A team of astronomers has recently discovered three habitable alien planets that have Earth-like qualities. Interestingly, these newly discovered exoplanets are orbiting a nearby "ultracool dwarf star" called TRAPPIST-1, shedding more hints that life outside the solar system could be possible.

According to the study published in the journal Nature, these alien planets have almost the same size and temperature as the Earth and are in close proximity, located just 40 light years away. However, what makes this discovery extremely significant is the fact that these exoplanets are orbiting a tiny star such as TRAPPIST-1. Ultracool dwarf stars like TRAPPIST-1 usually have lower mass and have existed longer than the current universe, which means that significant amount of life could have evolved on the planets orbiting it. TRAPPIST-1's estimated age is around 1 to 10 billion years old, as per Popular Mechanics.

Gizmodo notes that this is the first time that researchers have found exoplanets that could be habitable as well as sustain liquid water and life. Also, because they are only 40 light years away, scientists will be able to conduct further research about the composition and characteristics of the said alien planets.

"What is super exciting is that for the first time, we have extrasolar worlds similar in size and temperature to Earth -- planets that could thus, in theory, harbor liquid water and host life on at least a part of their surfaces -- for which the atmospheric composition can be studied in detail with current technology," Michaël Gillon, lead researcher of the study, told Popular Mechanics.

In the past, scientists have usually observed bright stars because they are easier to spot. However, dim stars, though harder to locate, poses an advantage because they will not give off too much bright light, leading to an easier planetary observation. The scientists plan to use spectroscopy to identify the alien planets' atmospheric composition and chemical equilibrium, comparing it to those on Earth to see if life is indeed possible.

“This is basically a paradigm shift. If these planets have atmospheres, they really are the best places to look for life," Julien de Wit, study co-author, told Gizmodo.