Science is slow going. Sure, eveyone loves the big headline-grabbing discovery. What really makes science powerful and worth defending, however, is how… um… boring it is. So many hours of painful, exacting work requiring a thousand people to make one tiny step forward.

But that’s why you can trust it. All that effort eventually pays off.

That’s exactly what happened last week when astronomers announced they’d finally detected a magnetic field surrounding an alien planet. This has been a holy grail in exoplanet science for decades. The first exoplanet was discovered more than 30 years ago but since then all attempts at finding exoplanet magnetic fields yielded bupkis.

So the first question … who cares?

Magnetism is an invisible force field generated by swirling electrical currents. A bunch of planets in our solar system generate their own magnetic fields via electrically charged stuff circulating deep in their planetary interiors. Earth is one of those magnetic-field-makers and it turns out your life likely depends on that field.

Earth’s field forms a kind of interplanetary shield protecting the planet from powerful, harmful radiation streaming from the Sun. Without that magnetic field, it’s possible that life would never have had the chance to evolve in the way it did (too many solar particle induced too many mutations). It’s also possible that the field protected our world’s atmosphere from being slowly stripped away by those solar particles. Mars doesn’t have much of a magnetic field and some scientists believe that’s why it doesn’t have much of an atmosphere too.

So, that’s why magnetic fields matter. We believe there may be a strong link between a planet having a magnetic field and the ability of that world to be habitable for life. So the question then becomes do exoplanets have magnetic fields? Until recently, the answer was “we just don’t know”.

Last week, however, astronomers reported finding radio emission from an aurora occurring in the upper atmosphere of the planet Beta Pictorus b (i.e. Beta Pic b). Aurora happen when charged particles from the host star flow into a planet’s magnetic field and emit radio waves.

Beta Pic b is a much bigger planet than the Earth. That translated into a much bigger magnetic field, a much bigger aurora and much louder radio emission. The gigantism is why astronomers could make the detection.

Finding magnetic fields on Earth-like planets (where we think life could exist) will be much harder though becuase the fields will be much weaker. That’s OK. Now that we know it’s possible to make these magnetic detections we’ve crossed the rubicon. Eventually we’ll figure out how to catch the one’s for smaller Earth-like planets - the kind where life might form.

Becuase magnetic fields may be so important for life, finding a planet with a field and a potential biosignature would - together - offer a much stronger case for an active eco-biosphere.

That’s why this discovery is such a big deal.

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PS If you have specific questions or issues you want me to address leave a comment on the website or email me at [email protected]

PPS I could not get this proof-read so please excuse typos etc.

— Adam Frank 🚀