Very Large Array

US-60 west of Magdalena climbs onto the Plains of San Agustin, the floor of an Ice Age lake, and the dishes appear miles ahead, white against the grass. The Very Large Array has twenty-seven working antennas and a spare, each dish 82 feet across and weighing about 230 tons, set along three arms of track in a Y, each arm about thirteen miles long.

The antennas work as one instrument. Their signals are combined to give the sharpness of a single dish many miles wide, aimed at radio waves from galaxies, black holes and the gas between stars. Every few months a transporter lifts the antennas one by one and carries them along the rails into a new arrangement, gathered close to the center for a wide view or strung out to the ends of the arms for the finest detail.

Congress authorized the array in 1972 and it was built through the 1970s, dedicated in 1980. In 2012, after new electronics multiplied what it could do, it was renamed the Karl G. Jansky Very Large Array, for the Bell Labs engineer who first detected radio waves from space in the early 1930s. The 1997 film Contact put it in front of millions of people who had never heard of radio astronomy.

The visitor center has a small museum and a short film narrated by Jodie Foster. A self-guided walk of about half a mile passes a radio sundial and ends at the base of one of the working antennas.