"For those who are awake the cosmos is one."

– Heraclitus

CAA Public Events 2019

Young Observer at C16

A young observer peers through the CAA's vintage Celestron 16 telescope.


The CAA hosts at least 12 Saturday Public Observing events featuring a guest speaker that is followed—weather permitting—by celestial viewings through telescopes at the facility. During viewing hours, society members will be available to answer questions and provide everyone with an opportunity to look through the Society's telescopes and those of our members.

This site will be updated through out the year as we assemble our speakers and events.

 Future Presentations

January 29th 2022, 7:30 PM - Virtual Event Only

 Title: TBD

Presenter: Professor Evan Skillman



February 26th 2022, 7:30 PM - Virtual Event Only

 Title: TBD

Presenter: Professor Clement Pryke


March 26th 2022, 7:30 PM

 Title: Open Star Clusters: Jewels of the Spring Sky

Presenter: Professor Steven Spangler

Synopsis: Open star clusters are some of the favorite objects of amateur astronomers, and this time of year (March- April) is about the best time to see them. We can see some open clusters with the naked eye, and many more are visible with a pair of binoculars. Telescopes show them for what they are, collections of hundreds or thousands of stars moving together through space. Although we have known their basic properties for many decades, recent results from the GAIA spacecraft and large ground-based telescopes have provided major advances. In this talk, I will describe how to find them in the night sky, basically what they are, and what new we have learned in the last 5 to 10 years.



April 23rd 2022, 8:00 PM

 Title: TBD

Presenter: TBD



May 7th 2022, 8:00 PM

 Title: What scientists can learn from studying meteorites and their impacts

Presenter: Professor David Peate

Synopsis: Sending spacecraft to planetary bodies is an expensive way to collect samples, but nature does this for us for free thanks to the regular delivery of meteorites 'falling from the sky'. In this talk, I will discuss how the study of meteorites can reveal details of the early history of our Solar System and how planets formed, and how we know where in the Solar System most meteorites come from. I will also talk about scientists finding unusual materials in some meteorites like organic molecules as well as grains that are older than the Solar System. I will finish by describing some of my own reseach on the Monturaqui impact crater in Chile that was formed by the impact of a ~15 m diameter iron meteorite, creating a 450 m diameter crater, and melt ejecta containing droplets of metal.

Bio: David W Peate is a Professor of Geochemistry at the University of Iowa, and currently Chair of the Department of Earth & Environmental Sciences.His research focus is understanding how the Earth's mantle melts and how magmas rise through the Earth's crust to form volcanoes, through detailed study of the chemical composition of volcanic rocks and minerals. He has had a life-long fascination with planetary geology inspired by watching the Apollo 11 moon landings as a small child in the UK, which has led to side projects looking at impact craters and meteorites.







May 21st 2022, 8:30 PM

 Title: TBD

Presenter: TBD



June 18th 2022, 8:30 PM

 Title: TBD

Presenter: TBD



July 9th 2022, 3:00 - 6:00 PM - Solar Saturday

 Title: TBD

Presenter: Mr. Carl Bracken



July 23rd 2022, 8:30 PM

 Title: TBD

Presenter: TBD



August 20th 2022, 8:00 PM

 Title: TBD

Presenter:Professor Brent Studer



September 17th 2022, 7:30 PM

 Title: TBD

Presenter: TBD


October 1st 2022,7:30 PM - InOMN - International Observe the Moon Night

 Title: TBD

Presenter: Mr. Doug Slauson


October 15th 2022, 7:30 PM

 Title: TBD

Presenter: TBD


November 19th 7:30 PM

 Title: TBD

Presenter: TBD


December 10th 7:30 PM - Virtual Event Only

 Title: TBD

Presenter: TBD


2021 Past Presentations

January 16, 7:30 p.m.

Nancy Atkinson, contributing editor for Universe Today- www.universetoday.com

Eight Years to the Moon: The History of the Apollo Missions

"The stories of 45 engineers and scientists who worked behind the scenes to make it possible to land on the Moon. Many of these people have gone unheralded for their work, but their contributions were vital to meeting the challenges of such an audacious project. These are stories from the 1960's that you won't find anywhere else."

February 13, 7:30 p.m.

