mirror

Most people know that Americans have a special relationship with their flag, and with firearms. This sometimes pose challenges and some interesting solutions when expensive astronomical equipment needs to be transported by rail or road to remote locations.

Sometimes, people are taking pot shots at containers on cargo trains and at freight trucks on highways in the US (or in rural areas elsewhere, for that matter). It’s not an uncommon occurrence. But naturally one wants to avoid this when transporting sensitive equipment.

During the construction of the Large Binocular Telescope in Arizona in 2003, the two 8.4m mirrors needed to be transported from the Richard F. Caris Mirror Lab in Tucson (they do public tours and it’s worth visiting), to Mt. Graham, the site of the telescope. Transporting such large chunks of glass is no small feat and it requires great care, to ensure that the mirror is not shaken, bent, or otherwise damaged during transportation. The transport crew, mainly being veterans, were understandably proud of playing an important role in the construction of the telescope. They had mounted ahuge American flag on the side of the transport box, primarily out of patriotism, but it had the added benefit that this typically discourages people from shooting, out of respect for the flag and not wanting to damage it. The history of shooting at big boxes goes all the way back to the transportation of the 200 inch mirror to Mt. Palomar by rail in 1936, so mounting the flag had multiple purposes

The drive from Tucson to Mt. Graham takes a couple of hours by car, but when transporting sensitive equipment, one is typically not driving at highway-type speeds. So the transport of the mirrors took more than a day, and the truck spent the night parked at the side of the road. The next day, the transport crew attached a number of fake bullet hole stickers to the transport box, to prank the crew on the telescope construction site. Whether they were fooled or not remains unknown, but one shouldn’t let a good opportunity for a prank be wasted.

One of the LBT mirrors on it’s way to Mt. Graham. Photo credit: University of Arizona LBT project group.

Thanks to John Hill and Tom Herbst for providing details for this story.

On the 5th of February, 1970, a rather bizarre incident happened at the McDonald Observatory, at the 2.7m reflector telescope. A newly hired employee was apparently very dissatisfied with his new job, or, something else was very wrong. Whatever the reason was for said person to be angry with the world, he had decided to take it out on the telescope itself.

Bringing with him a 9mm gun, he first fired a shot at his supervisor, and then fired seven shots, point blank, into the primary mirror of the telescope, no doubt hoping to shatter it. Alas, big chunks of glass like telescope mirrors, do luckily not break so easily, so the bullets merely created small holes in the mirror. Not being happy with this outcome, he also attacked the mirror with a hammer, but to no avail. The mirror did still not shatter. Shortly after, the person was subdued by the rest of the astronomer staff, rushing to the site.

The primary mirror of the 2.7m telescope at McDonald Observatory. The bullet holes can clearly be seen. Photo credit: McDonald Observatory.

When the sheriff arrived, the employee was arrested and later committed to a mental health institution. In the report following the incident, the sheriff, clearly being unfamiliar with telescope designs, stated that the mirror had indeed been destroyed as it had a big, circular hole, right in the middle! Thus, it was allegedly reported widely that the telescope had essentially been destroyed. However, most astronomical telescopes do in fact have holes in the middle of the primary mirror, as it allows you to attach instruments to the bottom of the telescope (the Cassegrain focus). Because of such erroneous stories, the director of the observatory, Dr. Harlan J. Smith, released a report setting the facts straight:

“… The harm suffered by the mirror from his bullets and his several preliminary blows with a hammer was extraordinarily small. The damage is limited to small craters about 3 to 5cm in radius, which reduce the light collecting efficiency by about 1 percent and introduce a very small amount of diffraction …… Astronomical observations of all types are essentially unimpaired by this tragic episode; the telescope resumed its observing program the following night, producing some of the best photographs (of quasar fields) so far obtained with this instrument in its first year of use.”

The full report can be read here.

This is likely the only telescope in the world who has been a victim of a handgun assault, and it will hopefully stay this way. The bullet holes can still clearly be seen in the primary mirror. Fortunately, no people were hurt during this rather tragic incident.

Astro Anecdotes

It's not all about science

No target practice, please

The McDonald gun shooting incident