Highland Road Park Observatory
Friday 5 July from 8:00 pm to 10:00 pm CDT
No admission fee. For all ages.
Binoculars strongly encouraged.
It’s not light, it’s not dark. It’s that special time called twilight, and HRPO wants to introduce you to it!
*Are all sections of the sky the same shade of blue?
*Which stars are seen first?
*Are Mercury☿ and Venus♀ or the Moon out?
*Is that moving object a plane, a satellite or space debris?
*How much actual darkness should I expect in a light-polluted city when twilight has passed?
There is no other time like twilight. Bring it into your life!
- 8:00 pm to 9:30 pm = Moon viewing
- 8:10 pm = “civil twilight” begins (search for crepuscular rays)
- 8:39 pm = “civil twilight” ends; “nautical twilight” begins
- 8:54 pm to 9:01 pm = magnitude 1.7 pass of the Hubble Space Telescope
- 9:12 pm = “nautical twilight” ends; “astronomical twilight” begins
- 9:15 pm to 9:24 pm = magnitude 1.8 pass of the Lacrosse 5 rocket
- 9:15 pm to 10:00 pm = Jupiter♃ viewing
- 9:45 pm to 10:00 pm = Saturn♄ viewing
- 9:47 pm = “astronomical twilight” ends
{The various twilights will be explained.}
Celestial Objects in Order of Appearance (with magnitudes):
Waxing Crescent Moon [-10.7] / Jupiter♃ [-2.5] / Arcturus [-0.05] / Vega [0.0] / Saturn♄ [0.1] / Mercury☿ [0.3] / Altair [0.7] / Aldebaran [0.8] / Spica [0.9] / Antares [1.0] / Regulus [1.3] / Polaris [2.0]
NOTE: The 26 July lecture “Wonders of the Summer Sky” is an excellent followup to this session.
This program pre-empts the Friday Night Lecture Series on…
*the last Friday in spring before Daylight Time begins
*the Friday during the week of Independence Day
*the first Friday in fall after Daylight Time ends
Updated by Frederick J. Barnett on Friday, June 21, 2019, 04:50 PM. | 
