University of Hawaii Instutute for Astronomy
Mauna Kea
Visiting Mauna Kea

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Visiting Mauna Kea Observatories

If you would like to visit Mauna Kea Observatory we recommend that  you begin at the Visitor Information Station of the Onizuka Center for International Astronomy at the 9,000-foot level on the Mauna Kea access road.  At the center you can  learn about the mountain, the telescopes, and the Universe, buy souvenirs and view the stars after dark through our portable telescopes. 

You can also drive to the 14,000-foot summit of Mauna Kea to view the domes of the main observatory itself, but you need to be aware that; 

  • Ordinary vehicles cannot cope with the steep, unpaved road; you will need to obtain a four-wheel drive vehicle, or take a commercial tour
  • There are no opportunities to "look through" the telescopes at the summit, and visitors are not allowed at the summit after dark.
  • The road up the mountain can be dangerous, particularly in bad weather.
  • The high altitude of the observatory carries serious health risks and routinely  impairs physical and mental activity.
  • The Keck observatory and the UH2.2m telescope have visitors galleries from which the telescope may be viewed at certain times. The Keck gallery is generally open 10am - 4pm Mon-Fri, while the UH 2.2m is usually open 9.30am - 3.30pm Mon-Thu.


Click for Big Island mapsMauna Kea is situated on the Big Island of Hawaii. It can be reached  from Route 200--the narrow and winding Saddle Road, so named because it runs between the two major volcanic mountains, Mauna Loa and Mauna Kea, at an elevation of 2,000 m (6,600 ft). A paved road leaves the Saddle Road at Mile 28 and winds its way up to the lower slopes of Mauna Kea to the Visitor Information Station (VIS) at the Onizuka Center for International Astronomy (OCIA), which is the mid-level altitude acclimatization center for scientists and technicians. The distance from Hilo to the OCIA is 34 miles (55 km), with the average travel time being 1 to 1-1/2 hours.

Visitor Information Station

 The OCIA Visitors' Information Station (VIS), about 20 minutes from the turnoff from the Saddle Road, is between the construction camp area and the mid-level dormitories. 

During the day while the VIS is open: there are videos to watch, astronomy magazines to read, displays to view, handouts to browse through, and several computers with Mauna Kea and astronomy software running.

The center owns several high quality portable telescopes through which the night sky may be viewed by visitors. One of the telescopes has a spectrograph and a Coronado H-alpha scope mounted on it so that visitors can view sunspots and stellar spectra during the daytime.

  • Summit Tours are held on Saturday and Sunday from 1:00 to 5:00 PM.
  • Stargazing Programs are held every night from 6:00 to 10:00 PM

Driving on Mauna Kea

Mauna Kea is a very remote location. It has no public accommodations, food, or gasoline service. The observatory buildings are usually closed to the public. There are no permanent restrooms above the Visitor Information Station. The only public telephone above Hale Pohaku is an emergency phone in the entrance to the University of Hawaii 2.2-m Telescope building. Vehicles should be in good working condition with good brakes and sufficient fuel to return to Hilo or Waimea. Emergency services, including medical assistance, may be two hours away. 

The road above the OCIA to the Mauna Kea Observatories is unpaved, rough, steep, winding, and dangerous. Only four-wheel-drive vehicles are permitted above the OCIA. The road can be traversed in about half an hour in good weather, but extreme caution must be exercised when driving it, particularly on the descent. Use low gear and be on the lookout for slide areas and for loose gravel. Do not drive over 25 mph. Use headlights if it is foggy. The switchback section of the road above OCIA is particularly hazardous during the hour after sunrise and the hour before sunset, because of the low elevation of the Sun - in several sections of the road, you must drive directly towards the Sun, so it is very difficult to see oncoming traffic

Weather on Mauna Kea

Visitors to Mauna Kea should prepare themselves for severe weather, especially during the winter months, when heavy storms commonly deposit several feet of snow. Minimum nighttime winter temperatures at the summit are around -4 degrees Celsius (25 degrees Fahrenheit); maximum daytime temperatures are about +4 degrees Celsius (40 degrees Fahrenheit), but wind chill and the high altitude can make it seem much colder. Between April and November the weather is milder, with daytime temperatures varying from freezing to almost 15 degrees Celsius (60 degrees Fahrenheit).  

The Mauna Kea Weather Center at University of Hawaii is currently developing specialized weather prediction tools for Mauna Kea and its immediate surroundings.  These predictions help astronomers to plan their observing to make the most efficient use of each night's atmospheric conditions.

Health hazards on Mauna Kea

Altitude sickness

At the summit elevation of 13,796 feet (4,200 m), the atmospheric pressure is 40 percent less than at sea level. Less oxygen is available to the lungs, and acute mountain sickness is common. Symptoms include: headaches, drowsiness, nausea, shortness of breath, and poor judgment. 

The intensity of these symptoms may be lessened by spending at least a half hour at the Visitor Information Station (altitude 9,200 feet or 3,000 m) before traveling to the summit..

Children under 16, pregnant women, and people with respiratory, heart, or severe overweight conditions are advised not to go higher than the OCIA Visitors Information Station.

Scuba divers must wait at least 24 hours after their last dive before traveling to the summit.

High altitudes can also cause the life-threatening conditions pulmonary edema (fluid in the lungs) and cerebral edema (fluid on the brain). Descend immediately if any of these symptoms appears:

  • severe headaches, 
  • vomiting, 
  • breathing difficulties, 
  • coughing, 
  • blue lips or fingernails, 
  • disorientation,
  • extreme drowsiness that may lead to coma. 

Drink Plenty of Water

The summit is usually extremely arid. To prevent dehydration, you should drink plenty of water prior to and during your visit to the summit of Mauna Kea.

Sunburn and Eye Damage

The summit is above much of the atmosphere that blocks the sun's ultraviolet radiation. This presents a risk of serious sunburn and eye damage, particularly when there is snow on the ground.

Impaired Judgment

High altitude causes impaired reasoning and drowsiness. Alcohol will further impair judgment and driving abilities.

Imiloa Astronomy Center of Hawaii

The Imiloa Astronomy Center of Hawaii (formerly the Mauna Kea Astronomy Education Center - MKAEC) is a $28 million planetarium, museum and educational resource on the University of Hawaii at Hilo campus..

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