National Broadcast premiere on PBS on Thursday, October 25 at 10 pm ET. (Check local listings.)

In a quiet and meditative voice, Patricio Guzman (Salvador Allende) recalls his childhood when Chile was "a haven of peace, isolated from the rest of the world." Now its Atacama Desert has brought astrologers from all over the globe to look at the stars. At 10,000 feet above sea level with no humidity, it is one of the driest places on the earth. In fact, when viewed from outer space, the desert shows up as a brown spot.

The astronomers gathered there are on a quest to discover the origins of the planet, humankind, and the rest of the galaxy. The very articulate astronomer Gaspar Galaz believes that this search is both scientific and religious. Another dimension of his work involves looking at the nature of time and realizing how ephemeral everything is — including stars and planets.

Another group in the Atacama desert is on another kind of quest. Since 1990 relatives of missing sons and daughters, husbands and wives have been searching for their remains: nearly 30,000 were slain by the August Pinochet dictatorship and many more just disappeared. Seventy-year-old Victoria has spent many years digging for her brother and only found bits and pieces of him. She feels cut off from society and sees herself and others on the same quest as Chile's lepers.

At one point Galaz is asked the difference between the astronomers and those searching for their loved ones: "We can sleep peacefully at night and they can't." Although the past is accessible to those who want to sift through the desert sand, Guzman notes that his nation still has not come to terms with the past — namely, the marginalization of the Indians who were part of a culture going back 10,000 years.

With a lyricism that is rare in documentaries, this filmmaker has fashioned a bright star of an experience with its nuanced treatments of astronomy and those searching for the disappeared and a possible closure to their grief. Nostalgia for the Light by Patricio Guzman is a beautifully crafted work the stirs our hearts and minds.

Special featues on the DVD include: Five short films by Patricio Guzmán on astronomy, the cosmos and the history of Chile