Check out the link above for our 2018 Outreach Schedule. Always a work in progress, check often.

About Us

The Grand Traverse Astronomical Society is a nonprofit organization dedicated to to education and enjoyment of the night sky. Established in 1982, the GTAS has about 30 members from the Traverse City and the Grand Traverse area of northern Michigan.  Meetings are held on the first Friday of every month beginning at 8 p.m. at Northwestern Michigan College's Joseph H. Rogers Observatory, though the August meeting is preempted by the annual picnic at another location.

Guests are always welcome to our meetings.

Over 750 attended the society sponsored Comet Hyakutake Watches March 23, and 24th, 1996. The farthest traveler came from Detroit to enjoy the dark skies and the spectacular comet through many telescopes. Comet Hale-Bopp attracted approximately 1,400 during the three scheduled viewing nights that were clear.

We've hit the road, so to speak, with outreach beyond the NMC Observatory since 2007. Since 2011 we've held monthly star parties at Sleeping Bear Dunes National Lakeshore from April to October with additional eclipse and meteor shower watches. We bring our telescopes and exhibits to several festivals around the area along with Friday Night Live in Traverse City. Since 2010 the society has been hosting monthly star parties at the Sleeping Bear Dunes National Lakeshore, and beginning in 2016 at the Arcadia Dunes.

The GTAS belongs to the International Dark-Sky Association and participates in Project Astro.

We also participate in the annual International Observe the Moon Night.

Upcoming Meetings and Outreach Events

Note that outdoor events are weather permitting

April 6th, Friday

GTAS Monthly Meeting: 8 p.m. - NMC Rogers Observatory.

Program: Professor Jerry Dobek: Protecting our dark skies

Star Party: 9 p.m. - NMC Rogers Observatory.
If it's clear: Venus early, Great Orion Nebula later.

April 14th, Saturday

Star Party: 9 p.m. - Sleeping Bear Dunes National Lakeshore, Platte River Point. Venus til after 10, Orion Nebula after 9:30 (twilight).

April 21st, Saturday

Astronomy Day Star Party: 9 p.m. - NMC Rogers Observatory.
If it's clear: Venus early, Moon, Jupiter late from dome.

May 4th, Friday

GTAS Monthly Meeting: 8 p.m. - NMC Rogers Observatory.

Program: Bob Moler- Topic: The importance of Venus to the ancients

Star Party: 9 p.m. - NMC Rogers Observatory.
If it's clear: Venus, Moon, Jupiter after 10 p.m.

This article is provided by NASA Space Place.

With articles, activities, crafts, games, and lesson plans, NASA Space Place encourages everyone to get excited about science and technology. Visit to explore space and Earth science!

Measuring the Movement of Water on Earth

By Teagan Wall

As far as we know, water is essential for every form of life. It’s a simple molecule, and we know a lot about it. Water has two hydrogen atoms and one oxygen atom. It boils at 212° Fahrenheit (100° Celsius) and freezes at 32° Fahrenheit (0° Celsius). The Earth’s surface is more than 70 percent covered in water.

On our planet, we find water at every stage: liquid, solid (ice), and gas (steam and vapor). Our bodies are mostly water. We use it to drink, bathe, clean, grow crops, make energy, and more. With everything it does, measuring where the water on Earth is, and how it moves, is no easy task.

The world’s oceans, lakes, rivers and streams are water. However, there’s also water frozen in the ice caps, glaciers, and icebergs. There’s water held in the tiny spaces between rocks and soils deep underground. With so much water all over the planet—including some of it hidden where we can’t see—NASA scientists have to get creative to study it all. One way that NASA will measure where all that water is and how it moves, is by launching a set of spacecraft this spring called GRACE-FO.

GRACE-FO stands for the “Gravity Recovery and Climate Experiment Follow-on.” “Follow-on” means it’s the second satellite mission like this—a follow-up to the original GRACE mission. GRACE-FO will use two satellites. One satellite will be about 137 miles (220 km) behind the other as they orbit the Earth. As the satellites move, the gravity of the Earth will pull on them.