Charles (Chuck) E. Allen, Vice President, Astronomical League

Cosmic Horizons

Cosmic Horizons explores the limits of human visibility imposed by planetary curvature, photon sensitivity of the human eye, and the speed of light in an expanding universe. We briefly explore the definition of planetary horizons and the role of planetary size in defining them. Next, we examine the faintest astronomical objects we can see with and without optical aid, and the smallest number of photons theoretically detectable by humans. Finally, we discuss the four horizons imposed by time and the speed of light (the Hubble distance, cosmic particle horizon, cosmic event horizon, and future visibility horizon) and consider how these horizons change in an accelerating universe and what effect they have on what we can, or ever will, see.

Chuck Allen

Chuck is currently Vice-President, and also past-President, of the Astronomical League. He founded the League’s 30 year-old National Young Astronomer Award in 1991, received the G. R. Wright Award for service in 1998, and holds the League’s Master Outreach Award with more than 500 public programs to his credit. He is a League Master Observer with 38 programs completed, three of which he coordinates.

Chuck is Program Director for the Evansville Astronomical Society and past President of the Louisville Astronomical Society (1991-94). From 1995 to 2002, he served as Judge, and once as Lead Judge, in earth and space science for the Intel International Science and Engineering Fair. Chuck graduated from Duke University in 1970, served as a U.S. Air Force officer from 1970 to 1974, and graduated from the University of Kentucky College of Law in 1977. He was a partner with Kentucky's largest law firm, Frost, Brown Todd LLC, where he practiced for 27 years.


March 6, 7:30 p.m.

Tom Field, Field Tested Systems

You can almost touch the stars

Even if you wanted to touch a star, they’re all impossibly distant. Despite these great distances, astronomers have learned an enormous amount about stars. How? The most common method to study the stars is called spectroscopy, which is the science of analyzing the colorful rainbow spectrum produced by a prism-like device. Until recently, spectroscopy was too expensive and too complicated for all but a handful of amateurs. Today, though, new tools make spectroscopy accessible to almost all of us. You no longer need a PhD, dark skies, long exposures, enormous aperture … or a big budget! With your current telescope and FITS camera (or a simple web cam or even a DSLR without a telescope) you can now easily study the stars yourself. Wouldn’t you like to detect the atmosphere on Neptune or the red shift of a quasar right from your own backyard?! This talk, with lots of interesting examples, will show you what it’s all about and help you understand how spectroscopy is used in research. Even if you are an armchair astronomer, understanding this field will enhance your understanding of the things you read and the night sky.

Tom Field

Tom Field has been a Contributing Editor at Sky & Telescope Magazine for the past 7 years. He is the author of  the RSpec software (www.rspec-astro.com) which received the S&T “Hot Product” award in 2011. Tom is a popular speaker who has spoken to hundreds of clubs via the web and in-person at many conferences, including NEAF, the NEAF Imaging Conference, the Winter Star Party, the Advanced Imaging Conference, and other


April 3, 7:30 p.m.
Professor Steven Spangler, University of Iowa Physics and Astronomy
O Type Stars in the Night Sky

We learn in school that stars are like the Sun, only very far away.  Or, the Sun is a star which is very close to us.  How similar are the stars in the night sky to our Sun?  A short answer would be that they are similar in kind, but quite different in degree.  They range enormously in mass (amount of matter in them), brightness, and temperature at their surfaces.  The most massive, brightest, and hottest stars are called the O stars.  The term “O star” is a holdover from early astronomical research, but the category contains a set of stars with extravagant properties.  In particular, they are much hotter and much brighter beacons than our Sun.  In spite of this, none of the 26 brightest stars in the sky is an O star.  In this talk, I will explain why this is true, and where you can find stars in the night sky that are these remarkable objects. 

Topic: O Stars in the Night Sky
Time: Apr 3, 2021 07:30 PM Central Time (US and Canada)

May 1, 8:00 p.m.


Dr. Sadie Elliott, Postdoctoral Research Scholar

University of Iowa Department of Physics and Astronomy

New discoveries made by the Juno mission to Jupiter

NASA’s Juno mission to Jupiter was launched in 2011. Since its arrival at Jupiter on July 4, 2016, Juno has made a number of scientific discoveries. Juno is the first spacecraft to make in-situ measurements of Jupiter’s polar magnetosphere and aurora. Some surprising high-latitude discoveries include observations of highly energetic electron beams, intense broadband plasma waves, and elevated electron densities due to the presence of the Io plasma torus. In this talk, I will present an overview of the Juno mission and the University of Iowa’s involvement. I will also present scientific results from Juno’s prime mission, specifically observations made by Juno’s radio and plasma wave instrument.


