This planet was found by astronomers from the University of California, Santa Cruz, and the Carnegie Institution of Washington. It resides within the habitable zone of the red dwarf star Gliese 581, an area considered suitable for human habitation due to the possibility of water on the planet’s surface.
According to scientists, water and an atmosphere are crucial factors for a planet to maintain life. They have named this planet Gliese 581g. It has been determined that the planet has a mass 3 to 4 times that of Earth and completes its orbit in less than 37 days.
The planet’s mass suggests that it may be composed of rocky material, and its gravity is substantial enough to support an atmosphere, as noted by Steven Vogt, the lead researcher of the discovery. Researchers estimate that if Gliese 581g has a rocky composition similar to Earth’s, its diameter would be approximately 1.2 to 1.4 times that of Earth.
Vogt believes that there are still many more planets like Gliese 581g (highlighted in green) in the universe.
Furthermore, the surface gravity of this planet may be equivalent to or slightly lower than Earth’s, making it feasible for humans to move around comfortably. Gliese 581g was discovered during the Lick-Carnegie Exoplanet Survey, which involved 11 years of observing the red dwarf star Gliese 581, located 20 light-years away from Earth.
While 11 years of observation may be considered short in the field of astronomy, the distance of 20 light-years, roughly equivalent to 117.5 trillion miles, is relatively close. It is worth noting that it takes only 8 minutes and 30 seconds for sunlight to reach Earth from our own Sun.
The newly discovered planet is tidally locked to its parent star, meaning that one side of the planet always faces the star, basking in perpetual daylight, while the other side remains in darkness. The surface temperature of the planet gradually decreases as it moves toward the dark side and increases as it approaches the light side. Scientists estimate that the habitable zone for potential human settlement lies between the light and dark regions.
Researchers have estimated the average temperature on the planet to range from -31 to -12 degrees Celsius. However, they emphasize that the actual temperature can fluctuate from “scorching heat on the star-facing side to icy coldness in the dark side.”
With the discovery of this planet, there are now a total of six known planets orbiting the red dwarf star Gliese 581. This is the largest number of planets discovered in a planetary system outside our own solar system. Similar to the planets in our solar system, these planets around Gliese 581 also have circular orbits.