According to a recent study published in “Nature Astronomy,” scientists have discovered a mysterious signal that repeats every two days, and what’s intriguing is that it originates from an Earth-like planet located just 12 light-years away from Earth, which is relatively close on the galactic scale.

This Earth-like planet is called “YZ Ceti b,” with a mass approximately 0.7 times that of Earth. It resides in the constellation of Cetus, orbiting a dim red dwarf star named “YZ Ceti.”

“YZ Ceti” is a faint red dwarf star with a mass of about 13% of the Sun’s mass and a radius of approximately 16.8% of the Sun’s. It hosts three Earth-like planets, with “YZ Ceti b” being the closest, and the other two being “YZ Ceti c” (about 1.14 times Earth’s mass) and “YZ Ceti d” (about 1.09 times Earth’s mass).

In this study, scientists found that the source of this mysterious signal highly coincides with the position of “YZ Ceti b,” suggesting that it indeed originates from this Earth-like planet.

This situation naturally raises thoughts of extraterrestrial civilizations since the universe is unimaginably vast, and there’s reason to believe that humanity shouldn’t be alone in the cosmos. It’s reasonable to speculate that, like us, some extraterrestrial civilizations might send radio signals into deep space once they master radio communication technology.

However, when it comes to whether this discovered mysterious signal is genuinely connected to extraterrestrial civilizations, the scientists of this study express that the possibility is very low. The reason is simple: the natural conditions on “YZ Ceti b” are extremely harsh and unsuitable for sustaining life.

Observational data indicates that “YZ Ceti b” orbits very close to its host star, with a semi-major axis of approximately 0.016 astronomical units and an eccentricity of about 0.06.

According to scientists’ estimates, at such a close distance, the surface temperature of “YZ Ceti b” would reach up to 300 degrees Celsius, and if this Earth-like planet had an atmosphere, the surface temperature would further increase due to the insulating effect of the atmosphere.

So the question arises: if this mysterious signal, which repeats every two days, isn’t related to extraterrestrial civilizations, how is it generated?

The explanation provided by the research team is that “YZ Ceti b” likely possesses a strong magnetic field. When it revolves around its host star, its magnetic field interacts with the “stellar wind” released by the host star, resulting in regular radio signals.

In simple terms, “stellar wind” is a high-speed stream of charged particles released from the surface of a star. In fact, our Sun also has a “solar wind.” Researchers believe that since “YZ Ceti b” is very close to its host star, its orbital speed is high, and the material density of the “stellar wind” near its orbit is also high. If “YZ Ceti b” has a strong magnetic field, it would effectively alter the motion of charged particles near its orbit (as charged particles are influenced by magnetic fields). These altered charged particles would then interact frequently and vigorously with other substances in the “stellar wind,” generating strong radio waves.

Because this kind of radio signal can only be detected on Earth when “YZ Ceti b” is in a specific position in its orbit, it appears as a regular mysterious signal. Correspondingly, the orbital period of this Earth-like planet is approximately 2.02 Earth days, which explains why the signal repeats every two days.

Researchers point out that while this explanation seems reasonable overall, it cannot be confirmed yet, as subsequent observational data showed that the signal is not perfectly synchronized with the orbital period of “YZ Ceti b.” Currently, there is no definitive answer for this phenomenon.