Thread by @emsque

"Hours lost: 6. Reason: Volcano"

Doug Geisler's telescope log from 39y ago today - he was the sole person at Manastash Ridge Observatory when Mt. St. Helens erupted!

I interviewed Doug earlier this year for #TheLastStargazers and got to hear the full tale...

On the night of May 17th 1980 Doug was the only person on the mountain (not uncommon at MRO) and was actually taking his very first night of data for his PhD thesis, starting what was SUPPOSED to be a five-night observing run...

After a beautiful night of observing, he went to bed at about 4am (at this time of year it's getting light out pretty early in the PNW!) and was asleep when the actual eruption happened at 8:32 AM.

Mt St Helens is almost 90 miles from MRO, but the blast was heard states away - he heard a long, low, rolling boom and briefly woke up, but after a night of observing it was easy enough for him to go back to sleep.

Apparently when he did he dreamed about the end of the world.

As the night log notes, when he did wake up around noon and step outside "there is no day. It's completely black; thick inky black", combined with what he called the "fire-and-brimstone" smell of the eruption in the air. He helped remind me why this was the case even 90mi away...

Mt. St. Helens erupted from its north side and produced a huge ash column, which was then blown east-northeast by strong winds at ~60mph. This sent the ash column DIRECTLY over Manastash Ridge Observatory (and Doug), as you can see in satellite images of the eruption:

So. Imagine you're alone on a remote mountain. Pre-cell-phones, pre-wifi. Twelve hours ago it was gorgeous out; then you hear a giant boom in your sleep and wake up to a world of complete and impenetrable darkness.

He figured he was now living in the aftermath of a nuclear war.

He went back inside, battened down the hatches in the building, and started trying to get an emergency broadcast signal on the radio. As he notes in the night log, he picked up music at first, but eventually found a broadcast talking about Mt. St. Helens.

The radio warned people not to drive because the ash would wreak havoc on car innards, so he made sure the telescope was well-covered and spent another night alone on the mountain watching the dust settle (literally) before eventually driving home the next day.

Believe it or not, this is not the only volcano story I've heard for #TheLastStargazers (the observatories in Hawaii have had a few indirect run-ins with volcanic smog and spotting eruptions from the summit) but it's for sure one of the best.

(you can sign up at thelaststargazers.com to get more stories like this along with news about my upcoming book on the tales and adventures of astronomy observing, due out next year!)