. You'll need a very low western horizon, clear of trees or buildings. Even then, it can be tricky to see. Scanning with binoculars first may make it easier to spot with the naked eye. Don't wait too long! Every day it gets harder to see. By the 5th or 6th, it will be lost in the glare of sunset.
Even though Mercury will be long gone, you simply must go outside Friday evening, April 23, because Venus and Mars will be closely attended by a pretty crescent Moon with Saturn and Jupiter watching from a distance.
So Many Comets...
A comet is a ball of ice and dust, several miles across. Occasionally, a comet's orbit will bring that "dirty snowball" into the inner solar system where solar heating causes it to melt and give off gas and dust. Sunlight reflecting off this material sometimes creates a spectacle visible from Earth.
On average, there is one bright, naked-eye comet every ten years; however many readers will recall Comet Hyakutake from 1996 and Comet Hale-Bopp in 1997. It should be too soon for us to see another!
Planetarium people are hesitant to hype such possibilities because comets are among the most unpredictable things in astronomy. In 2001, Comet NEAT was discovered and in 2002, Comet LINEAR was discovered; both by automated sky surveys. Current predictions indicate that Comet NEAT will be visible to the unaided eye throughout most of May - with its brightest appearance around May 8. Comet LINEAR will join Comet NEAT in the western sky after sunset during the last week of May.
The comets should be visible above the western horizon after sunset and will look like fuzzy 'stars'. If you can get away from the influence of city lights, you should also be able to see the tails of the comets. Because a comet tail generally points away from the Sun, look for the tails to stretch upward in the sky. The darker the sky; the more you will be able to see.
You do NOT need a telescope to get the best view of a comet. The comet should be easily visible with just your eyes, especially from a dark, rural area. But whether observing from the city, suburbs, or Timbuktu, use binoculars to find the comet and follow the tail.
Don't let the media make you think the comet can only be seen on one particular night. It can be viewed in our evening sky from night to night for several weeks. The best viewing will be during the second week of May and over the Memorial Day weekend. If it should be cloudy for a few nights, don't give up. Just try again on the next clear night.
So Many Horses...?
This year has been unbelievably exciting for astronomy fans: landing, roving, and discoveries on Mars, lots of planets in the evening sky, the possibility of one, or two, naked eye comets in May, the Cassini spacecraft on final approach to Saturn, and so on.
To celebrate, we're bringing two teams of eight horses each to the Adventure Science Center for Astronomy Day.
Why? Because Nashville is a sister city to Magdeburg, Germany, whose most famous resident was Otto von Guericke. If the name doesn't sound familiar, von Guericke was the scientist who demonstrated the power of atmospheric pressure with a dramatic experiment in 1654. Von Guericke, inventor of the air pump, placed two metal hemispheres together to make a complete sphere twenty inches in diameter. When the air was pumped out, the external air pressure of the atmosphere kept them snugly sealed together. Even sixteen horses, eight on each side, could not pull the halves apart. It would've taken a force of over two tons to do it, but a twist of a valve was all that was needed to let the air back into the sphere so the hemispheres would fall apart with ease. Von Guericke thus proved that vacuums were possible and went on to speculate that the space between the stars was also a vacuum.
On Astronomy Day, April 24, 2004, the Adventure Science Center, the Otto von Guericke Society of Magdeburg, and Sister Cities of Nashville have arranged to reenact this famous experiment with actors from Germany in full costume and yes, real draft horses. This will be the first time such a performance has been done in the United States. It should be a very exciting day!
There will also be solar observing, video astronomy, telescopes, displays, exhibits, and a variety of other programs and activities presented by the Barnard-Seyfert Astronomical Society, the International Dark Sky Association, and other local organizations.
So Many Star Parties!
Don't forget, there's a star party on Friday, April 23 and several more in May! Check our star parties section for details!