Recently, the existence of a planet the size of Earth has been confirmed. Proxima b, the planet in question, has a mass of 1.17 Earth masses, and it’s situated in the habitable area of its star.
Such a discovery was possible thanks to ESPRESSO, the Swiss-developed spectrograph. Here are the latest details.
Proxima b Could Be the Ideal Candidate for Biomarker Research
Proxima b was first detected in 2016 with the help of an older spectrograph, HARPS, which measured a low disturbance in the star’s velocity, indicating a companion’s presence. ESPRESSO, on the other hand, has realized radial speed measurements on the star Proxima Centauri, with an accuracy of 30cm/s (approximately three times more precise than that obtained with HARPS).
The measurements have also clarified that the lowest mass of Proxima b is 1.17 earth masses and that it orbits around its star in 11.2 days. Michael Mayor, the architect of all ESPRESSO-type instruments, praised the spectrograph’s performance, saying: “ESPRESSO has made it possible to measure the mass of the planet with a precision of over one-tenth of the mass of Earth.”
Even if Proxima b is almost 20 times closer to its star than our planet is to the Sun, it gets comparable energy. Its surface temperature could indicate that water (if there is any chance to be) is in liquid form, and might support life. But, it could still be too early for scientists to indicate that life can develop there. Also, the Proxima star is an active red dwarf that assaults its planet with X rays, getting almost 400 times more than our planet.
In the meantime, the accuracy of the measurements realized by ESPRESSO could bring another surprise. Scientists have discovered proof of a second signal in the data, without being able to set the final cause behind it. “If the signal were planetary in origin, […] it would then be the smallest planet ever measured,” stated Francesco Pepe, a professor from the UNIGE’s Faculty of Science.