Imagine traveling 11 light years to borrow a cup of sugar.
Well, that may be a possibility, according to new research led by Diogo Souta of Brazil’s Observatório Nacional.
Following last year’s discovery of exoplanet Ross 128 b—a mere 11 light years from Earth—new work by Souto and Carnegie Science’s Johanna Teske has determined detailed chemical abundances of the planet’s host star, Ross 128.
This is one giant leap toward better understanding exoplanets—celestial bodies orbiting outside our Solar System. And may help lead us to other worlds similar to Earth.
“Until recently, it was difficult to obtain detailed chemical abundances for this kind of star,” Souto, who last year developed a technique for taking these measurements, said in a statement.
Using the Sloan Digital Sky Survey’s APOGEE spectroscopic instrument, the team evaluated the star’s near-infrared light to identify levels of carbon, oxygen, magnesium, aluminum, potassium, calcium, titanium, and iron.
“The ability of APOGEE to measure near-infrared light, where Ross 128 is brightest, was key for this study,” Teske said. “It allows us to address some fundamental questions about Ross 128 b’s ‘Earth-like-ness.’”
A young star’s chemistry can influence its overall makeup. In this case, Ross 128 boasts iron levels similar to our Sun; its ratio of iron to magnesium indicates that the core of its planet, Ross 128 b, should be larger than Earth’s.
The team was also able to estimate the planet’s radius, based on its minimum mass and stellar abundances.
These details, as reported by Carnegie Science, can be used to calculate a planet’s bulk density and verify its surface structure.
For instance, those with radii greater than about 1.7 times Earth’s are likely surrounded by a gassy envelope, like Neptune. Those with a small radii—such as Ross 128 b—are likely to be more rocky, like Earth.
By taking Ross 128’s temperature, meanwhile, scientists were able to forecast how much of the host star’s light reflects off the exoplanet’s surface, revealing that our neighbor likely has a temperate climate.
“It’s exciting what we can learn about another planet by determining what the light from its host star tells us about the system’s chemistry,” Souto said.
“Although Ross 128 b is not Earth’s twin, and there is still much we don’t know about its potential geologic activity,” he continued, “we are able to strengthen the argument that it’s a temperate planet that could potentially have liquid on its surface.”
Let us know what you like about Geek by taking our survey.