A new scientific study has demonstrated that the most promising moments to detect extraterrestrial civilizations are during planetary alignments, when deep space communication systems are most active and their signals are most likely to spill into interstellar space. The findings come from a detailed analysis of NASA’s Deep Space Network, published in The Astrophysical Journal Letters in September 2025, and provide the clearest evidence yet that Earth itself is already broadcasting detectable signals in structured patterns that could be intercepted by other civilizations.

The research team, led by Pinchen Fan of Penn State along with Jason Wright and Joseph Lazio of NASA’s Jet Propulsion Laboratory, examined twenty years of transmission logs from NASA’s global Deep Space Network, which operates powerful radio antennas in California, Spain, and Australia. These facilities are responsible for maintaining communications with spacecraft throughout the solar system. Every command sent to a planetary probe, every stream of data returned from an orbiter, and every routine contact with a telescope beyond Earth’s orbit involves the use of these antennas. Each transmission is aimed at a spacecraft target, but the radio energy continues outward indefinitely into space.

The researchers mapped the pointing directions of the transmissions and recorded how long each region of the sky had been illuminated, calculating the duty cycle for every point. Between January 2005 and January 2025, the antennas covered approximately fifteen percent of the celestial sphere. The analysis revealed that the distribution of signals is far from random. Nearly eighty percent of transmission time was concentrated within five degrees of the ecliptic plane, which is the flat plane defined by Earth’s orbit and shared by the other planets. For any observer located near this plane, Earth would already appear as an active source of radio transmissions.

The duty cycle within the Earth Transit Zone, the narrow strip of sky from which Earth would be seen passing in front of the Sun, was found to be about twenty times higher than the average across all latitudes. This means that a civilization located in that zone would have far greater opportunity to detect Earth’s transmissions than one located elsewhere. The concentration is explained by the fact that most spacecraft are launched and operated close to the ecliptic, so antennas are almost always pointed within a few degrees of this plane.

The strongest concentration was observed along the Earth–Mars line. Because of the continuous presence of orbiters, rovers, and landers at Mars, the Deep Space Network has maintained an exceptionally high level of communication with the planet. The analysis shows that during Earth–Mars conjunctions, when the two planets align, a distant observer situated on that line would have had a seventy-seven percent chance of intercepting a transmission in the past twenty years. This represents an increase in detectability by a factor of four hundred thousand compared to random chance.