Central Arkansas Astronomical Society Star Party, August 2018 John Reed

The Central Arkansas Astronomical Society, founded in 1971, cites part of its mission as “bringing the reality of the universe closer to the general public.” To do that, CAAS hosts monthly star parties at Pinnacle Mountain or Woolly Hollow State Park, operates the River Ridge Observatory near Lake Maumelle and generally educates visitors about how cool the sky is — and how light pollution can muck things up royally for stargazers and ecosystems everywhere.

So, as you’re spending your post-New Year days pondering ways to live the examined life, consider turning your gaze upward for a few nights (or early mornings) this year. Here are a few planetary and lunar phenomena to look for, courtesy of CAAS Outreach Coordinator Darrell Heath. And, thanks to a newly expanded telescope lending program at Central Arkansas Library System’s local branches, your eyes can get an assist when they need one; just ask your local librarian how to check out a telescope.


1. Jan. 20 marks a total lunar eclipse. It officially gets under way here in Arkansas at around 8:36 p.m., but don’t expect to see much until around 9:33 p.m. That’s when the moon will look like it’s had a bite taken out of it. Totality occurs at 10:41 p.m. and is at maximum by 11:12 p.m. During the 62 minutes leading up to totality, the moon will slowly change color from dark orange to a rusty red. This is because the light from the sun is getting filtered by the Earth’s atmosphere before it reaches the moon, and our atmosphere tends to absorb and scatter the bluer portions of sunlight while letting the red hues pass on through. By 11:43 p.m., totality is over and the moon starts to slowly move out from the Earth’s shadow.

2. On Jan. 22, get up early in the morning and face southeast to see a close pairing of Venus and Jupiter. Of course these kinds of pairings are a line of sight optical illusion, these two planets are not even remotely this close out in space, it just looks that way from here on Earth. We call these kinds of pairings “conjunctions.” On the morning of Jan. 31, look for a conjunction between Venus and Jupiter that now includes a crescent moon. These kinds of events don’t have any kind of significance to them, but they are darn pretty to look at.


3. The word “planet” comes from an Ancient Greek word that meant “wanderer.” In those days, no one could explain why certain bright stars moved around on the sky relative to all the other “fixed” stars. But those of us alive today can explain it: Those wanderers are not stars, they are other worlds just like the Earth. And, like us, they are orbiting around a central star, the Sun. But all the planets move around the Sun at different speeds. The inner planets move more quickly than do the outer planets. It’s this orbital motion around the Sun that makes them appear to wander relative to the stars. For example, around March 31, grab your binoculars, go outside and face west at 8 p.m., where you’ll see Mars just to the left of the lovely star cluster known as the Pleiades, or the “Seven Sisters.” A few nights later, on April 8, look again and you’ll see that the crescent moon has now joined the scene. The night sky is always changing due to the Earth rotating upon its axis and because the Earth, moon and planets are all, ultimately orbiting the Sun. This is one way you can see the results of all this motion from your own backyard.

4. On Nov. 11, if you have a telescope outfitted with solar safe filters, you can see the planet Mercury moving in between our line of sight to the Sun. The event is going on as the Sun rises, but Mercury does not creep into the Sun’s center until around 9:20 a.m. Look for an announcement from CAAS as the date approaches to see when and where we might have telescopes set up for viewing. Whenever Mercury or Venus moves in between our line of sight to the Sun, we call it a “transit,” and they are not very common. We won’t see Mercury do this again until the year 2032.


5. Closing out 2019, we will see another beautiful conjunction in our evening sky when the crescent moon pairs up with the “evening star,” the planet Venus. If you are a creative photographer, this would be a good opportunity to see if you can combine this celestial light show with that of some earthly, festive holiday lights.

To find out more about who CAAS is and what they do, go to caasastro.org.