*Special Astro-Events* at St Charles County Parks

In addition to the "Friday Night Open Houses", which are free and open to the public each and every clear Friday evening at Broemmelsiek Park, we have selectively scheduled some special dates this year with the St Charles County Parks department.   These are our "Special Events", and most are related to special astronomical events that we choose to support.  Note that meteor showers can be very negatively affected by a bright moon, so we selectively support them based on visibility and their Zenithal Hourly Rate.

All Public events feature several telescopes and operators who provide views thru their scopes free of charge.  Both members and non-members bring scopes.  Anyone who needs help with their own scopes are encouraged to bring them, however please have them available for us to help you with them before sundown.  If your scope is working fine, but you'd like help to find some objects, please just ask one of our members (most of which will have a name tag).  We are glad to help you find things with your scope, please ask!  It is a public park - you are welcome, please have fun and remember that we are volunteers.

General rules at star parties apply to help all of us retain our night vision.  Please avoid bringing flashlights (unless they are red or covered by red plastic, and kept pointed "downward") or any other lighted devices.  Try to avoid shining car headlights at the telescope field as you park or leave, else please minimize it as much as possible while remaining safe (use your parking lights).   
Again, we are at Broemmelsiek Park every Friday night if the weather allows. 

Here are the "Special Events" events being planned for 2020
 [ St Charles County Parks Info:     Phone: 636-949-7535 ( or email:   parks@sccmo.org) ]
[ ASEM Contact info:   Outreach@asemonline.org ]
                             or check our Facebook page


February 18 - 202o -   OCCULTATION OF MARS BY THE MOON (this event was clouded-out in StL)

      ASEM may or may not support this as an event at Broemmelsiek  Park from 5:45AM to 7:49AM, pending weather and attendees.

Just before sunrise, the moon will slowly pass over Mars!   Re-appearance won't be until after sunrise, so the main event will be the disappearance of Mars against the very bright edge of the lunar crescent.  Telescopes or binoculars are needed.

Occultation predictions of Mars         Magnitude 1.2
Date 2020 Feb 18

Moon: % illumination = 24-,  Solar elongation = 58

      Disappearance   (SUBTRACT 6 HRS FROM U.T. TO GET C.D.T.)
                                       U.T.  Sun Moon     CA  PA  WA   a    b
Location                             h  m  s Alt Alt Az    o   o   o  m/o  m/o
661 US St. Louis Mo                  11 59 18 -10 20 147 -83S  96  98 +1.7 +0.8

so:    5:59 AM

      Reappearance    (SUBTRACT 6 HRS FROM U.T. TO GET C.D.T.)
                                       U.T.  Sun Moon     CA  PA  WA   a    b
Location                             h  m  s Alt Alt Az    o   o   o  m/o  m/o
661 US St. Louis Mo                  13 29 52   7 27 168  71N 287 290 +2.2 -0.1

so:   7:29 AM


The Perseid Meteor Shower (Aug 12/13)=Weds eve/Thurs AM

*** This event is hereby CANCELLED due to Covid-19 & the inability to have Social Distancing or mask-wearing. ***

—Not yet an "official" St Charles County Parks event.  Join us at Broemmelsiek Park.    Fortunately, this year the moon is just past Last Quarter (Waning Crescent).  This will be a much better event than with a full moon in 2019, if the sky is clear.  *ALL EVENTS ARE DEPENDENT ON THE WEATHER*  Best viewing this year is from 10PM thru 12:30 AM.  Moonrise is 11:53 AM on August 12.
              (Dates shown may be affected by local weather.  We may locally choose the night before or after if necessary.)

Per the American Meteor Society:
The Perseids are the most popular meteor shower as they peak on warm August nights as seen from the northern hemisphere. The Perseids are active from July 13 to August 26. They reach a strong maximum on August 12 or 13, depending on the year. Normal rates seen from rural locations range from 50-75 shower members per hour at maximum.The Perseids are particles released from comet 109P/Swift-Tuttle during its numerous returns to the inner solar system. They are called Perseids since the radiant (the area of the sky where the meteors seem to originate) is located near the prominent constellation of Perseus the hero when at maximum activity.



While Mars reaches opposition with the Earth on October 13, it will be nearly as close and will be best enjoyed by public telescope viewers from roughly October 1st thru November. So we will not have a specific event on October 13.  We will be "featuring" Mars at our weekly FRIDAY NIGHT OPEN HOUSES throughout the months of October and November.

Our digital-SIG astrophotographers will be obtaining Mars 'data' from about 1-2 months prior to opposition until about 1 month after.

Mars oppositions only come once every two years.  This is our best opportunity to view Mars until very late in 2022.

Closest approach occurs at 1419 UT on October 06, 2020 (291.0° Ls) with an apparent planetary disk diameter of 22.6’’ at a distance of 0.414909454147 astronomical units (AU) or 38,568,243 mi (62,069,571-km).   During closest approach in 2020 the apparent diameter of Mars will be 1.7 arc sec smaller than it was at the same period in 2018; however, it will be 31 degrees higher in the sky – good for observing the Red Planet for observers in the northern and southern hemispheres of Earth.  It should also be noted that closest approach between Earth and Mars is not necessarily coincident with the time of opposition but varies by as much as two weeks.



Not yet an "official" St Charles County event.  It is likely to be cancelled due to Covid-19, if need be.

In 2020, the peak of the Geminids coincides with a New Moon, so conditions are ideal. It is one of the most active showers of the year, and in some years is the strongest, with a peak rate of around 100 meteors per hour. It is the one major shower that shows good activity before midnight (the constellation of Gemini is well placed from 10:00PM onward).

Hunting for meteors, like the rest of astronomy, is a waiting game, so it's best to bring a comfy chair to sit on and to wrap up warm as you could be outside for a while. They can be seen with the naked eye so there's no need for binoculars or a telescope, though you will need to allow your eyes to adjust to the dark.

It is best not to look directly at the radiant as this can limit the number of meteors you see. Try instead to look just to the side in a dark area of sky and you will be more likely to catch sight of some meteors with long trails!

Geminid facts

  • Together with the Quadrantids, the Geminids are the only major meteor showers not originating from a comet.
  • The beautiful streaks we see in the night sky can actually be caused by particles as small as a grain of sand!
  • Geminids were first observed in 1862, much more recently than other showers such as the Perseids and Leonids.
  • The Geminids are thought to be intensifying every year.


SUNDAY December 20, 2020  - Solstice HYPER-CONJUNCTION of JUPITER and SATURN  -  5:15PM - 6:20 PM

Description:  Saturn seen as close to Jupiter as some of Jupiter’s moons thru a telescope.  Both will be very low in the Southwest after sunset (4:46 PM).   During this time, Jupiter and Saturn will only be around 18* high at first viewing, so the images won't be great, just cool to see them this close together.  They may be a more beautiful sight naked-eye or through binoculars than with  much magnification thru a telescope.

We anticipate both "astrologers" and the media to promote this special event.  "Great" conjunctions of Jupiter and Saturn occur roughly every 20 years.  This one is extra-special due to the very close proximity at the time of conjunction.