The following are some notes on rules to observe and words of caution and advice for your visit to observe the Subaru Telescope.

Rules You Must Observe

  • Only observers who applied in advance and have signed permission forms will be admitted to observe the Subaru Telescope. Requests are not accepted on-site, so please do not bring along persons not listed in the request submitted in advance.
  • The maximum number of observers at any one time is eight persons.
  • For health and safety reasons, groups of high-school students are not accepted on observation tours of the Subaru Telescope.
  • Follow the instructions of your Observatory guide at all times. Pay especially close attention to safety explanations, instructions about the observation route you will follow and instructions given in the event of emergency evacuation, and comply with those instructions fully.
  • Do not enter any other than the designated locations.
  • If an emergency occurs, or if the Observatory guide judges that continuation of the observation tour would obstruct the operation of the telescope, the tour may be immediately terminated. In such cases, observers must comply immediately with the instructions of the guide.
  • Arrive at the appointed assembly location on time.If your group is 15 minutes or more late to arrive, and no notice is provided, your tour will be cancelled. Even if notice is received, your tour may be cancelled if necessary to avoid obstructing the operation of the telescope or the next tour group.
  • The dome of the telescope is cooled. Observers are asked to take necessary measures to protect their own health during observation inside the dome. Please cooperate in ensuring that your observation tour concludes within the time allotted.
  • Be considerate of the environment of the entire peak area. Follow the rules and act appropriately in the Subaru Telescope facilities.Please be aware that if rules are not followed the NAOJ Observatory may cease offering observation tours.
  • If you intend to publish your tour in articles, photos, etc., and such publication exceeds the normal scope of personal use, the permission of the Observatory is required in advance.

Special cautions regarding observation of the facilities atop Mauna Kea and general cautions and recommendations

Special Cautions

Mauna Kea has an elevation of 4,200m. Air pressure at the peak is only 60% of the pressure at sea level. Because of the thinness of oxygen in the atmosphere, visitors to the facilities at the peak are in danger of altitude sickness.The high-altitude conditions at the peak may aggravate some people’s existing medical conditions for this reason persons aged 16 and under, persons in uncertain health condition and pregnant women are not admitted to observation tours of the Subaru Telescope.

General Cautions and Recommendations

Conditions at the peak can cause oxygen deficiency, leading to degradation of metabolic function. For this reason, please consider the following cautions and recommendations.

