telescope

No target practice, please

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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.

LBT-moving-mirror-28oct3

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.

Shooting for the stars

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Just like any other field of science, astronomy has had its share of colorful characters over the years. One of the more recent ones was no doubt Fritz Zwicky (1898-1947). Zwicky was a Swiss astronomer, who came to California Institute of Technology as a graduate student, and ended up as a full professor, spending the rest of his life in Pasadena.

Zwicky was known for his antics and sometimes odd behaviour, both during social gatherings, but also during scientific work. In terms of the latter, one could probably consider him thinking very far outside the box. One of the more famous episodes happened during a night of observing with the 200″ Hale telescope at Mt. Palomar Observatory;

One of the challenges when observing objects close to the Earth, is the ability for the telescopes to track fast-moving objects. You want your telescope to be able to move fast across the sky. At the same time, it needs to move smoothly enough so that the object you are tracking stays on the same spot on your detector. This is far from trivial, and even with modern telescopes, accurate tracking of near Earth objects can be quite challenging.

In the days of Fritz Zwicky this was even more true than today. And understandably it was of interest to determine just how fast and accurate it was possible to track objects with the Hale Telescope. Zwicky took an somewhat unconventional approach to testing this.

The 200-inch Hale Telescope at Palomar Observatory

The 200″ Hale Telescope. Photo credit: Palomar/Caltech.

Together with his night assistant, Ben Traxler, he conducted an experiment, where several shots were fired with a rifle out through the dome slit. Zwicky would then attempt to track the bullets with the Hale Telescope. There are no reports as to how successful this experiment was, but  it is definitely an example of Zwicky’s outside-the-box thinking. The incident did however, result in Zwicky being temporarily banned from using the Hale telescope.

On the other hand, his way of thinking did lead to groundbreaking research in supernovae amongst other things. He also proposed several ideas that were subsequently confirmed, like neutron stars, gravitational lensing and dark matter, many of which were not taken seriously at the time.

To my knowledge, Zwicky has been the only astronomer who was literally “shooting for the stars”. Which should probably be considered a good thing.

Thanks to Barbarina Zwicky for providing details for this story.

The McDonald gun shooting incident

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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.

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.

The telescope that ran over a car

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It is well known that cars are often involved in accidents, either by crashing into something, running over things, slipping off the roads and similar nasty business. This is also true in astronomy, where accidents do happen from time to time. What is different though, is that while cars can run into things almost everywhere, having something running over your car is a much rarer experience.

The Nordic Optical Telescope. Photo credit: NOT, Thomas Mellergaard Amby.

The Nordic Optical Telescope. Photo credit: NOT, Thomas Mellergaard Amby.

Meet the Nordic Optical Telescope (NOT): A nice, 2.5m telescope of a somewhat peculiar design. Whereas all telescopes have some sort of turning dome, that allows the telescope to point to many different parts of the sky, the NOT is constructed in such a way that not only the dome, but the entire telescope building turns, when you want to aim your telescope at a different patch of sky. This of course involved some engineering challenges, like, plumbing (there’s no bathroom in the telescope), as well as an entry staircase that is attached to the telescope. Which, amongst other things, means that you never really know what direction you are facing when you leave the telescope.

One day, the day-time crew were in need of hoisting equipment into the telescope dome, from the observatory pickup. For the crane to be able to reach the equipment, it needs to be positioned right at the wall of the telescope building. Thus, the pick-up was backed up, really close to the telescope, to make it easier to get the equipment in. This being an everyday operation, the crew unloaded the pickup, closed the dome, and proceeded with whatever they were doing.

The one warning sign you do want to pay attention to.

The one warning sign you do want to pay attention to.

Shortly after, someone decided that the telescope should be put in the parking position, so it was ready for the night to come. A sensible thing to do, except that no one had checked if the pickup had been moved away from the building. Thus, as the building turned, the entry staircase rammed into the side of the pickup, with the telescope effectively running over the car. Fortunately, the impact cut the wires to the safety system, which happened to run along the staircase, forcing the telescope to an emergency stop. Had this not happened, the telescope building could have been severely damaged, and the pickup as well.

The damages were luckily so small that the pickup could drive out of there, and at the time of writing, is still being used at the telescope. This is also one of the times where it really pays off to pay attention to the warning sign outside the telescope building.