A mere 11 light-years away from our Solar System, a newly discovered exoplanet is the second-closest we’ve ever found that’s temperate enough to potentially host and sustain life. The Earth-sized exoplanet was just discovered and scientists are already searching for signs of life.
Ross 128 b orbits the inactive red dwarf star, Ross 128, in the system’s “Goldilocks zone.” This zone is known as the area in perfect distance from a star to support life. The planet is also probably rocky, not gaseous; and it’s at a distance from its star that means the temperature could be hospitable to life as we know it.
It was found using the European Southern Observatory’s High Accuracy Radial velocity Planet Searcher (HARPS) in Chile – the most precise instrument of its kind. And it took researchers a long time to nail down. “We started to observe this star in July 2005,” astronomer Nicola Astudillo-Defru of Geneva Observatory told ScienceAlert. “Since 2013, our monitoring started to be more intense, and only after acquiring 157 observations was the signal of the planet strong enough to be detected.”
The researchers were able to discover the planet using the radial velocity method of planet detection. This method differs from the transit method we usually hear about but it shows this technique still has a whole lot of potential for finding new exoplanets.
Here’s what we know about Ross 128 b so far. It’s 1.35 times the mass of Earth. This means it’s most likely a rocky planet since – as far as we know at least, gas planets tend to be giants.
That’s the other point in favour of Ross 128 b being a rocky planet: it’s relatively close to its host star. In fact, it’s 20 times closer to its star than Earth is to the Sun, and completes an entire orbit in 9.9 days.
Why isn’t it too hot for life? Ross 128 is a cool, faint red dwarf. It emits less radiation than our yellow Sun, so Ross 128 b receives only about 1.38 times more irradiation than Earth. Its equilibrium temperature is estimated to be between -60 and 20 degrees Celsius (-76 to 68 degrees Fahrenheit). –Science Alert
Ross 128 also has fewer flares than most red dwarfs, such as Proxima Centauri, which has its own exoplanet, Proxima Centauri b. Conditions on Ross 128 b are expected to be much more stable than those on Proxima Centauri b.
We started to observe this star in July 2005. Since 2013, our monitoring started to be more intense, and only after acquiring 157 observations was the signal of the planet strong enough to be detected.”
What we don’t know yet is whether Ross 128 b has an atmosphere – that is something that is best determined by the transit method. But the Extremely Large Telescope, currently under construction and due to see first light in 2024, will be powerful enough to image the planet directly, and hopefully, detect the biomarkers that indicate life.
“We have some ideas about which biomarkers to search for. Of course, it is only based on what we know on Earth,” Astudillo-Defru explained.