'Proxima b', a confirmed, potentially habitable earth-sized planet is mere 4.2 light years away

Tribune Web Desk

Chandigarh, May 30

An international team of scientists has confirmed a planet the size of the earth around the closest star in our solar system,  Proxima Centauri.

According to a newspaper published in the journal Astronomy & Astrophysics, the planet—called ‘Proxima b’—has a mass of 1.17 earths and is located in the habitable zone of Proxima Centauri.

Proxima Centauri is a red dwarf, much smaller and cooler than the sun, its habitable zone or Goldilocks zone — neither too hot nor too cold for liquid water to exist — is very close to the star. ‘Proxima b’ orbits about 20 times closer to its star than earth does to the sun, and a year on the planet is just over 11 earth days long.

It is believed this planet could be “likely” to be able to support alien life forms.

The new measurement indicates that ‘Proxima b’ is even more like our home planet, at least in size, than previous observations led scientists to think. The first indication of the planet’s existence was in 2013 by Mikko Tuomi of the University of Hertfordshire from archival observation data, with continued research following in 2016, said a report by the Independent.

The research team studied ‘Proxima b’ using the Echelle Spectrograph for Rocky Exoplanet and Stable Spectroscopic Observations, or ESPRESSO for short.

ESPRESSO is a Swiss spectrograph that is currently mounted on the European Southern Observatory’s (ESO) Very Large Telescope in Chile. Spectrographs observe objects and split the light coming from those objects into the wavelengths that make it up so that researchers can study the object in closer detail.

Proxima Centauri is approximately 4.2 light-years from the Sun, but Nasa estimates it would take approximately 73,000 years for us to reach the planet unless new technologies are developed.

Ionic propulsion, nuclear thermal propulsion, nuclear pulse propulsion, fusion rockets, and laser sails have all been considered as methods to travel to the planet.

“We were already very happy with the performance of HARPS, which has been responsible for discovering hundreds of exoplanets over the last 17 years,” said Francesco Pepe, a professor in the Astronomy Department in UNIGE’s Faculty of Science in a statement. 

“We’re really pleased that ESPRESSO can produce even better measurements, and it’s gratifying and just reward for the teamwork lasting nearly 10 years.”

Although ‘Proxima b’ is about 20 times closer to its star than the Earth is to the Sun, it receives comparable amounts of energy. If there is the liquid form on the planet, it could harbour life, but researchers said there is still much to be done before that can be confirmed.

Alejandro Suarez Mascareño, the article’s main author, said: “Confirming the existence of Proxima b was an important task, and it’s one of the most interesting planets known in the solar neighbourhood.”

“Is there an atmosphere that protects the planet from these deadly rays?” said Christophe Lovis, a researcher in the University of Geneva’s Astronomy Department, “and if this atmosphere exists, does it contain the chemical elements that promote the development of life?”

It is also possible that there could be a second planet orbiting the star, as the research team found evidence of a second signal in the data – but was unable to determine its origins.

“If the signal was planetary in origin, this potential other planet accompanying Proxima b would have a mass less than one third of the mass of the Earth. It would then be the smallest planet ever measured using the radial velocity method,” said Professor Pepe.