By Jimmy Westlake, professor of physical science, Alpine Campus
There are lots of reasons to visit Hawaii, our 50th state, but “seeing the world’s largest telescopes” is probably not on most folks’ list of things to do. To an astronomy enthusiast like me, though, the Big Island of Hawaii is astronomy paradise.
It is not by accident that the largest telescopes operating in the world today sit atop Mauna Kea, the inactive volcano that rises 13,803 feet above the waves far below. On this little speck of land in the middle of the vast Pacific Ocean is one of the best, if not THE best, places to view the starry sky with a telescope.
The way that the air currents flow up and over this hump in the middle of the ocean without turbulence creates very steady star images. Instead of flickering and flashing and twinkling, the stars from atop Mauna Kea are sharp and steady, forming crisp, clear images for astronomers. “Twinkle, twinkle little star” does not apply atop Mauna Kea.
A second major reason astronomers flock to the Big Island is because they need extremely dry air to study the infrared energy coming to us from the stars. Water vapor in the air absorbs the invisible infrared energy from starlight, making it virtually impossible to study from most places on Earth. It might seem odd that one of the driest locations on Earth sits in the middle of the Pacific Ocean, surrounded by water, but it is true. The summit of Mauna Kea typically gets about one inch of precipitation each month of the year. Combine extremely calm air with extremely dry air at one location and you have arguably the best observing site on Earth.
The biggest eyes peering out at the universe from Mauna Kea are the Keck Twins. Each giant Keck telescope has at its heart a 10-meter (32.8 foot) diameter segmented mirror, composed of a mosaic of 36 hexagonal mirrors that function as one. The twin Keck telescopes can then combine their individual images into a single super-duper image.
The largest single-mirror telescopes atop Mauna Kea are the 8-meter Subaru and Gemini North telescopes. Subaru is the National Astronomical Observatory of Japan and it barely nudges out the Gemini North telescope as the largest single mirrored telescope on Earth – Subaru is 8.2-meters in size compared to Gemini’s 8.1 meters. The USA has partnered with the UK, Canada, Chile, Argentina, Australia, and Brazil to build and operate the Gemini North telescope in Hawaii and its Gemini South twin in Chile. The amazing adaptive optics systems of these glass behemoths can effectively cancel out atmospheric twinkling by rapidly distorting the shape of their mirrors to produce images that challenge or surpass those of the Hubble Space Telescope, orbiting 600 kilometers above Earth.
Coming soon to the summit of Mauna Kea, will be the next generation of giant astronomical telescope. Last summer, Mauna Kea was chosen as the location for the new TMT – the Thirty Meter Telescope! The TMT will build on the success of its predecessors, the Keck twins, and will use a 30-meter diameter mosaic of 492 individual mirror segments. Scheduled for completion in 2018, the TMT will no doubt catapult our understanding of the universe far beyond where the Kecks, Subaru, Gemini, and even the HST have taken us.
Anyone with a 4WD vehicle can access the summit of Mauna Kea before nightfall, however, guided tours of the observatories must be arranged in advance. The Visitor Information Services (VIS) building, located at the 10,000 foot level of the mountain, is accessible to all vehicles and houses a mini-theatre, a wonderful gift store, and provides free public telescope observing until 10:00 PM every night of the year, weather permitting. Complimentary hot chocolate and hot coffee will help ward off the shivers in the cold, night air.
In my book, any trip to the Big Island is not complete without a visit to the giant eyes of Mauna Kea.
Professor Jimmy Westlake teaches astronomy and physics at Colorado Mountain College’s Alpine Campus. He is an avid astronomer whose photographs and articles have been published all around the world. His “Celestial News” column appears weekly in the Steamboat Pilot newspaper. His “Cosmic Moment” radio spots can be heard on local radio station KFMU. Also, check out Jimmy’s website at www.jwestlake.com.