Scientists have discovered two planets located nearby Earth that could potentially be habitable by human kind
The team of astronomers that includes researchers from the UK’s University of Hertfordshire and University of California Santa Cruz revealed that there have been discovered four planets orbiting the sun-like star, known as the tau Ceti.
They think that two of them can be named “Super-Earths”, as they have masses of around 1.7 Earth mass. Even though they are larger than Earth, they still remain the smallest planets to have ever been detected around the nearest sun-like stars.
“[The habitable zone] is the ‘Goldilocks’ region around a star where the planet is not too hot or too cold and thus is able to sustain liquid water on its surface,” Dr Fabo Feng said
He also added that the planets are most likely made of “rocks rather than ice”, which tremendously increases the chances of them supporting life.
The planets were discovered by monitoring the star for small variations in its movement that could have been caused by another planet’s gravitational pull.
“We measured the variation of the motions of the star through spectroscopic observations,” Feng said.
Spectroscopy is a special technique that “measures light that is emitted, absorbed, or scattered by materials.”
Specialists had to develop a certain sophisticated technique to detect what Feng calls “weak planetary signals”, due to the fact that the variations caused by a star and the ones caused by a planet are very similar.
“Together with colleagues in UK and US,” Feng said “I have detected the smallest movement of a star caused by planets.”