- Date: 19 Dec 2016
- Comments: (0)
- Categories: For Everyone, Fun Stuff
Welcome to Gemini’s 12 Days of Solstice! This is a joyous countdown to the longest, or shortest (depending on which hemisphere you live in) day of the year! Visit our blog each day from December 10 – December 21 for Gemini-themed crafts, cartoons, playlists, videos and much, much more.
Day 10: Gemini Fun Facts
Here at Gemini Observatory we measure diameters, heights, weights and thickness in meters, centimeters, tons and microns. But sometimes it is just more fun to measure them in walruses! For today’s gift, check out these fun facts about Gemini Observatory and its telescopes.

“I hope these fun facts help you visualize Gemini Observatory and its telescopes!” -Anonymous male Atlantic Walrus
- A single 8.1 m Gemini primary mirror weighs about 24 tons. That is the weight of 24 male Atlantic walruses or 2526 female Andean foxes!
- The Gemini primary mirrors are 8.1 meters in diameter and 20 centimeters thick. It would take 1,355 soccer balls to cover the entire surface but only 1 soccer ball to make up its height!
- The secondary mirrors are 1.0 meters in diameter. 14 tennis balls laid end-to-end would cover its diameter!
- Gemini North and South are the only large telescopes in the world with silver-coated primary mirrors. The coating of silver is only 1/2000 the thickness of a human hair!
- The vents on the walls of the dome can be opened as wide as 10 meters. This is the length of the end zone on an American football field or a tad smaller than the distance from penalty spot to goal line on a soccer field!
- Gemini North sits atop Maunakea, which when measured from the ocean floor is the tallest mountain on Earth at 10,230 meters. That is taller than Mount Everest by almost 5 Eiffel Towers!
- Collect all of our data centers together and you have 200 terabytes of data. This is the same as 57,000,000 million mp3s or 380 years of continuous music!
Don’t forget to check back tomorrow for the next installment of Gemini’s 12 Days of Solstice countdown!