Custer Institute and Observatory is Long Island's oldest public observatory - open from 7 pm to midnight on Saturdays! 

Explore the night sky with our volunteers, powerful telescopes, tours, and live events.

Silhouette of a person under a colorful night sky filled with stars and the Milky Way.

Join us every Saturday night for public observing sessions, where you can explore the cosmos through our powerful telescopes.

When the skies are clear, our knowledgeable volunteer staff will guide you on a tour of the stars, planets, and beyond.

Saturday Night Public Observing
Doors open at 7 PM
Observing from dark until midnight (weather permitting)

All observing takes place outdoors—please dress appropriately. Seasonal hours and times of darkness may affect skywatching times.

Learn more

EVENTS

Outdoor Events: Most events take place on our lawn. We encourage you to bring a blanket or chair to make your experience more comfortable.

Rain Dates: Rain dates (when necessary) will be noted on our website, social media, and/or Eventbrite for your convenience.

WINTER WONDERS OF THE NIGHT SKY

Saturday, December 13 6:00pm & 8:00pm

Register

Learn how to explore and navigate the winter night sky, including the constellations visible this season and stories behind them!

Randall DiGiuseppe, Custer lifetime member and presenter, will be your guide to the awe-inspiring objects that grace our winter night sky such as the Pleiades, Orion's stars and nebulae, and other winter constellations. The event will begin with a talk indoors followed by guided observing outdoors to view some of the objects covered during the presentation. Observatory staff will also provide tours of the night sky (weather permitting) through the many telescopes on site, including the apochromatic Zerochromat telescope in our historic observation dome. Bundle up, look up and take in what our winter night sky has to offer. Then warm up inside with a cup of hot tea or cocoa!

This event is open to everyone. Just bring an inquisitive mind and your imagination.

Randall DiGiuseppe is a professional artist, lecturer, telescope builder and amateur astronomer for over four decades. He is a lifetime member of the Custer Institute and Observatory and recipient of the Astronomical League’s Messier Award. He conducts lectures on the dynamics, history and art of the night sky throughout the country.

$5 Adult, $3 Children Under 16, Observatory Members FREE. Your donations make it possible to offer programs like these and are greatly appreciated. Due to limited space, registration is strongly encouraged.

PROGRAMS + RESOURCES

  • Astronaut on the moon holding a yellow umbrella with Earth in the background.

    WEATHER

    Clear Skies Ahead!

    Find the latest weather forecasts tailored for astronomers, including cloud cover, precipitation, dewpoint, wind conditions, and Moon phases. Our easy-to-read key helps you decide if it’s a perfect night to bring out your telescope!

    TODAY'S WEATHER
  • Silhouettes of musicians and text "Music Under the Stars The Music Project at Custer Institute & Observatory."

    THE MUSIC PROJECT

    Bring music and stargazing together at Long Island’s oldest public observatory, tMP blends the performing arts with science and discovery. A unique stargazing experience follows each performance where audiences are invited to explore the night sky with guidance from our expert volunteer staff, using our historic observation dome and an array of on-site telescopes.

    LEARN MORE ABOUT TMP

  • WHAT'S UP?

    Skywatching highlights each month, provided by NASA.

    VIEW VIDEO
  • Telescope on tripod with accessories in a grassy field with trees in the background.

    RESOURCES

    Whether you're a seasoned astronomer or just starting your journey into the cosmos, our collection of resources will help guide you.

    RESOURCES
  • Blue background with white and gold text reading "Custer Institute & Observatory Scholarship Program" and a stylized star and comet graphic in the top left corner.

    SCHOLARSHIP

    Supporting the Next Generation of Scientists & Innovators. Available to High School Seniors throughout the North Fork.

    LEARN MORE
  • Illustration of Custer Institute Observatory with text "Honey of the Stars, 100% Pure Local Honey, Custer Institute Observatory, Southold, New York" and "Custer HoneyBee Club" on a building, under a starry sky.

    HONEY BEE CLUB

    Custer's Honey Bee Club is an educational program focused on environmental sustainability and honeybee stewardship.

    Send an email to learn more.

    LEARN MORE & JOIN

Support the North Fork Dark Sky Coalition

Take action to protect our night skies:

  • Pledge to turn off unnecessary lights and spread awareness,

  • Update Your Lighting by using dark sky-friendly fixtures and warm-toned bulbs, and

  • Become a Partner to advocate, educate, and support local Dark Sky initiatives.

Take the pledge and join the North Fork Dark Sky Coalition

Learn more
Night sky with Milky Way over waterfront building and boats at a dock.

AFFILIATIONS + SUPPORTERS + PARTNERS

  • Ridgewood Savings Bank logo with acorn icon.

    Ridgewood Savings Bank

    SPONSOR

  • "The Weakley Foundation" text on a white background.

    The Weakely Foundation

    SPONSOR

  • Logo featuring stylized letters 'S' and 'S' with text 'North Fork Side By Side' in a decorative font.

    North Fork Side By Side

    SPONSOR

  • "The Joe & Hellen Darion Foundation" text in black letters on a white background

    The Joe & Hellen Darion Foundation

    SPONSOR

  • Logo of Amateur Observers' Society with a star and curved line design.

    Amateur Observers' Society

    PARTNER

  • Suffolk County Office of Economic Development & Planning

    SPONSOR

  • North Fork Dark Sky Coalition logo with cloud and crescent moon icon on dark background.

    North Fork Dark Sky Coalition

    PARTNER

  • Pro Bono Partnership logo on blue background.

    ProBono Partnership

    SPONSOR

  • "The Harold Family Foundation" text in black lettering on a white background.

    The Harold Family Foundation

    SPONSOR

  • Logo of The New York Community Trust on a green background with yellow and white text and decorative lines.

    The New York Community Trust

    SPONSOR

Stay in our universe.

Sign up for exclusive updates and news on events, programs, lectures, and live music

—no black holes of spam, just stellar content
delivered to your inbox. Subscribe.