The idea of humans moving to and living on a life-sustaining planet other than Earth is very exciting and even seems to be the plot to many popular movies. As it turns out, this isn’t completely science fiction. Scientists at NASA are always on the lookout for planets that could be the home of lifeforms or of liquid water, which is essential for the survival of the multicellular organisms that live on our planet Earth. This past February, scientists at NASA published the most recent findings of NASA’s Spitzer Space Telescope: three newly discovered Earth-sized planets orbiting around a star known as TRAPPIST-1.

Four Earth-sized planets were already known to orbit around TRAPPIST-1, but the discovery of three more planets gives scientists at NASA much more data to study the atmospheric conditions necessary for a habitable planet.

TRAPPIST-1 is an ultracool dwarf star, meaning it is a much smaller and much cooler star than the Sun. It is located in the constellation Aquarius, about 40 light-years away from us on Earth. Five of the planets orbiting TRAPPIST-1 are similar in size to the Earth, while the other two have a size somewhere in-between that of Mars and Earth. The estimates of the mass of the first six planets suggest that the planets are very rocky, while the furthest, seventh planet has a low density that scientists are hopeful could mean the presence of an icy layer over the planet.

 One cool discovery is that the planets are tidally locked to their star, which means that one side of the planet is perpetually facing the star while the other side is in perpetual night. The weather conditions of these planets could be radically different from Earth’s. Perhaps the most exciting discovery is that all seven planets have temperatures low enough to make the presence of liquid water possible.

Hopefully, after more in-depth analysis of these planets, scientists will learn more about the conditions necessary for a planet to sustain life.


  1. Gillon, M., et. al. (2017). Seven temperate terrestrial planets around the nearby ultracool dwarf TRAPPIST-1. Nature. 542, 456–460
  2. NASA Telescope Reveals Largest Batch of Earth-size, Habitable-zone Planets Around a Single Star. NASA. Retrieved March 3, 2017, from

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