A New Study Reinforces The Theory That Ross 128b Exoplanet Might Host Liquid Water


A new study examining chemical compounds within the host star of the Ross 128b exoplanet, the second rocky planet within the habitable zone similar to Earth, showed that it is a temperate place that can hold liquid water, even if it is not precisely the twin of the Earth, as reported by EurekAlert.

The new work of a team led by Diogo Souto of Brazil’s National Observatory, including Johanna Teske of the Carnegie Institution, has determined for the first time the detailed chemical composition of the exoplanet’s host star, Ross 128. Understanding what elements are present in a star and in what concentrations¬†can help researchers estimate the composition of the exoplanets that orbit them, which can help predict how similar the planets are to Earth.

The Ross 128b exoplanet’s host star, like about 70 percent of all stars in the Milky Way, is a red dwarf, which is much colder and smaller than our Sun. Several planetary systems around red dwarfs have been in the news in recent years, including Proxima b, a planet that orbits the nearest star to our own Sun, Proxima Centauri, and the seven planets of TRAPPIST-1.

Ross 128b exoplanet can host liquid water

Using Sloan Digital Sky Survey’s APOGEE spectroscopic instrument, the team measured near-infrared light from the star to derive abundances of carbon, oxygen, magnesium, aluminum, potassium, calcium, titanium, and iron. “APOGEE’s ability to measure near-infrared light, where Ross 128 is brightest, was key to this study,” said Teske.

“It allowed us to address some fundamental questions about the earthly likeness of Ross 128b,” Teske added.

The team determined that Ross 128 star has iron levels similar to those of our sun. Although they were unable to measure their abundance of silicon, the iron-to-magnesium ratio indicates that the core of the Ross 128b exoplanet should be more significant than that of the Earth. Because they knew the minimum mass of Ross 128b and its stars’ chemical composition, the team was also able to estimate the exoplanet’s radius.

“It’s exciting what we can learn about another planet by determining what the light from its host star tells us about the chemistry of the system,” said Diogo Souto. “Although Ross 128b exoplanet is not the twin of the Earth, and there is still much that we do not know about its potential geological activity, we were able to reinforce the argument that it is a temperate planet that may host liquid water on its surface,” concluded Souto.


Related Posts