Twin City Amateur Astronomers

Public Observing Sessions Cancelled!

In 2020, we have CANCELLED our public event in response to the COVID-19 pandemic.

We will post more information about online events as we learn more

From April through October, the TCAA holds monthly observing sessions that are open to the public. These "star parties" are held at our observatory at the Sugar Grove Nature Center, a dark sky site southwest of Bloomington.

Additional prominent sky objects such as planets, nebulae, star clusters, and galaxies will be viewed when visible.

DateFeatured TopicTime
April 25Mars & the Events of 202007:00PM - 09:00PM
Due to the COVID-19 pandemic, we are cancelling our in-person events for the season.Mars makes its closest approach to Earth every 780 days (1.9 years). The next closest approach will occur on October 13th, 2020 when it appears opposite the sun in the sky. Prepare now to observe Mars as it moves rapidly eastward among the stars of the zodiac, brightening all the while, and then suddenly executing an impressive 13-degree-long retrograde zigzag!
May 23Galaxies of the Spring08:45PM - 10:45PM
Due to the COVID-19 pandemic, we are cancelling out in-person event for the season. Stay tuned for information about our online events... In the spring, our line of sight on the sky looks straight out of our galaxy into the vast space beyond, showcasing thousands of bright galaxies and millions of dim ones. We will tour this neighborhood of the universe, highlighting some of the most beautiful galaxies in the heavens.
June 20Navigating with Stars09:00PM - 11:00PM
For centuries, navigators have relied on stars to identify directions, compute latitude, and even read local time. We will explore these ideas and also examine the problem of measuring one’s longitude at sea – a fascinating problem that defeated some of the best minds in the world for many years.
July 18Jupiter and Saturn09:00PM - 11:00PM
Jupiter and Saturn offer stark contrasts when compared to the inner planets. We will review how and why they formed in their current locations and their impact on the formation of the rest of the solar system. We will learn how the two greatest planets are similar yet different.
August 22Touring the Milky Way08:15PM - 10:15PM
The Milky Way is one of countless stellar islands floating in a cosmic foam of dark matter, dark energy, and matter. Humanity is trying to find out what our galaxy looks like inside and out using ingenious observing methods and increasingly more sensitive equipment. Take a tour of our “cosmic home” to see what we know so far.
September 19The ISS: Past, Present and Future07:30PM - 09:30PM
The International Space Station (ISS) is humankind’s largest artificial satellite. Given the right time and conditions, it can be easily seen orbiting overhead. We will look at how it was constructed, how it is used, what it is like living in space, and where it is headed in the future.
October 17Missions to Mars07:00PM - 09:00PM
As we reach our closest approach to Mars for the year, the Red Planet shines brightly throughout the evening. Let’s review the many spacecraft missions we’ve sent there, what they are revealing, and how they are paving the way for a future manned mission to Mars. In addition, we will have a laser-guided sky tour and telescope observing.

A Typical Public Viewing Session includes:
  • Lecture about the featured object.
    This 20-30 min. presentation, held in the SGNC picnic shelter, includes images of and details about the featured sky object as well as information on other interesting celestial objects that might be viewed that evening.
  • Sky tour using a laser pointer.
    We step out under the stars to point out the major constellations and planets, and to designate the location of the featured celestial object for the evening.
  • Telescope observing session.
    We use members' telescope at ground level to observe the featured object and other wonders of the heavens.

You can download our 2020 Public Viewing Session brochure.

If you would like to arrange a special event for your group, please follow this link to Request a Special Event.