May 25th - May 29th 2017

This year's theme: The Day the Sun Disappears

Astronomers! Whether you are a beginner or an advanced amateur astronomer, we welcome you to attend the RTMC Astronomy Expo, Memorial Day weekend just outside of Big Bear City
  • See the stars from the clear air of YMCA Camp Oakes
  • Learn of new developments in amateur telescope making
  • Check out commercial telescopes and equipment brought by vendors for observers
  • Listen to excellent presentations covering observing, telescopes, and getting started in astronomy
  • Enjoy all the swap meet’s astro-goodies on both Saturday and Sunday
  • Socialize and observe with friends


On August 21, 2017, the moon's shadow will sweep across North America. For the first time since 1979, the moon will completely hide the Sun over the United States. It will be The Day the Sun Disappears. The excitement in advance of this event will escalate exponentially with both amateur astronomers and the general public getting involved. The eclipse will be a national and international news story. The 2017 EXPO will focus on this huge astronomical event with speakers, vendors and our keynote speaker: Mr. Eclipse.

Mr. Eclipse is, of course, Dr. Fred Espenak, retired after 30 years as NASA astrophysicist at Goddard Space Flight Center. He now maintains NASA’s eclipse website at As a sought-after author, speaker, eclipse-chaser, photographer, and eclipse expert, Dr. Espenak will bring us the latest and best experiencing the upcoming 2017 solar eclipse. You can also check out his personal website at

To learn More About the KEYNOTE click here more

Astro-Imaging Workshop with Josh Smith

We are back with another outstanding imager presenting an extensive workshop on equipment, acquisition & processing celestial images. Josh Smith, from the Astro Imaging Channel, will be coming from Florida to share his expertise.

As an astro photographer, Josh enjoys diving deep into every aspect of the hobby, pushing processing techniques to the limits & finding new ways to bring out the faint stuff. As an engineer, his heart is always in modifying his gear to get every last ounce of performance possible. If you have seen him on the Astro Imaging Channel, you know he has an easy style, responding to the beginner to advanced. He is one of the founders of The Astro Imaging Channel, a weekly class & web space devoted to sharing all things astrophotography with the broader community including processing tutorials, hardware reviews, software intros, and more. You can find out more about Josh, see his gallery, and listen to a few of his tutorials on The Astro Imaging Channel on Google+ or at

This is a premium workshop, available to no more than the first 50 to register. The workshop will be from 10:00 to 4:00 Sunday, with breaks for lunch. Through the years, these RTMC AE Premium Astrophoto Workshops have been over-booked by early April, so be sure to sign up early!


The 49th annual RTMC Astronomy Expo will take place from Thursday, May 25th through Monday, May 29th, 2017. It will be held at YMCA Camp Oakes, five miles southeast of Big Bear City, California


Pre-registration is available before May 7. After May 7 you may register on-site at premium prices. You may register using a printed registration form or on-line with PayPal


Vendors include any business, club, organization, or individual, who wishes to setup a booth and sell any commercial item or service. Clubs can set up for free if they are not selling. A Sponsor has donated to RTMC and is given special recognition both on this website and at the EXPO

Welcome to RTMC

Letter From The President

Welcome to our 49th RTMC! This year we will be highlighting The Day the Sun Disappears...The solar eclipse of August 21,2017. Our main speaker is Dr. Fred Espenak, Mr. Eclipse, himself. Other engaging speakers will talk on a variety of subjects. If you are a beginner, we have programs with our Beginner's Corner. Around the camp you will enjoy solar observations during the day and an awesome star party at night featuring large telescopes under mostly moonless skies. Jupiter will be near the meridian in the evening. Saturn will rise by midnight and Venus will be visible just before dawn. Of course, our vendors will tantalize you with their incredible products. So come and be part of the RTMC tradition and experience the sky with friends