The Moon will squeeze past the planet Saturn tonight. They climb into view about 9:30 or 10. Saturn looks like a bright star. As seen from most of the United States, it’ll pass just a fraction of a degree from the Moon.

One of Saturn’s moons is one of the more interesting objects in the solar system. Geysers of water and ice erupt from cracks in its crust. The geysers feed one of Saturn’s rings. And the source of the geysers – a global ocean of liquid water – is considered one of the best places to look for life.

Enceladus isn’t very big – a bit more than 300 miles in diameter. It’s caught in a gravitational tug-of-war between Saturn and another moon. That stretches and squeezes Enceladus, generating heat. The heat has melted some of its ice, creating a global ocean well below the surface. The ocean could be several miles deep.

Some of the ocean’s water escapes through cracks in the crust near the south pole. Known as “tiger stripes,” they’re warmer than the surrounding landscape. They spew enough water and ice to fill up an Olympic swimming pool in less than an hour. Some of the ejected material enters orbit around Saturn, forming a wide but faint ring.

The ocean appears to contain all the ingredients for life: water, a source of energy, and a good mix of chemicals. Future missions may fly through the geyser plumes to hunt for microscopic life.

We’ll talk about a search for intelligent life tomorrow.

Script by Damond Benningfield