Trappist-1 is a red-dwarf star ??the most common variety ??located some 40 light-years away in Aquarius. In 2015, astronomers discovered that Trappist-1 was host to three earth-sized planets. Then it came under the spotlight again in 2017 when NASA scientists found an additional four planets, taking the total up to seven. Trappist-1 is only fractionally larger than Jupiter in diameter; this image shows them on the same scale. This is the most terrestrial planets that have ever been found to orbit a single star, including our own Solar System.