A Super-Earth is an extrasolar planet with a mass higher than Earth’s, but substantially below the masses of the Solar System’s ice giants, Uranus and Neptune, which contain 15 and 17 Earth masses respectively.
The term super-Earth refers only to the mass of the planet and so does not imply anything about the surface conditions or habitability. The alternative term gas dwarfs may be more accurate for those at the higher end of the mass scale, as suggested by MIT professor Sara Seager, although mini-Neptunes is a more common term.
Astronomers have found a temperate planet a bit bigger and bulkier than Earth orbiting a small star just 40 light-years away. The newly announced world could be among the best targets to search for signs of life elsewhere in the cosmos.
“Small worlds are common,” says Lauren Weiss of the Université de Montréal. And this planet, she says, is one of the closest known rocky worlds outside our solar system. “It’s in our sun’s backyard.”
Whether there is actually water on the planet or not depends on the composition of its atmosphere and other factors, including the presence of a magnetic field, such as the one Earth has, but the most important thing is for the planet to “fulfil the requirements to have water,” which means that it must be in its star’s habitable zone, Murgas said.
Regarding the age of the planet, the authors of the study said that it probably formed in a manner similar to Earth and its star is probably 5 billion years old, about the same age as the Sun, although the age of M-class stars is hard to determine for a variety of factors, the Spanish researcher added.
In the coming decades, LHS 1140b is sure to be investigated much more intensively, an ongoing project for the powerful next-generation telescopes, including the James Webb instrument and the E-ELT device, which will be installed in Chile and — within a few years — will be able to study the system and try to detect its atmosphere, along with other characteristics.