Gravity isn’t the same everywhere on Earth. Areas with more mass—like big mountains—have a stronger gravitational pull than areas with less mass. When the GRACE-FO satellites fly towards an area with stronger gravitational pull, the first satellite will be pulled a little faster. When the second GRACE-FO satellite reaches the stronger gravity area, it will be pulled faster, and catch up. 

Scientists combine this distance between the two satellites with lots of other information to create a map of Earth’s gravity field each month. The changes in that map will tell them how land and water move on our planet. For example, a melting glacier will have less water, and so less mass, as it melts. Less mass means less gravitational pull, so the GRACE-FO satellites will have less distance between them. That data can be used to help scientists figure out if the glacier is melting.

GRACE-FO will also be able to look at how Earth’s overall weather changes from year to year. For example, the satellite can monitor certain regions to help us figure out how severe a drought is. These satellites will help us keep track of one of the most important things to all life on this planet: water.

You can learn more about our planet’s most important molecule here:

An artist's rendering of the twin GRACE-FO spacecraft in orbit around Earth. Credit: NASA

NASA Space Place poster

Download the poster by clicking the image above.

To see the video that goes along with this poster, visit:


For Kids: NASA’s Space Place website

The Space Place is a NASA website for elementary school-aged kids, their teachers, and their parents.

It’s colorful!
It’s dynamic!
It’s fun!

It’s rich with science, technology, engineering, and math content!

It’s informal. It’s meaty. It’s easy to read and understand. It’s also in Spanish. And it’s free!

It has over 150 separate modules for kids, including hands-on projects, interactive games, animated cartoons, and amazing facts about space and Earth science and technology.

See this month's Space Place article at the bottom of the center panel on this page.

Also check out these two sites for kids: NASA's Climate Kids and NOAA's SciJinks

Bob Moler's Ephemeris contains audio mp3s of current Ephemeris programs; calendars of sunrise, sunset,moonrise and moonset for the Grand Traverse area of Michigan, and other locations in northern Michigan; plus a monthly star chart.

Also  Bob's Ephemeris Blog with daily transcripts of and illustrations for his daily Ephemeris programs on Interlochen Public Radio.

Northwestern Michigan College's Joseph H. Rogers Observatory

If you'd like to donate

From Article II, B of the Articles of Incorporation of the Grand Traverse Astronomical Society:

The Society shall operate a scientific and educational organization with the goal of increasing interest in, the knowledge and enjoyment of astronomy; cooperate with similar organizations; and cooperate with Northwestern Michigan College to increase the benefit of the college observatory to the community.

As you can see by the statement above the society is inexorably linked to the Joseph H. Rogers observatory.  However in the past number of years members have been also taking telescopes out into the community, on sidewalks and street corners, and in the street on Friday Night Live, and to the Sleeping Bear Dunes National Lakeshore. We find that many folks in the area have never been out to the observatory. This way we are going to to the public. And having a huge telescope is really be a huge attraction, not to mention the superb views of the heavens it will provide.

We have purchased a 25 inch Dobsonian telescope with trailer to use and to take around for our outreach program. We have also purchased a solar telescope to view the Sun's prominences, and are looking to obtain a second solar telescope. We feature a solar viewing time at the Sleeping Bear Dunes before the star parties in June, July and August.

We have recently purchased small telescopes to give to libraries for them to lend out. The first two recipients are Traverse Area District Library and Betsie Valley District Library. Enerdyne of Suttons Bay donated the second telescope..

You may contribute to the fund to help us upgrade and add accessories to the society's telescopes by mailing a check to the GTAS, C/O the society treasurer Gary Carlisle, 1473 Birmley Rd, Traverse City, MI  49686. We are a 501(c)(3) non profit organization. Donations are tax deductible.

Thank You!

Updated: 03/21/18 04:42:22 PM