Astro Hobo

I thought this time I might talk about the places an astrohobo goes to get data. Like so many other parts of so many other jobs, going observing may soon become a thing of the past. More and more telescopes have professional operators who do the real observing while the astronomer sits at home waiting to be notified the data is available. Many other telescopes that do have the astronomer take part in the observing can be operated remotely. The astronomer can sit in front of a laptop in some cafe in Budapest while running a telescope in Puerto Rico. However, alot of the smaller optical telescopes (where smaller means under about 4 meters) still are operated by the astronomer. Which means you get to go to the mountain top, under the stars shining brilliantly in the dark night, breathe the clean alpine air, inspiring you to envision great and powerful ideas.....

Or so you would like to believe. The best optical telescopes are on very high mountaintops. Up at 14,000 feet, like on Mauna Kea, there just isn't much of that cool, clean air to breathe. Which means you are likely suffering from altitude sickness, and your brain is starved of oxygen. So you hope nothing goes wrong, because you are in no shape to deal with it. And even if the instruments are all working properly, you always have to worry about the weather. Clouds. Rain. Wind. Lightning....or just plain turbulent air currents. What astronomers call "seeing". Sometimes it' s good, sometimes it's bad. Tough luck if it is you on the mountaintop, gasping for breath, on your one or two nights on that big telescope, and the seeing just sucks.

I went for a few days to Kitt Peak recently. Lots of small to medium size telescopes there. Very dramatic setting, about 45 minutes from Tucson. Easy for tourists to get to. They have a nice visitor center and guided tours during the day. But it is too close to Tuscon. The lights of the city means it is no longer a really dark site. However, that is the least of your problems in Summer.

Summer is monsoon season. So, almost any night, a very dramatic thunderstorm is likely to pass right overhead. If it does, you have to shutdown the telescope and the computers. Why the computers? Well, besides the possibility of lightning striking the building, it is very likely there will be a brief power outage. The back-up generator will then kick in, but all the power surges going on aren't good for many of those ancient computers that are running various parts of your telescope. So, you get to sit there and watch the pretty lightning until two in the morning, when you try to restart all the computers and hope everything comes up ok. Then you anxiously wait to see if the clouds clear enough for you to squeeze in an hour of observations right before dawn.

This is one reason why I don't do much optical observing. Radio telescopes aren't so picky about the weather and don't need to be so high up in the mountains. In fact, the main thing you need to worry about with radio telescopes are pesky humans. You see, cosmic radio signals are very, very weak. That's why you need telescopes 25, 64, or 100+ meters across. Which means any television transmitter, airport radar, cell phone, faulty spark plug, microwave oven, or just about any other electronic device that isn't very carefully shielded is a huge signal that completely swamps the one you are looking for. So what you try to do is put your telescope somewhere where there is a nice mountain range between it and any decent sized town. Which means the astronomer gets to go somewhere nice and isolated with colorful locals. For example, the Parkes telescope in the western plains of Australia is about a 5 or 6 hour drive from Sydney, on the other side of the Blue Mountains. The Australians have this policy that the astronomer has to operate the telescope. Since it is a long way from anywhere, various astronomers get together and take turns doing each other's observations. So an observing run is likely to last a week or two.

You do not want to get too near a radio astronomer that's been there more than a week. Something about being in the base of the telescope tower every day for about 12 hours with only one or two other astronomers around after normal work hours seems to lead to a lack of personal care. Unshaven, often unshowered, staring out the grilled window at the tourists in the visitor's center staring up at the telescope, or maybe at the rather large spiders hanging just outside the pane. Perhaps you see a few grey kangaroos hopping around. Maybe you are observing with somebody from England who is watching an indecipherable cricket match on the small television in the control room. Or with a Canadian grad student playing the same indie CD on the stereo over and over and over...

And then, excitement. The wind starts kicking up, getting to the point where the dish will automatically go vertical (if it is sideways, it acts essentially like a big sail). And then you need to decide if you are going to lock down the telescope, which involves climbing up to the track where the wheels of the telescope allow it to turn. In the darkness with the wind howling, the occasional spider blowing by, you jack the telescope up and put on the brakes.

Fortunately, outside of Australia, just about every other radio telescope can be run remotely. But you might end up staying for a while in Greenbank, West Virginia or Socorro, New Mexico. Possibly just to plug in disks to lug your data back home in. There are operators who are responsible for the care of the telescope who will keep you from running it into the ground or make the decision that the winds are too high. Much more civilized. At Greenbank, the control room is just a room in an office building. True, there are these heavy metal doors with copper shielding making up the doorstep, and there is mesh over the windows looking out towards the telescope. But at night, you can only see a few distant red lights on the top of the 100+ meter telescope. So, you occasionally look at your computer screens to make sure the thing is pointed in generally the right direction, make sure the data disks are being filled up at the normal, incredible rate of 25 megabytes a second, and otherwise pretend to get some work done in between trips to the coffee machine down the hall.

I bet you never imagined that making astronomical observations could be so exciting!