As the search for another lifeform beyond Earth continues, an alien signal has been beamed to the planet from Mars for the first time. The European Space Agency’s ExoMars Trace Gas Orbiter (TGO) flashed an encoded message to Earth from its orbit around Mars on Wednesday at 9:00 PM to simulate a situation when we receive an actual signal from another civilization. The radio waves hit Earth 16 minutes later.
Since SETI got underway in 1960, the methods used by astronomers to find aliens have evolved dramatically. In addition to listening for radio signals, researchers now look for lasers and other visual signs of possible alien life. But the primary criterion that must be met for a potential signal to qualify as evidence of aliens remains the same: a repeating one. This is because intelligent beings if they were trying to communicate with us, wouldn’t broadcast just one signal. Instead, they’d send repeated ones on a regular schedule to ensure that the message is heard.
But a new study shows that we’re still not very good at finding these signals even with our advanced technology. The research, published in the journal Nature Astronomy, reports that a star called YZ Ceti and the rocky planet that orbits it appear to be sending repeated radio signals. In a series of tests, astronomers discovered that the planet’s magnetic field appears to alter how the star’s radio waves are emitted. The result is a signal that’s much more powerful and longer lasting than the natural radio signals emitted by the star.
The researchers have been experimenting with the Karl G. Jansky Very Large Array of Telescopes in New Mexico. They’ve observed two coherent radio bursts from YZ Ceti and its planet, which appear to be generated by magnetic fields that the star’s atmosphere exerts on the planet. They think that if the planet’s magnetic field were to weaken, the star’s radio emissions would become more uniform and less powerful.
These findings are a promising step toward the search for aliens. But it’s essential to remember that it’s unlikely that these specific radio waves are the results of intentional alien communication, said Kaitlin Rasmussen, an astrobiologist at the University of Washington not involved with the study. For an intentional alien radio signal to be detected, it must be relatively robust and long-lasting. However, the signal sent by YZ Ceti b was only powerful and short enough to be detected in one of the five 30-minute observations made over three hours.
But an institute searching for aliens hopes to improve our odds of decoding a possible signal by inviting the public to participate in what they’re calling a Solar System-wide ‘fire drill’ this week. Daniela de Paulis, an artist in residence at the Search for Extraterrestrial Intelligence Institute, has created a project called A Sign in Space that will see an encoded message beamed by the European probe to the Green Bank Telescope in West Virginia, the Medicina radio astronomy station in Italy and the Allen Telescope Array in California. The teams at each observatory will then attempt to decode the signal and determine its cultural content.
