"In its infancy, Earth was a primeval hell, a lifeless planet bombarded by massive asteroids and comets," reports Neil deGrasse Tyson, who goes on to muse: "How did it change from a raging inferno to a place we all know and love?"

That's a central issue occupying Nova: Origins (8 p.m. today and Wednesday, Channels 48, 16), the lively, four-part miniseries for which Tyson serves as tour guide from the beginning of time.

"Only when you know how something is born can you truly understand what has happened to it since then," and what its prospects are for the future, says Tyson, an astrophysicist and the director of New York's Hayden Planetarium at the American Museum of Natural History.

A subtitle for Origins, says Tyson, could well have been "The Search for Ourselves in the Cosmos." And there is new hope for easing our identity crisis, thanks to a growing collaboration across scientific disciplines.

Tyson views the collaborative process as a sort of intellectual liberation. And he points out that, oddly enough, it's a throwback to three or four centuries ago, when scientists remained generalists.

With increased specialization, says Tyson, came a range of different priorities:

Astrophysicists asked, "How did the universe get here?" Biologists asked, "How did life begin?" Geologists asked, "How did Earth begin?" Physicists asked, "What is the origin of the elements?"

"But today," says Tyson, "science in all of its disciplines has advanced to the point that we can now come back together, hold hands, sing 'Kumbaya,' and ask the same question: 'How did all of this get here?' "

Tyson has a gift for explaining vast or abstruse ideas in down-to-earth terms even a child can grasp.

When he mentions there are 100 billion stars in our galaxy, he makes that hard-to-fathom figure relatable by adding, "McDonald's has sold about 100 billion hamburgers."

During the final chapter of Origins, titled "Back to the Beginning," Tyson even lets his viewers get a peek at the big bang, right there in their living room.

For anyone with a TV set that receives its signals through the airwaves, not by cable, "all you need to do is change the channel until you come between two stations," he says. Most of the static represents stray radio waves. "But amazingly, about 1 percent of the snow and noise comes from microwaves produced in the big bang itself" - live, from 13 billion years ago.

"Right now," says Tyson, "we're all eavesdropping on the birth pangs of the cosmos."

And Origins covers plenty of ground after that.