Astro Hobo

There I was, planning a non-astronomy related trip to Puerto Rico, and thinking "I gotta see the biggest telescope in the world before it gets shut down". So, like any astrotype, I do what I have to do to get them to be nice to me.

I offer to give a talk.

Good thing too, because the visitor center is closed on tuesdays, and the random public isn't allowed in past the gate. While in the rest of the world an astronomer is just a poorly dressed schlub, at a telescope astronomers are Very Important People. It's actually quite odd. See an astronomer in their tiny, cluttered office or at a bar in a conference hotel complaining about the cost of a beer, and they can easily be dismissed as an inconsequential nobody. And, to be honest, as you are working away, you often feel that nobody pays attention to what you do anyway. Not even other astronomers.

But then you go to a major telescope, and suddenly there is this dramatic, giant instrument which cost maybe $100,000,000 and has a full time staff of 50, 100 or more people monitoring it, repairing it, upgrading it, archiving the data it takes, maintaining all these computers, offices, even visitor quarters. And for an evening, or a day, or even a few days, all that staff and equipment is working to get YOU data for YOUR idea. Makes you feel those 5-9 years of graduate school really did make you into something special and were worth all the hard work and suffering.

Almost.

Anyway, there I was in Puerto Rico driving up windy mountain roads and see in the distance poking up over a hill a 365 foot tower. This is one of three supporting the massive platform where the receivers are mounted 450 feet above the surface of the giant 1000 foot (thats 305 meters) radio dish that is the Arecibo Observatory telescope. You know, the one you saw in the movie Contact or in Goldeneye. And, if you are wondering if the telescope really does look for extraterrestrials, the answer is yes. All the time. As part of the Search for Extraterrestrial Intelligence, there is a special bit of equipment known as SERENDIP
This rack of electronics siphons off a bit of the signal from the telescope wherever it happens to be looking and sends it off to search for signs of other civilizations. So, not only might you discover what you are looking for when you observe, there's always the chance you will discover aliens. There is a similar set up at the Parkes telescope in Australia.

So, I drive up to the gate and tell the guard I am there to give a talk. They call in, give me a sticker to put on my shirt which I immediately lose, then tell me how to get to the observatory control buildings. There I meet Chris Salter, who had been a bit of an Astrohobo himself before settling down at Arecibo. He has all sorts of great stories about the observatory. Since there is a bit of time before my talk, we hike up to the edge of the dish to look it over.

Now I've known about Arecibo for a long time, and have even used it remotely before. I knew it was built into this big valley, with this monstrous track hanging above it on which moves around the receiver allowing you to point to the part of the sky you want to study. Somehow, though, it never occurred to me that the dish itself was suspended above the surface of the valley, and underneath is a unique ecosystem. The surface of the dish is metal mesh, so rain and partially blocked sunlight flow through it. This makes it very similar to a rainforest, except the dish is playing the role of the trees. At the bottom of the valley is a sinkhole that drains the rain down to a huge underground river that you can see in a set of nearby caves (I didn't make it there, so I can't tell you much more about them).

Although the Arecibo observatory has made a slew of cool discoveries as a radio telescope, perhaps the coolest things it does is when it becomes the world's most powerful radar dish. Giant radio signals have been sent out from it and bounced off of all sorts of things in our solar system. The tiny bit of the signal that is reflected off of, say a nearby killer asteroid (ok, maybe not a killer asteroid, but many near earth objects, some of which could be killer asteroids) and makes it back to Earth is then detected by the dish. One of the most recent radar discoveries made using the Arecibo radar (in combination with the 100 meter Greenbank Telescope and NASA/JPL antennas in Goldstone CA) is that Mercury has a molten core.

Well, eventually I had to give my talk allowing a bunch of tired researchers to take an afternoon nap. Then I even got sort of paid: I was given a nice mug which is all black when empty but shows a picture of the observatory when something hot is put in it. Well worth the effort. So, before it gets shut down so the operating funds can be shifted to support ALMA
go take a vacation to Puerto Rico and spend a day visiting the telescope and the nearby caves. And then go down to the shore and jump in the ocean. Because it is a tropical island, after all, and there are other reasons to go to Puerto Rico...or so I hear....

So, mid-term elections are in a few days. I'm in Europe at the moment, but I voted before I left. A nice, paper absentee ballot where I marked my vote with a pen, so it can be counted.

What about you? Are you going to vote this disastrous group of Republicans out of
office?

"Wait a minute!" some of you might be thinking. "Isn't this a blog about Astronomy?"

You betcha. And guess what? All those lovely telescopes take lots of money and years of commitment by the U.S. government to be built and operated. It can take 15, 20, or even 30 years for a major Nasa mission, such as the Chandra X-ray, Spitzer infrared, or GLAST gamma-ray observatories to be developed, built and flown. In fact, because of the foresight of scientists and politicians from previous decades, going back to the late 60s, we are in the golden age of space-based astronomy.

Which is coming to an end. Simply put, nearly all funding for developing the next generation of astronomy missions has been stopped. So no one really can say what or when will be the next generation of space-based astronomy. Funding throughout the government is being shifted away from scientific research for boondoggles like the Mission to Mars. Things politicians with no respect for science dream up. Basically, the Republican majority is anti-science. That is why, despite the rapid melting of glaciers and the perma-defrost, the increase in global temperatures and hurricanes, instruments to study global warming are sitting in storehouses with no plans to be launched.

So, even if you can't think of any other reason to go and vote the Republicans out of office, do it for science.

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!