Mauna Kea on the Big Island of Hawai'i
with a light dusting of snow. Viewed from Hualalai Mountain
The elevation and location of Mauna Kea have made it an important location for atmospheric and astronomical observations. The summit is above approximately 40% of Earth's atmosphere and 90% of the water vapor, allowing for clearer images. Additionally, the peak is above the inversion layer, allowing up to 300 clear nights per year. Also, at 20°N latitude, much of the southern sky is visible. The summit is widely known for its observatories built by many nations, the best seeing disk with a measurement of ~0.2 arcseconds.
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