Several Earth-like Planets Are Nearby

In 2017, scientists announced that using the Spitzer Space Telescope, they discovered seven Earth-sized and Earth-like planets orbiting a star located 40 light-years away from us, known as Trappist-1. Among these, three (TRAPPIST-1 e, TRAPPIST-1 f, TRAPPIST-1 g) are in the habitable zone, meaning the presence of liquid water on their surfaces is likely, although water presence is possible on all seven planets. The planets orbit close to their star, and their orbits are also closely positioned to each other. According to researchers:

The question is no longer whether we will find a second Earth, but when.

The James Webb Space Telescope, which is set to launch in 2021, will have greater sensitivity and will be able to detect water, methane, oxygen, ozone, and other components in the atmospheres of exoplanets. From this, they can infer many things, such as the presence of living organisms, as they emit methane.

The head of the research team, Michael Gillon, added that Trappist-1 is an ultra-cool dwarf star—much smaller and colder than our Sun. Moreover, this type of celestial body is much more common in our galaxy than Sun-like stars. They are approximately in the ratio of a basketball to a golf ball. Because of this, the discovered planets also orbit extremely close to Trappist-1,” he explained.

There is particularly good reason to believe that one of the planets found in the habitable zone is covered in liquid water. This is promising in the search for extraterrestrial life.

– stated Gillon. By the way, this planet likely has only one side facing Trappist-1 since the planets' orbits are “tidally locked,” meaning they always show the same side to the central star and are also in resonance with each other (similar to how the Moon shows its face to the Earth),” he added.

The planets of the dwarf star orbit so closely to each other that one can observe the surface of one from the other as if they were moons.

Sources:
Wikipedia
24.hu