Happening at the Crossroads
April 16, 2007
Earth Day is a special day at Crossroads, but this year, it will be a special day for those who are interested in space as well. The hours right before dawn Sunday morning should be the peak of the Lyrid meteor shower.
Meteor showers happen at a "crossroads" in space. The Earth travels around, or orbits, the Sun once a year. Comets also travel around the sun in orbits. One such comet, Comet Thatcher, orbits the Sun every 415 years. Its last pass was in 1861. As it went around the sun, the comet's dusty tail left a bit of cosmic litter. Most of this comet debris is tiny... rock particles no bigger than grains of sand. When the orbital path of the Earth intersects the orbital path of a comet, these small rocks strike the Earth's atmosphere.
In the Door Peninsula Astronomical Society newsletter the Blue Moon Observer, DPAS President, Dr. John Beck explains," The particles from the comet trail... strike the atmosphere at about 71 kilometers/second. The collision with atmospheric molecules strips the outer layers of the particle, creating vapors of various metals. Subsequent collisions raise the electrons to higher orbits around their nuclei. When the electrons return to their original orbits, light is produced. The color of the light depends upon the metal. For example, sodium gives off a yellow and is often the source of most of the light seen when a meteor steaks across the sky."
On Saturday afternoon at 3:00, a Family Program called "What is a Meteor?" will be presented in the Collins Learning Center. This multi-media presentation is appropriate for elementary-aged students, but learners of all ages are welcome to join in the interactive program.
The ever-optimistic members of the Door Peninsula Astronomical Society have planned a viewing night beginning at 8:00 PM on Saturday, April 21 in the StarGarden of the Leif Everson Observatory (turn left into Crossroads at the first stop sign past Highway 42/57 on Utah Street.) The standing water which prevented the March viewing night is gone and the road is now passable.
Participants will be invited to view the night skies through a variety of telescopes. Who knows? Sky watchers may just see a meteor or two early in the evening. And if the sky is cloudy, a program on telescopes will be presented in the Stonecipher Astronomy Center near the observatory.
Crossroads at Big Creek is donor supported learning preserve dedicated to experience-based learning in science, history and the environment. The Collins Learning Center is located on County TT (Michigan Street) and the astronomy campus can be reached by turning into Crossroads at the first stop sign after the highway on Utah Street. For more information, call 746-5895.
