Three Earth-Like Planets Discovered, And They Might Be Habitable

Three Earth-like planets were discovered recently; according to a study published today, scientists operating the TRAPPIST telescope have discovered three exo-planets which stand out from the rest because of a single factor: they could be our best shot at finding signs of alien life.

According to The Washington Post, the three Earth-like planets discovered today were found orbiting a dim, far away star called TRAPPIST-1, named for the telescope array used to discover them (Transiting Planets and Planetesimals Small Telescope). The three Earth-like planets orbiting TRAPPIST-1 were discovered by measuring the steady dimming of the star when the planets crossed the star’s orbit. According to the scientists who discovered TRAPPIST-1 and the three Earth-like exo-planets, the distance between TRAPPIST-1 and the planets themselves is one of the strongest indications that the planets could be brimming with alien life.

The three Earth-like planets orbiting TRAPPIST-1 are in the so-called “goldilocks zone,” where they’re not too far away from the star to be frigid wastelands, like Pluto, and they’re not so close to the star that they’re boiling uninhabitable rocks like Mercury and Venus. The three Earth-like planets are also promising because of their composition; they’re reportedly rocky planets, like Earth, rather than ice or gas giants like Pluto and Jupiter, respectively. Due to the planets’ composition, their distance from their star, and their regular orbits, it’s likely they could have liquid water, a key component to life on Earth.

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According to The Washington Post, TRAPPIST-1 and its three Earth-like planets are fairly close by astronomical standards – only 40 light-years away. It’s still a relatively impossible distance to fathom, but in terms of the size of our galaxy, TRAPPIST-1 is practically a next-door neighbor.

Still, it’s not likely scientists will discover life on these three Earth-like planets anytime soon. The planets are promising, but there are still some rather astronomical odds to contend with. According to the researchers who published the study, the planets are likely “tidally locked,” meaning they have one hot side and one cold side. The hot side is just a little too close to TRAPPIST-1 to be habitable by Earth standards.

Certain regions of those three Earth-like planets, however, could be just the right temperature for liquid water to be present – allowing simple life to evolve. Additionally, the cloud cover and geothermal activity of the Earth-like planets could mean they’re a little closer to habitability than other planets, astronomers have recently discovered.

TRAPPIST-1, the ultracool dwarf star with three Earth-like planets in its habitable zone: https://t.co/No2OAooWcc

— Paul McAuley (@UnlikelyWorlds) May 2, 2016

TRAPPIST-1, the star which the Earth-like planets orbit, is reportedly a “dwarf star” – many times smaller than our sun, and a great deal cooler, hence, its dim coloring. According to the researchers, this is a very good thing for the chances that life might be present on the three Earth-like planets. By orbiting a star much smaller than our own, it’s less likely that the planets themselves are bathed in deadly amounts of radiation – a prohibitive factor for many of the larger stars which have exoplanets orbiting them.–

No single factor makes these three Earth-like exo-planets particularly fascinating, it’s the combination that makes them good candidates for finding alien life. They’re not too hot, not too cold, they’re stable, they’re rocky, and they’re orbiting a small star much less hostile to life than a larger star would be. Taken together, it’s no wonder the researchers behind TRAPPIST and the discovery of TRAPPIST-1 are so excited – well, cautiously optimistic anyway.

“This really is a paradigm shift with regards to the planet population and the path towards finding life in the Universe,” said Emmanuel Jehin, a co-author of the study published in the journal Nature, reports USA Today.

[Photo Illustration by Ames/JPL-Caltech/NASA via Getty Images]