In the last week of February, NASA announced the discovery of a spectacular “sister solar system,” a mere 39 light-years away, boasting not one, but seven Earth-size planets, all of which huddle around their ultra-cool dwarf star TRAPPIST-1, much like a family around a campfire.
They appear to be rocky; have surface temperatures ranging between a life-friendly 32 to 212 degrees Fahrenheit; and even host liquid water.
Nature describes the star system as a “compact analog of the inner solar system.” It’s so compact, in fact, that if you were standing on the surface of one of these planets, the neighboring planets would sometimes appear even larger than our Moon does to in our own sky.
The closest planet only takes 1.5 days to orbit the parent star; the sixth planet, 13 days. Compare that to our own solar system, where the closest planet, Mercury, takes 88 days to orbit the Sun and Neptune, the farthest planet, takes 165 years.
h/t: SCIENCE ALERT