Planets orbiting small stars like our sun likely experience the same dynamics that produces the life-shielding magnetic field here on Earth, a recent study finds.
Earth may not be such a special snowflake after all. According to a report from Phys.org, researcher at the University of Washington have reported that planets orbiting in the “habitable zones” of small stars would most likely have magnetic fields that protect them from radiation and help keep surface conditions constant.
The magnetic field of Earth comes from the core of the planet and is believed to deflect charged particles that make their way towards Earth from the sun. This keeps the atmosphere from dissipating into outer space. The magnetic field was formed as the metallic center of the planet cooled following its formation billions of years ago, and is believed to be one of the great protectors of the conditions necessary for life on Earth.
Stars like our own sun, ones with low mass, are prevalent in galaxies throughout the entire universe. Planets that orbit stars like ours are easy to study for astronomers because as they pass in front of their host star, they block out a greater proportion of the light. This makes planets orbiting these stars easier for researchers to spot.
Planets close to their host stars likely experience tidal heating, a phenomenon that occurs when the gravity of the sun is so strong that it locks planets into a constant orbit where the same side faces the sun at all times. This allows the center of the planet to absorb heat, which keeps the circulation of molten metals inside the planet’s core moving.
The recent study showed that simulations of planets orbiting their suns at different sizes and distances could offer insight into the dynamics that govern magnetic fields. According to lead author Peter Driscoll, “The question I wanted to ask is, around these small stars where people are going to look for planets, are these planets going to be roasted by gravitational tides?”
Driscoll and his team that planets that orbit small stars in eccentric or elliptical orbits have more circular orbits during times of extreme tidal heating. Once the heat circulates all the way through the planet, it loses any tidal heating.