Why no radio signals from aliens? Is space weather to blame?

The Very Large Array is a collection of 27 radio antennas located near Socorro, New Mexico. Each antenna in the array measures 82 feet (25 m) in diameter and weighs about 507,000 pounds (230 metric tons). These telescopes have been used for SETI, the search for radio signals from aliens. But, so far, no alien signals have been verified. Image via Alex Savello/ NRAO/ SETI Institute.

• Astronomers have searched for alien radio signals for decades. But there are still no confirmed detections.