  • Smoking and consumption of alcohol are strictly prohibited within the grounds of the Subaru Telescope. Visitors are advised to avoid smoking and consuming alcohol for 48 hours before their visit.
  • The difference in air pressure can cause gas to accumulate in the digestive tract. On the day before your visit, please avoid excessive consumption of foods that generate gas (beans, cabbage, onions and other foods that induce flatulence).
  • Dehydration can leave you vulnerable to altitude sickness. You are advised to consume large amounts of water.
  • Do not go scuba diving in the 24-hour period before your visit.
  • To accustom your body to the altitude, please rest at the Mauna Kea Visitor Information Station for at least 1 hour on your way up the mountain.
  • Do not try to hurry when you are inside the Subaru Telescope facilities. Avoid crouching down and standing up suddenly, as when picking up something you’ve dropped.
  • If you feel ill, do not ignore it. Tell an Observatory staff member about your condition. If you feel ill on the day of your visit, we recommend that you cancel the visit. The nearest medical facilities from the peak are a 11/2- to 2-hour drive down the mountainside, and no professional medical staff are stationed at the Observatory.
For your reference: Symptoms of altitude sickness
  • Most people experience some degree of headache, drowsiness and/or shortness of breath while inside the dome, as well as coldness due to the low temperature of the dome interior.
  • Effects on the central nervous system: Instability in level of consciousness (drowsiness, confusion, loss of mental flexibility); unintelligible speech; severe headache; severe anxiety
  • Respiratory system: Severe shortness of breath, shallow breathing during speech; difficulty breathing; severe shortness of breath even while resting; unusually rapid breathing (for example, 40 inhalations per minute or more); coughing with frothing at the mouth, or expulsion of phlegm mixed with blood
  • Circulatory system: Increase or decrease in pulse rate; chest pain, heart attack
  • Other symptoms that sometimes accompany altitude sickness: Lack of coordination among parts of the body, particularly in the muscles; loss of balance; sluggish walking; impairment of vision (loss of peripheral vision); numbness and lack of sensation in extremities; stomach cramps; severe nausea; vomiting
What to Wear
  • To maintain the performance of the Subaru Telescope, the temperature inside the dome is climate-controlled to a constant 0°C. It has been pointed out that one important way of preventing altitude sickness is to maintain body temperature. To protect yourself from the cold as well as the wind outdoors, wear warm outerwear that covers the entire body. Wear gloves, as the handrails on the observation route are cold. Please note that warm clothing is not available for borrowing or rental in the Subaru Telescope facilities.
  • If an emergency occurs in the Subaru Telescope building, you may be asked to exit via a stairwell that is almost vertical. For this reason you must wear footwear that is securely fastened. Please be aware that if you arrive wearing rubber sandals or other loose footwear, you may be refused entry to the dome for safety reasons.
  • Yellow helmets will be distributed to all observers. Please wear these helmets for the duration of your tour.
Access to the Peak of Mauna Kea
  • There is a road to the peak of Mauna Kea, but there is no public transportation authority with jurisdiction over it.
  • Visitors who arrive at the peak of Mauna Kea by other than the means listed above (for example, persons arriving by taxi) will not be permitted to join the observation tour.
  • The road upward from MKVIS is unpaved. It is impassable without a four-wheel-drive vehicle.
  • The speed limit on the road upward from MKVIS is 25mph (40kph). The grade is steep, so you are advised to keep your vehicle in low gear when descending to avoid excessive speed.
  • Large vehicles regularly travel along the unpaved roads to carry out maintenance. When overtaking these vehicles or passing them in the opposite direction, drive slowly, follow any instructions from the drivers of the large vehicles, and drive with caution.
  • The mountainsides often become foggy, making visibility worse than ever. At such times exercise special care regarding your speed and surrounding conditions.
  • To preserve the natural environment as well as the environment for astronomical observation, a speed limit of 5mph (8kph) is applied to the roads nearby the Subaru Telescope (see map). Please reduce your speed and obey the speed limit.
  • At the speeds listed above, the drive from MKVIS to the Subaru Telescope should take about 30 minutes.
  • When you park your car, please use the designated parking area on the paved section of road on the slope outside the Subaru Telescope dome. Observation visitors are asked to enter and exit through the doors between the outside of the dome and the elevator. Please do not enter any unpaved areas, whether by car or on foot.
  • The distance from the City of Hilo on the east side of the island, where the mountaintop facilities of the Subaru Telescope are located, to the City of Kona on the west side of the island, is between 120km and 160km (80–100 miles). The distance from the center of Hilo to the peak is about 70km (45 miles). Including a one-hour rest halfway up the mountainside, the drive should take between 31/2 and 4 hours. Depending on the traffic in and around Kailua and Kona, it may take a little longer.
Other Notes
  • The upper part of the dome of the Subaru Telescope functions as part of the telescope; it does not have the character of a separate building. Also, accessibility is not established in all areas. If you use a wheelchair, please contact the Operation Center in advance.
  • While in the dome, you must wear one of the helmets available for lending to visitors.
  • There are no washroom facilities along or near the observation route. Please take care of your washroom needs at MKVIS or in the simple toilet facilities just before the peak.
  • Please do not consume food or beverages inside the facilities of the Subaru Telescope. You may carry drinks to maintain your health, provided that you carry and manage them yourself.
  • Take all of your garbage with you when you depart.
  • The Observatory does not offer a lost-and-found service. Please take sufficient care of your belongings. Be aware that it is especially easy to forget things on the peak.
  • When walking around the Subaru Telescope on the peak, please walk carefully and stay on the paved section. Volcanic ash and lapilli (small stones that fall from the sky in a volcanic eruption) are specially placed to support the performance of the telescope; please do not trespass in these areas.
  • Teachers planning to lead groups of students as a school function are asked to read thoroughly the page entitled, “Lectures at Hilo base facility

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