Radio antennas at the Canberra facility of the Deep Space Network in Australia
NASA/Canberra Deep Space Communications Facility
If aliens are nearby and listening to spacecraft command signals, we may hear back from them as early as 2029.
Since 1972, NASA has used a system of radio antennas called the Deep Space Network (DSN) to track spacecraft and send powerful radio signals to them.
Howard Isaacson of the University of California, Berkeley, and Riley Derrick of the University of California, Los Angeles, determined which stars these radio signals reached and when…
