If you’re curious about astronomy, you’ve probably wondered how many telescopes are on Mauna Kea. This mountain in Hawaii is famous for its incredible views of the cosmos, and the answer is more interesting than you might think.
Mauna Kea’s summit is home to one of the world’s most important collections of observatories. The clear, dry air and minimal light pollution make it a perfect spot for stargazing. Let’s look at what’s up there and why it matters so much to science.
How Many Telescopes Are On Mauna Kea
As of today, there are 12 major telescope facilities operated by 11 different international institutions on the summit of Mauna Kea. It’s important to note that some of these facilities house multiple instruments or telescopes within a single structure. So, while there are 12 physical observatory buildings, the total number of individual telescope apertures is actually higher.
The Current Roster of Observatories
Here is a list of the telescope facilities currently operating on the summit:
- Canada-France-Hawaii Telescope (CFHT)
- Gemini Northern Telescope (part of the international Gemini Observatory)
- NASA Infrared Telescope Facility (IRTF)
- James Clerk Maxwell Telescope (JCMT) – a submillimeter telescope
- Subaru Telescope (operated by the National Astronomical Observatory of Japan)
- W. M. Keck Observatory (twin telescopes, Keck I and Keck II)
- University of Hawai‘i Hoku Ke‘a Teaching Telescope
- University of Hawai‘i 2.2-meter Telescope (UH88)
- Submillimeter Array (SMA) – an array of eight radio telescopes
- Caltech Submillimeter Observatory (CSO) – (currently decommissioned but structure remains)
- Very Long Baseline Array (VLBA) antenna – part of a continent-wide radio network
- The NASA Kuiper Airborne Observatory previously used a facility here, but it is no longer active.
Understanding the Different Types of Telescopes
Not all telescopes on Mauna Kea are the same. They are designed to observe different kinds of light or energy from the universe.
Optical and Infrared Telescopes
These are what most people picture. They collect visible light and infrared radiation (heat). The Keck telescopes, Subaru, and Gemini are giants in this category. They have massive mirrors to gather faint light from incredibly distant galaxies.
Submillimeter Telescopes
These, like the JCMT and the SMA, detect longer wavelengths of light. They are perfect for studying cold clouds of gas and dust where new stars are being born. They can peer through cosmic dust that blocks visible light.
Radio Telescopes
The SMA and the VLBA antenna are radio telescopes. They collect radio waves from space, which are emitted by objects like pulsars and giant gas clouds. The SMA’s eight dishes work together as one giant telescope, providing detailed images.
Why Mauna Kea is the Chosen Location
Scientists from around the globe compete for time on these telescopes. Why is this mountain so special? Several key factors come together here like nowhere else on Earth.
- Altitude: At 13,796 feet (4,207 meters) above sea level, the summit sits above 40% of Earth’s atmosphere. This means less air and moisture to distort light.
- Dark Skies: Its remote location in the middle of the Pacific Ocean means it’s far from city lights, ensuring exceptionally dark nights.
- Stable Air: The airflow around the mountain is often very smooth, leading to clear, stable images known as good “seeing.”
- Dry Climate: Low humidity is crucial for infrared and submillimeter observations, as water vapor absorbs these types of light.
A Brief History of Astronomy on the Mountain
The first modern telescope on Mauna Kea was the University of Hawai‘i’s 0.6-meter telescope built in 1968. Its success proved the site’s exceptional quality. This led to a wave of construction in the 1970s and later, including the NASA IRTF in 1979 and the CFHT in 1979.
The 1990s saw the arrival of the giants: the twin Keck telescopes (1990, 1996) and the Subaru Telescope (1999). Each new generation pushed the limits of size and technology. The most recent major addition was the Submillimeter Array, completed in 2003.
The Thirty Meter Telescope (TMT) Project
Any discussion about telescopes on Mauna Kea must mention the Thirty Meter Telescope. This proposed next-generation optical telescope has been a source of significant debate and protest since 2014.
If built, it would be one of the largest and most advanced optical telescopes in the world. Its 30-meter primary mirror would collect more light than all the existing optical telescopes on Mauna Kea combined. However, the project faces strong opposition from some Native Hawaiian groups, who consider Mauna Kea a sacred summit. The future of the TMT on Mauna Kea remains uncertain as of now.
