Three 18th-century earthquakes changed the course of the Mississippi River, the continent of Africa was once located in the polar regions, and in 15 million years, Los Angeles will be a virtual suburb of San Francisco. So make your vacation plans accordingly.

"Planet Earth" is full of information that is absolutely fascinating and, for the layman, totally useless. But that doesn't detract from the worth and excellence of this new and gleaming seven-part PBS science series, premiering at 9 tonight on Channel 26 with "The Living Machine." That title refers to this watery verdant planet of ours, though it's not really ours. We're just on a generous time-sharing plan.

"Continental tectonics" sounds like the name of a sprawling conglomerate; actually, it describes the process of geological reconstruction that is a never-ending Earth project. The planet doesn't just rotate; while it moves, all kinds of remodeling and refurbishing are going on. Flux-o-matic. Narrator Richard Kiley tells us all these things and amazes us, but not so much as the filmic illustration, which globe-hops with mesmerizing agility.

We go down the Colorado River and into the Grand Canyon to see that yes, rocks do indeed tell time. We go to Edinburgh, where in the late 18th century it was deduced that Earth was not a trifling 6,000 years old as religious teaching theorized, but rather a whopping 4.6 billion years old, and getting older all the time. We fly in a specially equipped NASA jet along the San Andreas Fault -- "among the most studied faults in the world," Kiley says -- and are reassured that California will not sink into the Pacific Ocean as gossip has it, but instead gradually slide northward.

This is what will put Los Angeles and San Francisco in such close proximity that, says Kiley, the Giants and the Dodgers will be "cross-town rivals" again.

New Madrid, Mo., has a colorful history. The new New Madrid is over here, and the old New Madrid is over there -- sunk in the middle of the mighty Mississip', according to New Madrid's mayor, who drives around town in a landscaping truck. Old Man River, he must know somethin', and geologists spend their lives trying to find out precisely what.

Most spectacular of the ports of call on tonight's premiere is the Kilauea volcano in Hawaii, where scientists collect red-hot lava in coffee cans to better understand the shifting, whispering mush that makes up the planet's ever-lifting face. Who knows but that in time scientists will be able to say that the planet is not just 4.6 billion years old but is instead, say, more like 4.6 1/2 billion years old.

And what if, a viewer can't help thinking to himself, a couple of world leaders decide to interrupt all this activity by pressing a couple of apocalyptic buttons, and what took 4-point-however-many years to bring together humanity puts foolhardily asunder? Any program that extolls the glory of Earth and nature has inevitable nuclear questions hanging over it. "Planet Earth" will face these questions outright on its seventh and final installment, airing March 5.

A gorgeous and engrossing expedition, "Planet Earth" follows in the tradition of other memorable PBS informational adventures from "The Ascent of Man" to "The Brain." The series executive producer is Thomas Skinner, the producer Gregory Andorfer, and the writers of "Living Machine" Andorfer and Georgann Kane. They do not appear to have bitten off more of the planet Earth than they can chew.