Radio emissions from nearby star system could point to Earth-like planet’s magnetic field | CBC News

Scientists have discovered repeating radio emissions coming from a star system in our galactic backyard.

It’s not a message from aliens, but it might show that some Earth-like planets outside the solar system have a magnetic field — one of the conditions necessary for life as we understand it.

Using the Karl G. Jansky Very Large Array in New Mexico, two researchers noticed repeating radio waves coming from a star called YZ Ceti in late 2019 and early 2020.

J. Sebastian Pineda of the University of Colorado, Boulder, and Jackie Villadsen of Bucknell University in Pennsylvania suspect the “coherent” radio bursts occur due to interactions between YZ Ceti and a rocky planet that orbits it, YZ Ceti b.

Magnetic field keeps us safe

They theorize, in a study published Monday in the journal Nature Astronomy, that the Earth-sized exoplanet has a magnetic field that is interacting with the red dwarf star, causing an aurora on the star itself that is being detected on Earth.

The Earth’s magnetic field is a vital shield that protects us from dangerous radiation from the sun and deep space that would otherwise scorch us, remove our planet’s atmosphere and blow our electrical system and electronics to smithereens.

Scientists have previously detected the signature of a magnetic field on an exoplanet, but it was a planet described as Neptune-sized and Jupiter-like. 

“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,” said Joe Pesce, the U.S. National Science Foundation’s program director for the National Radio Astronomy Observatory. The observatory operates the Very Large Array.

“This research shows not only that this particular rocky exoplanet likely has a magnetic field, but provides a promising method to find more,” he said in a statement.

The YZ Ceti star system is very close to Earth, only about 12 light-years away, which in space terms makes it a next-door neighbour. (Other similarly nearby stars include Wolf 359 and Alpha Centauri, two locations that are meant to seem “right next door” on the sci-fi franchise Star Trek.)

Star system has ‘unique promise’

YZ Ceti is not visible to the naked eye, but is in the constellation Cetus, which most Canadians can find in the sky in the fall and winter.

Though a rocky, magnetic-field-covered world in our neck of the woods might sound like a promising place for discovering life, YZ Ceti b is way too close to its star, in an orbit it completes in just two days. 

That makes it a great study subject, though, with the planet moving through matter emanating from the star. YZ Ceti has “unique promise as a target for long-term monitoring,” the researchers say in the study.

“We’re looking for planets that are really close to their stars and are a similar size to Earth,” Villadsen told the National Science Foundation. “These planets are way too close to their stars to be somewhere you could live, but because they are so close, the planet is kind of plowing through a bunch of stuff coming off the star.

“If the planet has a magnetic field and it plows through enough star stuff, it will cause the star to emit bright radio waves.”

The study authors say it will take more research to determine if their theory is correct, and not simply the normal activity of the star.

“This could really plausibly be it,” Villadsen said. “But I think it’s going to be a lot of follow-up work before a really strong confirmation of radio waves caused by a planet comes out.”