JOHNSON CITY – East Tennessee State University's Harry Powell Observatory will be open tonight from 7-9 p.m., if weather permits, for observation of the lunar occultation of Saturn.
The moon will pass in front of the planet Saturn and remain in front of it for about an hour. Such an astronomical event, when one object passes through the line of sight of another, is called an occultation, according to ETSU astronomer Dr. Harry Powell. This occultation of Saturn by the moon will begin at about 7:30 p.m. and last for approximately an hour for observers in East Tennessee.
"The full moon will rise in the eastern sky just about sunset," Powell said. "At that time, Saturn will be a bright object just to the east of the moon. During the next hour or so, the moon and Saturn will rise above the horizon and the separation between them will steadily decrease as the moon moves eastward relative to the background of stars and planets. At about 7:30, give or take maybe 10 minutes, the eastern limb of the moon will begin its sweep across Saturn. Saturn will remain occulted by the moon for about an hour, when it will reappear on the moon's western limb."
Powell added that a telescope is not necessary to observe this "exciting astronomical phenomenon."
"Given sufficiently clear skies, you should have no problem discerning Saturn just to the left of the moon low in the east at 7 p.m., or the disappearance of Saturn as the moon moves across it about 7:30," he said. "A telescopic view will simply add to the details. Since Saturn is seen as an extended body, its disappearance, viewed through a telescope, will take place gradually over several seconds as the limb of the moon moves across the planet from right to left."
If skies are clear and the observatory is open, ETSU faculty and students will use Meade LX-200 computer-controlled telescopes to help visitors view the occultation. They will also project the image from the main telescope onto the observatory's big-screen TV.
The ETSU Powell Astronomy Observatory is located just off College Heights and Narrow Lane above the ETSU campus. Maps are available online at http://www.etsu.edu/physics/etsuobs/jcmap.htm.
For more information or for special assistance for persons with disabilities, call Powell at (423) 439-6904 or Dr. Beverly Smith, assistant professor of physics and astronomy, at 439-8418.