Monday, August 20, 2012

VLBA Tour: With Pictures Edition!

As mentioned in my last post, Tuesday I had the opportunity to take a tour of the Very Long Baseline Array (VLBA) radio telescope located on Mauna Kea. It was a great experience, very interesting, and I definitely learned a lot. I brought my camera with me intending to take lots of pictures, only to realize after taking one that my camera battery was drained.

So, I switched over to using the camera in my cell phone, which is where all of these pictures come from.

The VLBA, as I mentioned previously, is the world's largest interferometer, meaning that the 10 radio telescopes in it all work together to give the sharpest views of any telescope ever. In a single night of observing each telescope can accumulate over 15 terabytes of data – so much data, in fact, that it's cheaper to send the physical hard drive to the headquarters in New Mexico by Fedex than to send it over the Internet. This interferometer is so sensitive that they can actually use it to measure how fast continental plates are drifting apart over time, and GPS satellites are kept updated using the information it provides.

Anyway, here's a shot of the Mauna Kea telescope, with some people in the foreground for scale. Each dish is 25 meters across (82 feet), and the whole array is about ten stories high when pointed straight up as in this picture.

The Mauna Kea node of the VLBA.
See that part at the bottom of the dish? That's a room. A room that we got to visit. A small cylindrical room that immediately brought to mind spaceships from every B-grade science fiction movie in the last century.

The room just beneath the center of the radio dish.
The guy in the middle facing the camera was our guide Tony, one of the two employees of this telescope that do the majority of the maintenance.

After that, we climbed up the ladder in the picture to another smaller room where all the instruments were kept. From there, we were able to exit a small door and find ourselves on the mirror itself!

The dish, with the door we came out of visible at the bottom.
Standing on the dish was amazing. Absolutely incredible. As mentioned it's over 80 feet across, all curving in a gently parabolic arc, and so blindingly white I was wishing I had my sunglasses. (The picture doesn't convey it very well, but wow, the white paint on the dish reflected so much light it was like a minor form of snow blindness until my eyes adjusted.)

We were even allowed to climb up the steeply sloping outer edge to where we could look back down to the parking lot almost ten stories below. It was intense. Taking the picture below was difficult, as I was trying to hold on to the dish edge with one hand so as not to slide back down while taking a picture with the other on a phone without a dedicated camera button.

Don't look down!

Pretty amazing view, no? Here's another panorama of the dish taken from the same location by turning around:

As mentioned earlier, the thing in the center that looks like a space capsule is the instrument room where the various detectors are stored. There are quite a few different receivers covering a much, much thicker band of the electromagnetic spectrum than the visible light we can see, and the brown object near the top of the picture is actually a parabolic ellipsoid mirror that can direct the radio waves the telescope receives into any of the various instruments.

It also looks pretty neat with a bit of lens flair behind it.
So, there you have it. Pictures from my VLBA tour. All in all it was a great experience, the two guys who run it were great to talk to, happy to show off and talk about their telescope. You could tell they loved what they did. Anyway, that's it for tonight, a hui hou!

P.S. This telescope is located at about 11,000 feet on Mauna Kea, nearly 3,000 feet below the summit, so none of the hills you see in these pictures is the summit peak. Just local cinder cones.


  1. Thanks! I wouldn't have been able to do this if I had had my old cell phone, that's for sure.


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