May 15, 2021

8:30 p.m.

Rachael Filwett , Ph.D.

Title: Solar energetic particles and their influence on modern society


In our technologically-driven society we have become increasingly reliant on stable power supplies. Similar to terrestrial based weather sources that can be devastating to a region, such as the derecho last year, outer space can produce a variety of weather hazards. I’ll discuss how these hazards vary by terrestrial location, and how they come in ‘seasons’. The number of spacecraft is increasing rapidly, and NASA has plans to return astronauts to the moon and then on to Mars, adding urgency to mitigate space weather risks.  I’ll talk about what space weather is, what we can do about it, and how my personal research plays a small role in this important task.

Virtual Meeting Information:

Topic: Space Weather for a Modern Society
Time: May 15, 2021 08:30 PM Central Time (US and Canada)


June 12, 8:30 p.m.

Presenter: Dr. Charles Kerton- Associate professor of astronomy 

The Department of Physics & Astronomy at Iowa State University

Title: Adventures in Citizen Science or Astronomy for Cloudy Nights

This talk will describe work done by astronomers based at Iowa State University and the Adler Planetarium to understand the nature of thousands of compact, infrared sources identified by the over 50,000 citizen scientists participating in the Milky Way Project. Most of these objects represent an early stage in the evolution of massive stars.Trying to understand why many of these objects were not identified in previous Galactic infrared surveys leads to some interesting insights into how the mid-infrared emission from a massive star-forming region changes as it evolves. I will also briefly describe some of the other active citizenscience projects related to astronomy.

Bio: Dr. Charles Kerton is an associate professor of astronomy in the Department of Physics & Astronomy at Iowa State University. His research focus is on observational studies of high-mass star formation and the effect of massive stars on the interstellar medium using infrared and radio data. At Iowa State he also enjoys teaching classes ranging from undergraduate survey courses to specialized graduate seminars. Even though astronomy is his job, he still likes to look at the night sky from time to time just for fun!



July 10, 8:30 p.m.

Presenter: John Leeson, Cedar Amateur Astronomers Vice President

Title: Observing the Sky for Beginners

If you are somewhat new to trying to observe the night sky with your new telescope or binoculars, or just starting to think about observing the night sky, then maybe we can help get you started. One of the first things beginners want to know is what can I see and how do I find it? That is what we hope to answer here tonight. There is always something to look for whether you are using just your eyes, binoculars, or your amateur class telescope and there are lots of tools to help you figure it out. We will be using printed Sky Maps and Stellarium planetarium software primarily. There is no cost for these tools, the software is open source and free to use and the sky maps can be downloaded and printed for free. With these you can plan your observing night activities ahead of time and also know what you can expect to see, so you will know how to tell if you are successful.



July 31, 8:30 p.m.

 Presenter: David Falkner

Title: The Mythology of the Night Sky
"Most of the constellations we see from the northern hemisphere have their roots in Greek and Roman mythology. Dave will talk about the history leading up to the naming of the constellations, some of the stories found in the constellations, and how they relate to life in ancient Greece and Rome.

Dave will also talk about the tradition of naming solar system objects based on Greco-Roman mythological characters, one significant deviation from that, and how in more recent times the naming convention has expanded to other mythologies."


Dave Falkner has been a life-long amateur astronomer. He first became interested in Astronomy as a pre-teen when his father took him to a show at the Holcolm Planetarium in Indianapolis.  He became hooked and has had an interest in astronomy ever since.  As a teenager he ground a 6” mirror and built his first telescope.  As a Naval Officer stationed in Monterey, California he was involved with the Friends of MIRA (Monterey Institute for Research in Astronomy) where he conducted outreach to local schools associated with the return of Halley’s Comet.

After a successful 20-year career Dave retired from the US Navy and settled in Minnesota where he became an active member of the Minnesota Astronomical Society. He has served as its President and enjoys performing astronomical outreach often speaking to groups at libraries, nature centers and schools. He is a NASA/JPL Solar System Ambassador and has authored the book “The Mythology of the Night Sky – Greek, Roman and Other Celestial Lore, Second Edition.”