How Telescope Time is Awarded
You can’t just buy a ticket to look through the Keck telescope. Time is precious and is allocated through a competitive process.
- Proposal Submission: Researchers from around the world submit detailed proposals for what they want to observe and why.
- Peer Review: Committees of expert astronomers review the proposals. They rank them based on scientific merit, feasibility, and potential impact.
- Time Allocation: The highest-ranked proposals are awarded blocks of observing time, often just a few nights per year.
- Remote Observing: Many astronomers now operate the telescopes remotely from their home institutions, thanks to advanced internet connections.
Major Discoveries Made on Mauna Kea
The telescopes here have fundamentally changed our understanding of the universe. Here are just a few landmark discoveries:
- Confirming the accelerating expansion of the universe (which led to a Nobel Prize).
- Directly imaging planets orbiting other stars (exoplanets).
- Detailed studies of supermassive black holes at the centers of galaxies.
- Mapping the distribution of dark matter in the cosmos.
- Observing the most distant galaxies ever seen, revealing the early universe.
Environmental and Cultural Stewardship
The mountain is also a fragile ecosystem and a deeply sacred place in Native Hawaiian culture. The Office of Mauna Kea Management (OMKM) was established to balance science with preservation. Their work includes:
- Protecting endangered native species like the wēkiu bug.
- Managing access to the summit to minimize human impact.
- Ensuring cultural protocols are respected.
- Planning for the eventual decommissioning and removal of older telescopes to restore the landscape.
This stewardship is an ongoing and critical part of the mountain’s future. All users of the mountain must recognize it’s signifigance beyond astronomy.
Visiting Mauna Kea’s Telescopes
While you can’t control the telescopes, you can visit the summit. The Onizuka Center for International Astronomy Visitor Information Station, located at 9,200 feet, is a must-stop. They offer nightly stargazing programs with smaller telescopes. If you drive to the summit for sunset, remember these important tips:
- Acclimate: Spend at least 30 minutes at the Visitor Station to adjust to the altitude.
- Vehicle: You need a 4-wheel drive vehicle to drive the steep, unpaved summit road.
- Health: The altitude can cause serious health issues. Do not go if you are pregnant, have heart or breathing problems, or have recently scuba dived.
- Respect: Stay on marked roads and paths. Do not disturb any natural or cultural features.
The Future of Astronomy on Mauna Kea
The landscape of astronomy is evolving. While Mauna Kea remains a premier site, new extremely large telescopes are being built in Chile. The future of the mountain will likely involve maintaining and upgrading its existing world-class facilities while carefully considering its cultural and environmental carrying capacity. The decommissioning of older telescopes, like the Caltech Submillimeter Observatory, is part of this process to reduce the overall footprint.
FAQ Section
How many telescopes does Mauna Kea have?
There are 12 major observatory facilities on the summit, housing more than a dozen individual telescope instruments.
What is the largest telescope on Mauna Kea?
The twin Keck telescopes are the largest optical/infrared telescopes, each with a primary mirror 10 meters in diameter. The Subaru Telescope has a single 8.2-meter mirror.
Can the public use the telescopes on Mauna Kea?
No, the research telescopes are not for public use. However, the Visitor Information Station offers public stargazing with their own telescopes, and some observatories provide virtual tours and online data.
Why are they building more telescopes if there’s already many?
Newer telescopes, like the proposed Thirty Meter Telescope, offer dramatically more powerful capabilities. They can see fainter objects in greater detail, allowing scientists to ask new questions about the universe. However, this expansion is balanced with cultural and environmental concerns.
Is Mauna Kea the best place for telescopes?
It is one of the very best sites on Earth for optical, infrared, and submillimeter astronomy due to its unique atmospheric conditions. Other locations, like the Atacama Desert in Chile, offer similar advantages for different reasons.
Who owns the telescopes on Mauna Kea?
The telescopes are owned and operated by a mix of international consortia, universities, and government agencies. The land is leased from the State of Hawai‘i by the University of Hawai‘i, which then subleases to the observatories.
So, when you ask how many telescopes are on Mauna Kea, the number tells only part of the story. It’s a place where cutting-edge technology meets ancient culture under the clearest skies on Earth. The work done here continues to shape our understanding of where we came from and what’s out there in the vast cosmos. Whether your an astronomy enthusiast or just someone who looks up at the stars, the legacy of this mountain touches our collective knowledge.