Clipmark

This artist's concept shows a gas giant planet orbiting the cool red dwarf star Gliese 876 (Image: G Bacon (STScI) / NASA)

ALIEN worlds that are friendly to life could reveal themselves by radio signals crackling from their magnetic fields.

When struck by high energy particles in the solar wind, an exoplanet's magnetic field may produce radio signals from auroras in the planet's atmosphere. While current telescopes have yet to pick up these crackles, it's an area worth exploring

The snag is that we would need a space telescope 100 times as sensitive as any planned to find auroras within a few dozen light years, because the Earth's atmosphere would absorb the low frequency signals.

That leads some planet hunters to doubt the idea's feasibility