THE ENDLESS SEA

It is a boundless ocean, more than ten times wider than the entire planet Earth. Beneath the swirling clouds that cover Jupiter from pole to pole, the ocean has never seen sunlight, nor has it ever felt the rough confining contours of land. Its waves have never crashed against a craggy shore, never thundered upon a sloping beach, for there is no land anywhere across Jupiter’s enormous girth: not even an island or a reef. The ocean’s billows sweep across the deeps without hindrance, eternally.

Heated from below by the planet’s seething core, swirled into a frenzy by Jupiter’s hyperkinetic spin rate, ferocious currents race through this endless sea, jet streams howling madly, long powerful waves surging uninterrupted all the way around the world, circling the globe over and again. Gigantic storms rack the ocean, too, typhoons bigger than whole planets, hurricanes that have roared their fury for century after century. It is the widest, deepest, most powerful, most dynamic and fearsome ocean in the entire solar system.

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. What gives those clouds their colors? What lies beneath them? For more than a century astronomers had cautiously sent probes into the Jovian atmosphere. They barely penetrated the cloud tops before being crushed by overwhelming pressure.

But the inquisitive scientists from Earth persisted and gradually learned that some fifty thousand kilometers—nearly four times Earth’s diameter—beneath those clouds lies that boundless ocean of water, an ocean almost eleven times wider than the entire Earth and some five thousand kilometers deep. Heavily laced with ammonia and sulfur compounds, highly acidic, it is still an ocean of water, and everywhere else in the solar system where there is water, life exists.

Is there life in Jupiter’s vast, deep ocean?