Overview

• The peer-reviewed analysis of roughly 20 years of DSN transmissions finds Earth’s strongest deep-space signals are tightly directed at probes—especially near Mars—and lie within about 5 degrees of the ecliptic.
• Modeling shows an external observer viewing an Earth–Mars alignment had a 77% chance of crossing a DSN beam path, versus about 12% for alignments with other planets and negligible odds otherwise.
• The team estimates typical DSN spillover could be detected with telescopes like ours from roughly 23 light-years away, setting a practical search radius for similar alien networks.
• The authors urge SETI programs to prioritize edge-on, transiting exoplanet systems and to schedule observations during planetary conjunctions or planet–planet occultations, and they are now identifying nearby candidates and observation windows.
• The work, published in The Astrophysical Journal Letters and presented at the Penn State SETI Symposium, notes a prior TRAPPIST-1 alignment search returned a null result and that laser communications would leak far less than radio.