Reminds me of the article from Lensrentals about how much front element scratches affect photo quality. Apparently not very much.

Wait, did they say scratches? They meant a completely cracked front element.

https://www.lensrentals.com/blog/2008/10/front-element-scrat...

Here is a pic showing the bullet holes in the mirror: https://starhopper.org/2020/11/19/a-telescope-with-bullet-ho...

A 1970 historical image: https://historicimages.com/cdn/shop/products/nex48799_1200x....

New York Times: https://www.nytimes.com/1970/02/07/archives/texas-man-fires-...

> An employe of the Mc Donald Observatory, described as drunk by the sheriff and as mentally depressed by his superiors

> Sheriff W. B. Medley said that the shots “completely de stroyed the telescope — it was ruined.” University of Texas astronomers in Austin said the damage was minor.

The telescope is still in use today, and Wikipedia says that the damage effectively reduced the telescope from a 107 inch mirror to a 106 inch mirror.

https://en.wikipedia.org/wiki/Harlan_J._Smith_Telescope

This is no news by any metric, but I found curious that:

1. It only reduced the telescope efficiency by 1%

2. The original report from 1970 is still up!

This is the video that made me aware of the incident: https://www.youtube.com/watch?v=59cw_bDbEqA

https://astroanecdotes.com/2015/03/26/the-mcdonald-gun-shoot...

If you would like to see the bullet holes. Bigger than I imagined based on the telegram.

Last year I built a Hadley telescope, which is a 3d printed structure with some inexpensive optics from China.

https://www.printables.com/model/224383-astronomical-telesco...

One of the things that surprised me, being new to telescopes (and certainly never having built one) was that it was deemed better to leave dust on the optics than to potentially damage them by trying to clean them. The dust just doesn't affect image quality.

I had no ide athat would scale up to gunshots however! Very impressive.

The McDonald Observatory is open to the public (a consequence, as I understand, of it being on the highest-elevation public highway (6,814 ft, 2,077m) in Texas, and hence having right of public access), with both guided and self-guided tours of several of the telescopes / domes, including the 2.7m Smith scope. The damage is visible from the public gallery as I recall.

The scope is primarily used for spectroscopic studies, though it can also be used for direct visual imaging, which might account for why it's even less susceptible to mirror damage than might otherwise be the case.

The region is quite rural, with the nearest settlements being Fort Davis to the southeast and Fort Stockton to the northeast. Among other local attractions are Alpine ("AL-peen"), home to a federal courthouse, and Marfa, a remarkably liberal artist colony.

Remarkably beautiful following a freezing frost in winter time, as well.

Besides the report on mirror damage this telegram also appears to contain observations of "periodic comet Curmumov-Gerasimenko", which had been discovered a year earlier, and happens to be the one ESA's Rosetta mission visited in 2016.

Is the right to shoot at things (in civil life) really that essential in this day and age? When was the last time you required a gun to ensure your safety? Or even to use it as a bottle opener?

I say this having read the mailing list and specifically the part that mentions the mirror is made of fused silica:

What the hell is that mirror made of?

Is this kind of behaviour a well-documented/practical property of silica? I would assume that it'd shatter after any amount of shots and a hammer blow.

I wish there was more information about why the guy shot the telescope. But so far I find nothing.

you can always tell a reflector scope person because they'll just say "all it did was reduce contrast"

When all you've got is a hammer, but then remember that you're carrying a 9mm...

> McDonald Observatory, University of Texas

And all right in the world.

Proven to be vandalproof!