Super-Earths may be more habitable to alien life than Earth-sized planets because of magnetic fields

In the race to find a world beyond Earth that could harbor life, we’ve found more than 4,500 exoplanets — planets that exist outside the solar system. A few of these are thought to be habitable, but that doesn’t mean they look like Earth. Many of what we might call “super-Earths,” may be two to 10 times more massive than our planet. But there’s a lot we don’t know about the inner workings of these larger planets and whether they could actually support life.

A new study published year Science on ThursdayHowever, super-Earths show that it could be more life-friendly than smaller rocks like our planet. If that’s the case, alien hunters will more wisely spend their time scouring these larger worlds for signs of life.

Extraterrestrial habitability is complex, but there are a few basic ingredients you really need to sustain life — like the presence of actual water and an atmosphere that covers the planet and makes everything possible. things become warm and fuzzy. To maintain these, however, a planet needs to create a magnetic field that can protect it from the radiation of its host star. The Earth has a constant earth that protects us from being surrounded by dangerously charged particles from the sun. Without this so-called magnetosphere, a planet’s atmosphere would bleed and the surface would quickly turn into a barren wasteland.

The magnetosphere is created by an inversion of the planet’s core, when metals like iron in the liquid outer core solidify over time. But the freezing point of iron increases and decreases with the change of pressure. Planets larger than Earth experience more extreme pressure as you enter the core.

Because there’s so much we don’t know about how super-Earths work, Richard Kraus, a researcher at Lawrence Livermore National Laboratory in California and lead author of the new study, told The Daily Beast that there’s an important question he wants to answer: Can the iron in the “super-Earth” solidify and successfully create an active magnetosphere?

To figure this out, you have to literally simulate these out-of-this-world pressures. There’s only one place on Earth where we can do those kinds of experiments: the National Ignition Facility at Lawrence Livermore, which uses extremely hot lasers to create unstable temperatures and pressures. .

For this study, Kraus and his team irradiated a sample of an iron-containing material with 16 lasers to increase heat. They increased the intensity of these lasers to increase the sample’s pressure “gradually” without significantly increasing the temperature. Once the desired pressure was reached, the team used a special form of X-ray to see if the iron in the sample was a liquid or a solid in this state.


The National Ignition Facility at Lawrence Livermore National Laboratory.

Lawrence Livermore National Laboratory

The researchers were able to find the melting point of iron at pressures three times higher than what you’d find in Earth’s inner core. What they learned was that the iron metal in the outer cores of planets four to six times more massive than Earth would solidify much more slowly than a smaller planet,” which means are magnetic fields that can persist for longer periods of time,” Kraus said.

And if globulars last longer, then habitable conditions on super-Earths will be more protective and permanent than on smaller planets. If we’re trying to avoid betting on worlds beyond our solar system that are more likely to be inhabited by alien life, we might want to start paying more attention to the rocks. big.

Youjun Zhang, a planetary researcher at Sichuan University in China who was not involved in the study, told The Daily Beast: “Magnetospheres can protect organic life from harmful radiation and keep the climate intact. stable. “For the thousands of confirmed super-Earths, if they are habitable, then it doesn’t make sense to deny the possible existence of extraterrestrials.” Super-Earths may be more habitable to alien life than Earth-sized planets because of magnetic fields

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