No, this won’t be about Google Sky or Google Mars or anything like that. This is just plain old Google Maps. I was dismayed to find that a topology map website I had used before now required your credit card information to view, but I still needed some view of our telescope site to plan one of my experiments. Our little proto-type array, called PAPER, or the Precision Array to Probe the Epoch of Reionization, is situated in Green Bank, WV, also the site of one of the largest single-dish radio telescopes in the world. Last time I had checked, most of Green Bank was a fuzzy green blob. But now, the images have been updated!
First, a clear look at the Green Bank Telescope from above:
You can see the support buildings around it, and the little mounds where the laser surface system was being designed, and the huge shadow that it casts, showing its profile. Wow.
This doesn’t look like much to most, so here’s the brief tour. At the upper left of the image is a white circle, and that antenna is known as 85-2, or the second 85-ft antenna that was used in early interferometry experiments. Coming from that is a dirt “road” to the center of the field, and that ends at our electronics hut. It houses the receivers, power supplies, computers, and a special computer for interferometry, called a correlator. The hut is in the center of an imaginary circle, and on that circle is where we place our antennas. These antennas are 5ft x 5ft wire mesh screens, painted white, with white wire mesh flaps on each end at a 45-degree angle, and a metal sleeved dipole in the middle. They are cute little things, really, and I was shocked to see them in this satellite image.
Only two were in the field at the time this was taken (late 2007) and you can see them at the 12 o’clock and 3 o’clock positions on the circle.* PAPER can be seen from space! Right now, we have 16 of these antennas on that circle, monitoring the sky round the clock, and giving us a wealth of new data that we can use to image the sky at low frequencies and test our imaging algorithms. One of these days I will have to really write about PAPER, or you can wait for the April 2nd installment of the 365 Days of Astronomy Podcast!
After showing this to my labmates, we scooted over to one of our other favorite radio telescopes, the Very Large Array. Zoomed out, you can see the tracks that make up the arms of the interferometer that extend out to 13km. But zoomed into the center of the array:
You can see pretty fine details, even the arms of the subreflectors above the dishes! Wow.
So go ahead, type in your favorite telescope and see if Google Maps has some cool views.