One of the many methods that scientists have been using in the search for life on other planets is via the radio—or rather, incredibly powerful and precise radio antennas pointed at the cosmos. While this has occasionally yielded some promising results—for example, the famous ”Wow!” signal detected in 1977—much of the search has gone pretty much nowhere.
Luckily, there’s some new hope: In a study published Monday in the journal Nature Astronomy, scientists discovered a repeating radio signal from an Earth-sized exoplanet called YZ Ceti b, roughly 12 light-years from our solar system. While it’s unlikely that it’s ET firing off radio signals in the hopes that we pick up on it, the study’s authors suggest it could mean that the planet has its own magnetic field—which is a crucial component for how the Earth hosts life.
Unfortunately, the chances for finding life on YZ Ceti b are incredibly low. The planet orbits its host star every two days, which means it’s sitting way too close to the star for anything to survive the high amounts of heat and stellar radiation. However, it still provides astronomers a great opportunity to study star-planet interactions, or all of the ways that stars impact their planets and vice versa. Using this information, scientists can zero in on other planets that might have life on them. The study’s authors write that YZ Ceti b specifically creates a “uniquely promising case study for magnetic SPIs.”
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To reach their findings, the study’s authors used data gathered by the National Science Foundation’s Very Large Array (VLA) in New Mexico. They discovered “the detection of 2-4 GHz coherent radio bursts” from the host star YZ Ceti, including one burst in a two-day period. Using this information, they surmise that the exoplanet YZ Ceti b could be the source of the signal.
"Whether a planet survives with an atmosphere or not can depend on whether the planet has a strong magnetic field or not,” Sebastian Pineda, a research scientist at the Lab for Atmospheric and Space Physics at The University of Colorado, Boulder and co-author of the study, said in a statement. "We saw the initial burst and it looked beautiful. When we saw it again, it was very indicative that, okay, maybe we really have something here."
Pineda and his co-author Jacqueline Villadsen, an assistant professor of physics and astronomy at Bucknell University, zeroed in on “short-period” planets, or planets with fast orbits, zooming around YZ Ceti. The idea is that because they’re so close to the host star, their magnetic fields have a likelier chance of interacting with the host star’s—and create radio bursts as a result.
While YZ Ceti b itself is unlikely to host life, the findings do provide scientists a new method of detecting potential candidate planets for our search for aliens. Eventually, researchers will be able to hone in on the type of signals we can expect from an Earth-like exoplanet. However, the authors do add that more research is needed to verify whether or not this is an actual case of magnetic SPIs.
"The search for potentially habitable or life-bearing worlds in other solar systems depends in part on being able to determine if rocky, Earth-like exoplanets actually have magnetic fields," Joe Pesce, the program director for the National Radio Astronomy Observatory who wasn’t involved in the study, said in a statement. "This research shows not only that this particular rocky exoplanet likely has a magnetic field but provides a promising method to find more."
