Compression of iron in the cores of exoplanets of the super-Earth class and the formation of the magnetosphere

(ORDO NEWS) — The discovery of more than 4500 extrasolar planets to date has given rise to the need to model their internal structure and dynamics. As it turns out, iron plays a key role.

Researchers at the Livermore National Laboratory E. Lawrence (Lawrence Livermore National Laboratory, LLNL), USA, used the lasers of the National Ignition Facility scientific complex to perform experiments to construct a melting curve and determine the structural properties of pure iron at high pressures, reaching 1000 gigapascals (almost 10,000,000 atmospheres), which is three times the pressure in the Earth‘s inner core and almost four times the maximum pressure achieved in similar experiments before.

The team conducted a series of experiments to recreate the conditions in which a portion of iron is located when dipping to the center of the core of an exoplanet of the super-Earth class.

“The iron melt curve is important for understanding the internal structure, thermal evolution, and developmental potential of dynamo-generated magnetospheres,” said Rick Kraus, a physicist at LLNL and lead author of the new study.

The magnetosphere is thought to play a large role in determining the potential habitability of terrestrial planets, as it is of great importance for life on Earth. The Earth’s magnetic dynamo is generated in the outer liquid core, where convective mixing of iron flows takes place.

During the experiments, the team determined the duration of the maintenance of the dynamo during the solidification of the core with the formation of a hexagonal dense packing of atoms in the interior of exoplanets of the super-Earth class.

“We found that terrestrial exoplanets between 4 and 6 Earth masses would have the longest dynamos to provide a high level of shielding from cosmic rays,” Kraus said.


Contact us: [email protected]

Our Standards, Terms of Use: Standard Terms And Conditions.