JupiterJupiter is the grandest of all planets. It is by far the largest planet in the solar system and among the brightest objects in the night sky, and its calming presence has inspired humans for centuries. Jupiter was the 'beloved star' of the ancient Sumerians and Babylonians, the first serious observers of the planets, and the Pioneer and Voyager spacecraft visited it in the 1970s. Now it is being scrutinised as never before by NASA's Juno spacecraft,