Astronomers take a leap in search of Earth-like planets – but what they’re looking for is invisible | Science and technology news
Astronomers searching for Earth-like planets have discovered one in another solar system that appears to have one of the unique criteria for sustaining life – a magnetic field.
You may not often pause to thank Earth’s magnetic field for having you here today, but it is vital to protecting our planet’s life-supporting atmosphere.
It does this by deflecting the high-energy particles and plasma that are regularly shot out of the sun.
Now scientists think they’ve found another Earth-sized planet with a magnetic field — YZ Ceti b, a rocky planet orbiting a star about 12 light-years from Earth.
Because magnetic fields are invisible, it’s difficult to determine if a distant planet actually has one, according to Jackie Villadsen, an astronomer at Bucknell University in the US.
But being able to tell if that’s the case is critical to finding potentially habitable or life-bearing worlds, said Joe Pesce of the National Science Foundation.
“This research not only shows that this particular rocky exoplanet likely has a magnetic field, but also offers a promising way to find more,” he added.
The researchers detected radio waves that they theorized were produced by the interactions between the planet’s magnetic field and the star it orbits.
The research results were published Monday in the journal Nature Astronomy.
A planet’s magnetic field can prevent its atmosphere from being eroded over time by particles ejected from its star, said Sebastian Pineda, an astrophysicist at the University of Colorado.
In other words, a strong magnetic field can mean life or death for a planet’s atmosphere.
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YZ Ceti b isn’t habitable – it’s too close to its star for that, but it has another resemblance to Earth – the Northern Lights.
The Sun’s high-energy particles create the solar weather around the Earth, and the interaction between this and the Earth’s magnetic field and atmosphere creates the phenomenon of the Aurora Borealis, or Northern Lights.
The interactions between YZ Ceti b and its star also produce an aurora – but on the star itself.
However, the scientists said that if the planet has its own atmosphere, there should also be auroras.
Both researchers agreed that YZ Ceti b is the best candidate yet for a rocky exoplanet with a magnetic field, but said it would need “a lot of follow-up work” before this could be confirmed.