New findings, published in the Journal Astrobiology, showed that Earth-like planets, which orbit close to small stars, could have magnetic fields that can protect them against stellar reaction, a characteristic which may conduct to life.
The Earth’s magnetic field is vital for life since it diverts solar wind and keeps the planet’s atmosphere in place, according to European Space Agency. Other planets, such as Mars, have a naked atmosphere, so life is more difficult to have existed.
However, researchers from the University of Washington used computer simulations to recreate the planets that are close to low-mass M dwarf stars and found “tidally locked” Earth-like planets may have these magnetic fields.
Tidally locking occurs when the gravitational gradient makes one side of a celestial body always face another, just like the Moon does to the Earth. Planets orbiting low-mass stars, the most common in the galaxy, should be close to them to occupy what it’s called “the habitable zone”.
According to Space.com, “Strong heating of a planet at a single point can change or even control how much weathering occurs on the planet, which can lead to significant and even unstable climate changes,” making the planet uninhabitable. That is why a magnetic field is needed.
Getting close to these stars also provokes tidal heating, which is when the energy is dissipated as heat in either the surface ocean or interior of a planet or satellite. In Jupiter’s moon, for example, this phenomenon causes friction in the planet’s layers.
Nonetheless, tidal heating could actually aid a planet’s ability to dissipate heat. “I was excited to see that tidal heating can actually save a planet in the sense that it allows cooling of the core. That’s the dominant way to form a magnetic field,” said Rory Barnes, an assistant professor of astronomy, in a press release.
“These preliminary results are promising, but we still don’t know how they could change for a planet like Venus, where slow planetary cooling is already hindering magnetic field generation,” said Peter Driscoll, lead author of the study. “In the future, exoplanetary magnetic fields could be observed, so we expect there to be growing interest in this field going forward,” he added.