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Comment by sgt101 | Hacker News Reader

How do the telescopes on Mt Kea protect themselves from the ash? I know that they are on another island some distance from this volcano (I visited a decade or so ago) but does the ash cloud risk transporting damaging particulates to the special glass?

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Mauna Kea is on the big island, north of Kilauea. According to the USGS reports, trade winds are currently blowing the ash clouds south-west, away from the summits of Mauna Kea and Mauna Loa. If the winds shift and start blowing north, I would expect that they'd keep the doors on domes closed. If opened, the ash would not only fall onto the scopes, it would get inside the dome, into all the nooks and crannies, and into sensitive equipment. Just having so much particulate matter in the atmosphere would make observing hard anyway so keeping the doors closed seems to be the best solution.

Just confirming for those that don't know which Hawaiian island is which, Mauna Kea is on the same island as the erupting volcano.

For further clarification, this island is colloquially called "The Big Island", while its official name is "Hawaiʻi" or "Island of Hawaiʻi", which causes further confusion since that's also the state's name (which consists of 8 main islands and many minor islands).

So when news reports refer to "Hawaiʻi", it's hard to be certain what they are talking about without further clarification.

The volcanic ash rarely gets up to that altitude. The reason the telescopes are sited on Mauna Kea is because they are generally above the tropical inversion layer (leading to clear, dry skies). That same inversion layer generally keeps the volcanic emissions down at a lower altitude (not to mention that trade winds generally push the plume in a different direction). When the inversion layer breaks down, there is not much observing anyway as the telescopes are then in the clouds.

Yeah, just to confirm: the current ash cloud has never gotten higher than 12,000 ft, while the telescopes are at 14,000.

Only somewhat related-- you can drive up to the Keck Observatory on Mauna Kea. You need an offroad vehicle, and you have to stop at least once to adjust to the pressure.

I did it once. Driving to an elevation of two miles is terrifying-- and it is cold (I didn't pack a heavy jacket to go to Hawaii), but the view was unbelievable, and it was great to visit the site of so many PBS specials.

The telescope is operated from the University at the base of the mountain so when you arrive there are a reception area and a sort of a cage in the telescope apparatus you can view the telescope from.

I could dig up pictures if anyone is interested but there are more professional ones online I'm sure.

What's the altitude in feet? because that sounds a LOT like my trip to Wyoming, I was at either 8400 or 8600 feet, I don't recall which.

It was near the continental divide if that helps.

The summit is at 14,000ft MSL. It's pretty brutal to go up because unlike when you go to 14,000 ft in e.g. Colorado, here you almost always start from sea level. I always get lightheaded and get a headache every time I go up.

I've been there last year. The oxygen Level at that height is about 30-40% less so you breathe heavier and you move slowly. It's also utterly cold. Everyone is wearing heavy jackets, gloves, and hats.

It was funny seeing some people drive up in their rental mustangs. I can only imagine their brakes cooking by the base of the mountain after that downhill drive.

I suspect they have plans to shut down if the ash swings their way. It probably is a little more complex. If there is significant ash, even just on the ground, then people will track ask into the telescopes. Volcanic ask is nasty stuff in moving parts. Like sandpaper but sharp. I'd consider closing the doors and wait for rain.

Isn't that an observatory like I always know them, e.g. with a roof that can close? That.

Classic HN, how is the scientific equipment holding up? Dust in nooks and crannies? Why I can't even imagine!

Hmm there are humans on the island as well?

We know what happens to humans in volcanic eruptions, nobody needs to ask about it.

Evacuate the area, wait until it stops, rebuild afterward in the same place because people like Hawaii well enough to accept the risk of living on a volcano.

nobody needs to ask about it

Also any human toll is widely reported in the news media, while effects on scientific equipment is not.

In my defence I had assumed that the US authorities will be brilliant at protecting their citizens - especially now that a red warning is out.

The mount kea observatory is a global asset of science - I suspect that it's less important to the US authorities than their people, but it is kinda a global concern.

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