August 14, 12 noon and 3:00 p.m. – 6:00 p.m.

 This event will be held in person as well as Zoom

Presenter: CAA Treasurer Mr. Carl Bracken

Title: Our Sun and Solar Activity Cycles

The presentation will be at noon, then the recorded program will be played back at 3pm. Solar observing using the association's solar-filter equipped telescope will follow the presentation and again following the 3pm playback. CAA members will be on-site to give tours of the observatory, assist with telescopes and answer questions. Only specially equipped optical aids can be used to observe the sun without endangering eye damage. CAA has four optical telescopes with solar filters and two sun projection viewers, plus some of the members will bring thier own telescopes with solar filters.

Synopsis:The sun completes one full magnetic field cycle every 22 years on average. The familiar cycle of sunspot minimum to sunspot maximum back to minimum lasts on average 11 years; two full sunspot cycles are part of each solar magnetic field cycle. The Wilcox solar Observatory or WSO near the campus of Stanford University in Northern California has produced daily solar polar field measurements since May 1976 forming a unique dataset of key solar characteristics unmatched anywhere in the world. In this presentation we will look at the WSO dataset to illustrate the dynamic nature of the solar magnetic field.

The geologic record shows us that Earth's magnetic dipole field also shifts over long time frames. Like the sun the geomagnetic field surrounding our planet is complex and has different cycles on vastly different time horizons. The more familiar magnetic pole reversal is thought to have last occurred approximately 780,000 years ago. The geologic record also points to another magnetic pole shift event that occurs on a time horizon of approximately 12,000 – 13,000 years known as a geomagnetic excursion. Unlike the full pole reversal, the excursion event does not permanently change the orientation of the dipole. However, it does introduce a significant reduction in field strength and temporarily changes pole orientation. The duration of the excursion event is thought to last a few thousand years with the poles eventually returning to their original orientation. The geomagnetic field is important for everyday activities such as navigation, and protection from high energy radiation from our sun as well as our own galaxy, and even deep space beyond our Milky Way.

In this presentation we will look at how the dynamic solar magnetic field and the geomagnetic field interact and some of the impacts from the interaction. We will also look at some interesting cold war era history of discovery by the US military studying the impacts on navigation over the geomagnetic North pole during long range bombing missions.



August 28, 8:00 p.m.

This event will be held in person as well as Zoom

Presenter: Riley Troyer, graduate student, University of Iowa Department of Physics and Astronomy

Title: Northern Lights in Iowa: a discussion about the aurora, their science, common misconceptions, and the possibility of seeing them here

Bio: I was born and raised in Fairbanks, Alaska. I’ve always been interested in science, but in high school I discovered astronomy and was hooked. This led me to pursue a degree in physics from the University of Alaska Fairbanks. While studying physics, I started researching the aurora (northern lights). Living in Alaska, I’ve seen the aurora many times, but understanding how it is formed gave me an entirely new perspective. Once again, I was hooked. Funny enough, I decided to move south to continue this interest as a space physics graduate student at the University of Iowa. I am now in my 4th year as a Ph.D. candidate studying a specific type of northern lights known as pulsating aurora. Outside of research, I have an interest in science policy and helped found the UI science policy and communication student organization (Connecting Science to Society). I am also an avid cyclist and cross-country skier and enjoy a variety of other outdoor activities. However, I’m only now getting used to the hot and humid Midwest summers.  

Synopsis: The aurora, also known as the northern/southern lights, are a majestic and awe-inspiring display of nature that occurs in the far north and south. These green, red, and sometimes even blue curtains of light have been marveled over for as long as humanity has existed in such places. However, our scientific understanding of them is not nearly as old and there is still much we don’t understand. In this talk, I will describe how the aurora are formed and address some widespread misconceptions. Since the sun is becoming more active, which leads to stronger aurora, I will also discuss how to tell when we might catch a glimpse of them here in Iowa and if so, how to best take advantage of that. I’ll also describe my own research area, a fascinating type of northern lights called pulsating aurora and how they differ from “normal” aurora. Finally, I’ll touch on why it is important that we study these lights and the impacts they can have on society.



