No-touch telescopes

Ken Tapping, October 15th, 2014

In the sky this week…

  • Jupiter rises in the early hours.
  • Saturn lies low in the sunset glow, Mars is lower and hard to find.
  • The Moon reaches Last Quarter on the 15th.

A few years ago I had a chance to visit Percival Lowell’s old observatory at Flagstaff, Arizona. This was the instrument Lowell built to study Mars. His intention was to map what he believed were the waterways built by Martians to manage the waning water supply on their dying world. I even got to look at the night sky through the instrument.

There is a vision of what astronomers do that is still very much with us. The experience with Lowell’s telescope was just like that. The dome was dark, with assorted faint indicator lights, and a slice of starry sky showing through the opening in the observatory dome. It was quiet except for humming and ticking from the equipment. Lowell would have sat in that dark dome for hours, patiently looking through the telescope. Although we still cling to images like that, making astronomical observations today is very different.

Once upon a time there was great similarity between telescopes and instruments at different observatories, so that with a little help before starting the observations, a visiting astronomer could drive the equipment and acquire data, armed only with a phone number to call if problems arose. By the 1970’s telescopes and the instruments used on them had become more complex. Observations were made with the help from a telescope operator or observing assistant. Then, as telescope control computers became more sophisticated, the astronomer could work with the computer, which would not let him do anything silly to the expensive equipment. The telescope operator sat nearby reading magazines, but was present, just in case. Soon after we were putting our entire observing session into a single computer file. The telescope could then do hours of observations with no human input at all. On one side this could make an overnight session stunningly boring. However, it also avoided the stupid things we do so easily between 2 and 4am.

Today, the instruments are so expensive and so complex we only trust them to trained operators. Moreover, with the high-speed Internet connections, for the usual experiments there is not much need for astronomers to be on-site at all. This is actually good for two reasons. Firstly it saves a lot of money that would have been spent on travel and accommodation, and secondly it means the observatory can operate to a more flexible schedule. This is a great advantage.

Until recently observations were carefully scheduled for fixed dates and times. You would be informed precisely when the telescope would be available for you to use. You would then contact the airlines, hotels and rental car companies as needed for your observing trip. Unfortunately there was no guarantee that at your scheduled times the observing conditions would be suitable, and there was always a chance a critical piece of equipment could fail. With luck you could avoid a wasted trip by having an alternative project or two in your back pocket, but still you would not be doing what you had come hundreds or thousands of kilometres to do. This wasted your time and highly expensive telescope operating time too.

Today, since for most projects there is no need to be at the observatory, there is no need for such rigid scheduling. The staff can adjust the schedule to fit the observing conditions and to accommodate equipment failures. Since you are staying at home this is no problem. You just wait for a message saying your observations have been made and the data is ready to download. For ground-based observatories this way of operating is convenient, but for space-based instruments and observatories on the surface of the Moon, this will probably be the only way to observe, although an observing trip to one of those instruments would be fun.

Ken Tapping is an astronomer with the National Research Council's Dominion Radio Astrophysical Observatory, Penticton, BC, V2A 6J9.

Telephone: 250-497-2300
Fax: 250-497-2355

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