Mauna Kea is one of the darkest locations in Hawaii, USA — a Bortle Class 2 sky that unlocks satellites completely invisible from any city. Live pass times are computed for your exact location here.
A Bortle 2 sky has a naked-eye limiting magnitude of approximately 7.2 — two to three magnitudes deeper than an urban sky, revealing satellites that simply don't exist to city observers.
| Satellite | Magnitude | From here | Notes |
|---|---|---|---|
| ISS (Zarya) | mag -4.0 | ✓ Visible | City-visible. Magnitude up to −4, dazzling even under street lights. |
| Tiangong (CSS) | mag -2.0 | ✓ Visible | City-visible. Slightly dimmer than the ISS with an orange tint. |
| Hubble (HST) | mag +1.5 | ✓ Visible | Visible here — needs a dark sky. Distinctive blue-white colour. |
| AST BlueBird-6 | mag +1.5 | ✓ Visible | Visible here — as bright as Hubble. Often spotted in pairs. |
| BlueBirds 1–5 | mag +4.0 | ✓ Visible | Visible here under this Bortle 2 sky. A dark-sky exclusive target. |
| Starlink (single) | mag +5.0 | ✓ Visible | Individual Starlinks reachable here with Bortle 2. |
Magnitudes are peak naked-eye brightness. Visibility also depends on elevation angle, phase, and local transparency.
Mauna Kea is rated Bortle Class 2 on the nine-point scale — an exceptionally dark rural sky. At this level the limiting magnitude for the naked eye is approximately 7.2, meaning you can see stars and satellites far fainter than in any urban setting.
Yes — and far more than you can from a city. The ISS and Tiangong are visible from everywhere, but Mauna Kea's Bortle 2 sky unlocks the Hubble Space Telescope, all six AST BlueBird satellites, and individual Starlink satellites that are simply invisible against a lit urban sky. Use the live pass times above to plan your session.
At Bortle 2, all six AST BlueBird satellites become reachable naked-eye targets — something no city observer can achieve. Individual Starlinks in their operational shells are also visible, whereas from a city you only see the bright post-launch trains. Hubble (mag 1.5) is another dark-sky exclusive: easily found here, nearly impossible from suburbs.
October – March offers the best conditions. Northern winter nights are longest, temperatures are cold but skies are crisp and transparent. Avoid June – July when longer twilights reduce the available darkness window. Moon phase matters enormously at dark sky sites — a new moon week during October – March is the prime target.
Mauna Kea is located in Hawaii, USA, at 19.82°N, 155.47°W, approximately 55 km from Hilo. Check access conditions and any permits required before visiting, particularly for national parks and protected reserves.
Yes — from the Northern Hemisphere, Polaris and the Big Dipper dominates the overhead sky, and the Milky Way core arches in the southern direction. At Bortle 2, the Milky Way casts a visible shadow and complex dust lanes are clear to the naked eye — the same darkness that reveals faint satellites.
For all dark sky sites worldwide: Dark Sky Site directory.