September 25, 7:30 p.m.

This event will be held in person as well as Zoom

Zachary Luppen – PhD Student of Aerospace Engineering, Department of Aerospace Engineering at Iowa State University

Developing Reusable Rockets to Reach the Moon and Mars: What It’s Like to Work for SpaceX


Space Exploration Technologies Corporation (SpaceX) was founded in 2002 by Elon Musk with the goal of reducing costs to space access and to enable the colonization of Mars. After launching the first privately funded liquid-propellant rocket to reach orbit in 2008, the company has made leaps in bounds in space exploration technology. Applying a vertical integration structure and working towards rocket reuse from the beginning, the company has provided much easier and cheaper access to space. In Spring 2020, the company’s work culminated in the launch of Crew Dragon Demo-2, the first private launch of astronauts to orbit and the International Space Station (ISS).

During Summer 2021, I was invited to intern at SpaceX as part of the core avionics engineering group. My work involved rigorous testing of electrical, electronic, and electromechanical (EEE) components to ensure reusability on multiple missions. In this talk, I will discuss the mission and projects of SpaceX, describe the work I performed (to the extent that I am allowed), and tell you about the company’s fast-track plan to put humans on Mars.


Zachary Luppen is a PhD student of aerospace engineering at Iowa State University. Originally from Omaha, Nebraska, he attended the University of Iowa from 2015-2018, earning degrees in astronomy and physics, with honors. During that time, he participated in a handful of events with the Cedar Amateur Astronomers, including giving past talks at the observatory. At Iowa State, he is currently studying formal methodologies used to specify, verify, and validate space systems. He is expecting to achieve his MS in Fall 2021 and his PhD in Spring 2024. In his free time, Zachary enjoys flying as a private pilot, skydiving, reading, biking, and running.




 October 16, 7:30 p.m.

This event will be held in person as well as Zoom

Presenter: Dr. Jasper Halekas

University of Iowa, Department of Physics and Astronomy

 Title: Earth’s Moon: International Observe the Moon Night

The Moon, our nearest neighbor and closest companion, is a constant presence in the sky and in our culture. I will discuss the history of lunar exploration, what we have learned about the Moon through this exploration, and some of the many things we still don't know about the Moon. I'll end with a look to the future, describing a new mission to the Moon that will launch in a few years, with involvement from the University of Iowa. 

Jasper Halekas is an Associate Professor in the Department of Physics and Astronomy at the University of Iowa. Prof. Halekas's research focuses on the impact of the Sun and the solar wind on our solar system and its evolution. He designs and builds spaceflight instruments to measure charged particles, and uses these measurements to explore the interplanetary medium and the environments near the various bodies of our solar system.




October 30, 7:30 p.m.


Astronomy Professor Larry Molnar believes he can find the unfindable – a star that is about to explode!

When Larry and a small team of students stumble across a strange star, they embark on a dramatic journey of scientific discovery, which brings the unlikely team into the international spotlight. But others in the astronomical community are skeptical, and Larry’s professional reputation hangs in the balance. In production since 2014, Luminous, a feature documentary by award-winning filmmaker Sam Smartt (Wagonmasters), follows Larry’s journey to test his unprecedented prediction, knowing that its success or failure will unfold squarely in the international spotlight.




 November 27, 7:30 p.m.

Presenter: Dr. Steven Spangler, Emeritus Professor, Department of Physics and Astronomy, The University of Iowa

Title: A Bubble in Space

 We usually think of the space between the stars as being completely empty.  However, this space is filled with very dilute matter that astronomers call the interstellar medium.  Research has shown that the Sun is located within an unusual hole in the interstellar medium called the Local Bubble or Local Cavity.  There has to be some matter in the Local Bubble, but scientists still disagree on its pressure and temperature.  I will describe the observations that show this bubble exists, discuss how it was formed and is maintained in its present condition, and what it implies for other aspects of astronomy.  



 December 18th 2021, 7:30 PM - Canceled




Public observing events are held in the Eastern Iowa Observatory and Learning Center at the Palisades-Dows Observatory and Preserve through a generous agreement with the Linn County Conservation Department. For directions, please visit our Map to Pal-Dows page or download a pdf version (276 kB.)

The Cedar Amateur Astronomers, Inc. is a participating member of Night Sky Network.