Potential Existence Of Liquid Water On The Surface
Diogo Souto, from the Observatório Nacional in Rio de Janeiro, Brazil, and colleagues reported that just like Earth, the planet is likely a rocky and temperate world, which means it can potentially have liquid water on its surface.
For the study published in Astrophysical Journal Letters, the researchers looked at the chemical composition of the planet's host star.
In their infancy, stars are enveloped by a disk of gas and dust that later form into planets. The star's composition influences the elements in the disk and thus, the main influencer of the structure and composition of the resulting planets.
The researchers were able to determine that the star is abundant in iron, magnesium, oxygen, aluminum, calcium, carbon, potassium, and titanium.
The researchers were also able to estimate the mass ratio of the core and mantle layers of Ross 128 b using the planet's iron and magnesium levels. Planets with radii that is 1.7 times larger than that of Earth's tend to have a gaseous envelope, which limits their odds for habitability. Planets with smaller radii tend to have rocky surfaces and Ross 128 b falls into this category.
"Mass-radius modeling of Ross 128 b indicates that it lies below the pure-rock composition curve, suggesting that it contains a mixture of rock and iron, with the relative amounts of each set by the ratio of Fe/Mg," the researchers wrote in their study.
The researchers also made temperature measurements, which revealed that the planet likely has a temperate climate. Souto and colleagues found that the temperatures near the surface of the host star are around 3,000 degrees Celsius.
They were able to determine the amount of energy that Ross 128 b receives using the exoplanet's radius and orbital distance from the star.
"Although Ross 128 b is not Earth's twin, and there is still much we don't know about its potential geologic activity, we were able to strengthen the argument that it's a temperate planet that could potentially have liquid water on its surface," Souto said.
The findings bolster the idea that Ross 128 b is Earth's second-closest potentially habitable neighbor next to Proxima B.