Among the planets, Jupiter is definitely the solar system’s bad boy in disturbing the motions of all the planets and asteroids[, with] … a “lion’s share” of the mass of the entire planet family….

Astronomers tell us that there are about 10²³ stars in the universe. That’s a meaningful number to chemists—an Avogadro number of potential solar systems of which between 1 and 50 percent are estimated to have planets. … Planets are plentiful—and from this fact we can begin our exploration of how life might have evolved on any one of them.

At the planet’s very heart lies a solid rocky core, at least five times larger than Earth, seething with the appalling heat generated by the inexorable contraction of the stupendous mass of material pressing down to its centre. For more than four billion years Jupiter’s immense gravitational power has been squeezing the planet slowly, relentlessly, steadily, converting gravitational energy into heat, raising the temperature of that rocky core to thirty thousand degrees, spawning the heat flow that warms the planet from within. That hot, rocky core is the original protoplanet seed from the solar system’s primeval time, the nucleus around which those awesome layers of hydrogen and helium and ammonia, methane, sulphur compounds and water have wrapped themselves.

In some remote corner of the universe, poured out and glittering in innumerable solar systems, there once was a star on which clever animals invented knowledge. That was the haughtiest and most mendacious minute of ‘world history’—yet only a minute. After nature had drawn a few breaths the star grew cold, and the clever animals had to die. ... There have been eternities when [human intellect] did not exist; and when it is done for again, nothing will have happened.

Jupiter is the largest of all the solar system’s planets, more than ten times bigger and three hundred times as massive as Earth. Jupiter is so immense it could swallow all the other planets easily. Its Great Red Spot, a storm that has raged for centuries, is itself wider than Earth. And the Spot is merely one feature visible among the innumerable vortexes and streams of Jupiter’s frenetically racing cloud tops. Yet Jupiter is composed mainly of the lightest elements, hydrogen and helium, more like a star than a planet. All that size and mass, yet Jupiter spins on its axis in less than ten hours, so fast that the planet is clearly not spherical: Its poles are noticeably flattened. Jupiter looks like a big, colorfully striped beach ball that’s squashed down as if some invisible child were sitting on it. Spinning that fast, Jupiter’s deep, deep atmosphere is swirled into bands and ribbons of multihued clouds: pale yellow, saffron orange, white, tawny yellow-brown, dark brown, bluish, pink and red. Titanic winds push the clouds across the face of Jupiter at hundreds of kilometers per hour.