Tidal Extremes From Dwarf Stars Could Sterilize Two-Thirds of Planets But Hundreds of Millions May Still Harbor Life While in the Habitable Zone

The majority of stars in the Milky Way are smaller and cooler than the Sun in the Solar System, with billions of planets orbiting them. However, these planets need to be situated close to their small stars to maintain habitable conditions, which exposes them to intense tidal forces.

In the study, titled "The Orbital Eccentricity Distribution of Planets Orbiting M Dwarfs" published in the Proceedings of the National Academy of Sciences, University of Florida, astronomers provided hope for the possibility of life beyond the Solar System. The research shows that one-third of the most common planets in the galaxy could potentially reside within the habitable zone.

Planets in the Habitable Zone

The team of astronomers has found that around two-thirds of planets orbiting small stars could be sterilized by extreme tidal forces, leaving one-third potentially habitable with liquid water, Phys.org reported. The research focuses on exoplanets orbiting red dwarf stars, which make up the majority of stars in the Milky Way.

Astronomy professor Sarah Ballard and doctoral student Sheila Sagear emphasize the significance of studying planets around these small stars, as they offer potential targets in the search for habitable worlds. These planets orbit close to their stars, within the habitable zone where liquid water could exist, making them prime candidates for hosting life.

While red dwarf stars are common in the galaxy, the environment surrounding them differs from our solar system. As per Forbes, the habitable zone is much closer to the star due to its lower light and heat radiation. However, planets in close proximity to the star are vulnerable to flares and tidal forces, which could hinder the formation of life.

The study suggests that hundreds of millions of planets in the Milky Way could be potentially habitable. More so, it contributes to the ongoing exploration of exoplanets and highlights the importance of studying planets orbiting small stars in the search for extraterrestrial life.

Assessing Eccentricity of Orbits Around M Dwarf Stars

Universal-Sci.com reported that researchers assessed the eccentricity of over 150 exoplanet orbits around M dwarf stars, which are similar in size to Jupiter. They found that planets in close proximity to their stars, comparable to the distance between Mercury and the sun, are more susceptible to tidal heating caused by their irregular orbits.

This heating process, generated by gravitational forces and friction, could render the planets uninhabitable by evaporating any potential liquid water. However, this phenomenon is only relevant for small stars where the habitable zone is within reach of tidal forces.

They used the data from NASA's Kepler telescope, which detects exoplanets as they pass in front of their host stars, and incorporated distance measurements from the Gaia telescope.

The analysis showed that stars with multiple planets have a higher chance of having orbits suitable for liquid water, with approximately one-third of the studied planets potentially being habitable, offering numerous targets for studying extraterrestrial life in the Milky Way.

This discovery holds significant implications for the future of exoplanet research, as it highlights the importance of studying smaller stars and their associated planets. By focusing on these M dwarf stars, scientists hope to uncover groundbreaking insights and make significant strides in our quest to discover life beyond Earth.

Check out more news and information on Exoplanets in Science Times.