Ever since Jodi Foster starred in the movie “Contact” I have wanted to see the radio telescopes in person. The observatory was only a few miles off the road so we decided to go for it. The site consists of 27 independent radio antennae, each of which has a dish diameter of 25 meters (82 feet).
The antennas are arrayed along the three arms of a Y-shape (each of which measures 21 km/13 miles long). Using the railroad tracks that follow each of these arms – and that, at one point, intersect with U.S. Route 60 at a level crossing – and a specially designed lifting locomotive, the antennas can be physically relocated to a number of prepared positions.
There are four commonly used configurations, designated A (the largest) through D (the tightest, when all the dishes are within 600 m of the center point). The observatory normally cycles through all the various possible configurations (including several hybrids) every 16 months: in other words, once the massive efforts needed to move two dozen 230-ton highly sensitive scientific instruments have been made, the antennas are not moved again for a period of three to four months.
The movie was filmed when the dishes were in the tightest configuration. When we saw them, they were spread out over the 13 miles.
Oh Jodie, you are quite the dish.