An Observatory on an Active Volcano

by Tony on December 30th, 2007

Did you know there was an observatory on an active volcano?

Phulubig Since 1960, the High Altitude Observatory has operated the Mauna Loa Solar Observatory. It is accessible only by a tiny paved road off of the Saddle Road on the big island of Hawai’i. The road is virtually invisible and you’ll miss it if you blink, I know the road is coming up if I see Pu’u Huluhulu off to the left (see image at left).

This is one tiny road too. It is a one lane road with a line of paint dribbled down the center by observers sitting in the back of a truck holding a paint can with a hole in the bottom. That line is pretty damned important, especially while driving through thick clouds or snow.

You need special permission to get up there (not the road, anyone can drive up there, I’m mean to the observatory building itself), but the observers are very nice and if you call before you go up, they’ll be happy to give you a tour. You can drive all the way up to the Mauna Loa Observatory (operated by NOAA) until you get to a gate. At that point you can’t go further without permission.

Working at HAO for 15 years, I’ve been up there many times. It’s a great way to explore Hawai’i off the beaten path.

As you approach the road, the landscape looks like the moon, and it is a very cool place. At 11,000 feet the observers operate a variety of instruments designed to image the Sun (and the corona) at a variety of wavelengths.

This is the ONLY ground based telescope imaging the solar corona on a daily basis. Every three minutes, a linear CCD array scans around the occulted disk of the Sun to take images like this:

Mk4Corornagraph
Image Credit: Mauna Loa Solar Observatory

In 1984, the volcano erupted, blocking the road. Ever since that time, the MLSO observers park the car facing down the road to ensure they get out fast. In 1986, they put up a lava barrier:

Image Credit: Mauna Loa Observatory