Signals from an Earth-sized planet detected

Earth’s magnetic field does more than make everyone’s compass needles point in the same direction. This field helps maintain Earth’s atmosphere by deflecting the high-energy particles and plasma that regularly ejects from the Sun. Researchers have now identified an Earth-sized planet in another solar system that is a candidate to have a magnetic field: YZ Ceti b, a rocky planet orbiting a star about 12 light-years from Earth.

Signal from another planet

Researchers Sebastian Pineda and Jackie Villadsen observed a repeating radio signal emanating from the star AI Ceti using the Karl G. Jansky Very Large Array, a radio telescope operated by the US National Science Foundation’s National Radio Astronomy Observatory. A potentially habitable or life-bearing planet needs to be in a similar structure to Earth, at the appropriate distance from its star. However, one of the most important factors is whether it has a magnetic field or not. Because whether a planet’s atmosphere will survive depends on whether the planet has a strong magnetic field.

“Something No One Has Seen Before”

“I’m seeing something that no one has seen before,” says Jackie Villadsen of Bucknell University when he first detected the rado signal while examining the data. The researchers theorized that the stellar radio waves they detected were caused by interactions between the exoplanet’s magnetic field and the star it orbits. However, such radio waves have to be very powerful to be detected at long distances.

The small red dwarf star YZ Ceti and its known exoplanet YZ Ceti b formed an ideal pair because the exoplanet is so close to the star that it completes a full orbit in just two days. (For comparison, the shortest planetary orbit in our Solar system is Mercury’s orbit at 88 days). The interaction between these two is so strong that radio waves can be observed even from Earth. Researchers have not been able to determine whether AI Ceti b has an atmosphere, but future observations will shed light on this. If the planet has an atmosphere, auroras are likely to form, just like on Earth.