Earth Signals Best Detected When Earth Aligns With Mars, Study Finds

A new analysis of humanity’s deep-space transmissions suggests that signals from Earth would be most detectable to extraterrestrial observers when certain planetary alignments occur. By studying two decades of NASA’s Deep Space Network transmissions and the positions of interplanetary spacecraft, researchers say that alien observers could have an easier time hearing Earth when our planet aligns with Mars, or with other planets and key solar-system positions. The findings also offer a concrete, testable direction for our own search for alien technosignatures.

The study examined how our strongest interplanetary communications—largely those directed at spacecraft, telescopes at sun-Earth Lagrange points, and other deep-space targets—align with the movements of planets in our solar system. By pairing Deep Space Network logs with spacecraft locations, the researchers mapped when and where Earth’s radio signals travel into space. They emphasize that the Deep Space Network serves as a representative conduit for these transmissions, given NASA’s lead role in most deep-space missions and the network’s long-running logs of two decades of activity.

Findings show a clear pattern: deep-space...