In the past few years, while the world has been preoccupied trying to deal with those who believe a bevy of beautiful virgins will greet them in heaven if they kill enough people, an agreed upon story of how the universe and humanity actually came into existence – “a new version of Genesis,” as the television series “Nova” put it in its “Origins” series this week – has been solidifying amongst scientists. “No science achieves maturity without precision data,” writes Neil DeGrasse Tyson, Fredrick P. Rose director of the Hayden Planetarium at the Museum of Natural History and host of the Nova show, in the companion book, (W.W. Norton, $27.95), he has written with Donald Goldsmith. “Cosmology has now become precision science.”

In the book and the television program, Mr. Tyson sets about establishing, in a manner comprehensible to a lay audience, the current state of the science. The book lays out the story in stately chronological fashion, breaking it into five parts: the origins of the universe, then of the galaxies, then stars, then planets, and finally life. Relatively little space is dedicated to the familiar, relatively recent periods of history -the disappearance of dinosaurs, the emergence of mammals, and so on. Rather, this book luxuriates in describing what was going on during the 10 billion years between the Big Bang and when life as we know it began.

The four-hour series, which began last night and continues today on PBS (it will be reshown the afternoon of Sunday, October 3, on WNET), starts in the middle of the story, with the formation of the planets, including Earth. As you might expect, it employs some pretty spectacular special effects, and it hangs its narrative thread around the stories of the scientists who made discoveries that led to or helped confirm the now-accepted theories.

So in the first hour we get Bill Hartmann, the man who first posited that the moon was formed after a Mars-size object hit Earth 50 million years after Earth was formed – this idea was inspired by estimates of the age of the rocks brought back from the moon, but it took about ten years for it to be accepted. We proceed in the second hour to the very beginnings of life, which may have been created and snuffed out many times in the early years.

The third hour, titled “Where Are the Aliens?” is by far the most engaging; it starts out with Mr. Tyson demonstrating the diversity of life on Earth as he strolls through Times Square pointing out the variety of denizens there, including punks, people dancing as they cross intersections, and the Naked Cowboy (who even gets a short interview). The final hour takes us back to the beginning of the universe, saving the hard physics stuff for the good students who have stuck with the series so far.

If you have made it that far, however, it’s probably time to turn to the book, which by its nature is better at making the physics comprehensible, and in separating which theories are now pretty well accepted and confirmed from those that are still big question marks. Take “dark matter,” for instance. We don’t what it is, where it is, or even if it’s really matter, but all data suggests that there must be something out there that accounts for the mass we know must be in the universe but have not been able observe directly.

A subsequent chapter on “dark energy” provides rougher sledding, but I believe I’ve gotten that the sum of the ratio of the density of matter to the universe’s density and the ratio of the density of energy to the universe’s density should equal one, assuming the universe is flat. A good index and glossary – essential to any such introductory work – make it easy to double-check.

Several people have suggested that Mr. Tyson could be the next Carl Sagan – the next great popularizer of science. Like Sagan, who hosted PBS’s “Cosmos” series, Mr. Tyson is a New York native (Sagan was from Brooklyn; Tyson is from the Bronx), and in fact Sagan mentored Mr. Tyson in his early days as an astrophysicist. Their styles are quite different – Mr.Tyson’s television presence in “Origins” is much less commanding than Sagan’s was, though that means he comes across as less arrogant than Sagan – Mr. Tyson might be better suited to our current age.

Mr. Tyson has an obvious enthusiasm for the material and I wish that, both in the book and the series, he had displayed it more. In the “Nova” show, he describes how, as a child, he saw the moon through binoculars on the roof of the “prophetically named” Skyview apartments and wondered how it was formed. He also visited the Hayden Planetarium as a 9-year-old and decided he wanted to be an astrophysicist, “although I could barely pronounce the word.” Both his speaking and his writing would benefit from more such personal asides. His loopy and appeal ing sense of humor, which I have seen him exhibit as a speaker at the Museum of Natural History, shows up more frequently in the book than in the “Nova” show.

The discovery in the past decade of more than 1,000 planets outside our solar system; the recently-created image of the universe at its beginning as lumpy contours of matter and energy; new discoveries of life in airless, lightless corners of Earth – all of this is very big, underreported news. Mr. Tyson is a welcome messenger.

Mr. Melloan is a writer living in Manhattan.