NOVA: The Pluto Files Series

Public talks curated around NOVA: The Pluto Files that explores the rise and fall of America's favorite planet.

When the American Museum of Natural History's Hayden Planetarium stopped calling Pluto a planet, director Neil deGrasse Tyson found himself at the center of a firestorm led by angry, Pluto-loving elementary school students. But what is it about this cold, distant, icy rock that captures so many hearts? Now, almost 10 years after the news broke on the front page of The New York Times, "Pluto Not a Planet? Only in New York," and nearly four years after the IAU (International Astronomical Union) officially reclassified the ninth planet as a plutoid, NOVA travels cross-country with Tyson to find out. Based on Tyson's book of the same name, The Pluto Files premieres on PBS.

From Boston to California, Tyson's spirited journey explores the history of Pluto—from the time of its discovery to its fall from planethood. Along the way, Tyson meets a fascinating cast of characters, from scientists who argue over Pluto's status to die-hard "Plutophiles"—regardless of where they stand they have one thing in common: strong opinions about Pluto. The Pluto Files also includes special appearances by Stephen Colbert, Jon Stewart, Diane Sawyer, and Brian Williams, who share their affection for the former planet. "I'm sorry, I thought planets might be one of the constants in life," Colbert jests. "But scientists just love change more than anything else. I'm sorry that's not change I can believe in."

In California, Tyson sits down for a barbecue and celestial conversation with astrophysicists Mike Brown and David Jewitt. It was their desire to see beyond the outer solar system that led to the discovery of the Kuiper Belt and eventually the debate over Pluto's planetary status. Discovered by Jewitt and his colleague Jane Luu in 1992, the Kuiper Belt is a region of the solar system never before seen. Billions of miles wide, it's chock full of celestial objects, leftovers from the formation of the solar system 4.5 billion years ago. Most of these leftovers are much smaller than Pluto. But in 2005, Brown found something extraordinary: a Kuiper Belt object larger than Pluto. Was it the 10th planet? Was Pluto still a planet? The scientific community was faced with a problem—a Pluto problem.

The IAU, in charge of naming celestial objects, couldn't give Brown's discovery an official name until they decided what it was: a planet or an iceball in the solar system's deep freeze. That meant the IAU had to do something that hadn't been done since the ancient Greeks formally defined the word planet. The new definition of planet states that a planet must clear the neighborhood around its orbit—not good news for Pluto or Brown's discovery since they're both surrounded by Kuiper Belt objects.

So in 2006, after 75 years in the limelight, Pluto was no longer a planet. Many planetary scientists were upset with the news. Within days of the announcement, a petition signed by hundreds of scientists rejected the IAU decision. On his way back to New York, Tyson stops at John Hopkins University's Applied Physics Lab in Baltimore, Maryland, where he meets Alan Stern, a staunch Pluto supporter and one of the world's leading experts on Pluto. Stern is the principal investigator of the New Horizons mission—a nine-and-a-half-year voyage to Pluto, which launched in 2006. Stern's assessment of Pluto is that it is a new kind of planet, a dwarf planet. "It looked like the solar system consisted of four terrestrial planets, four giant planets, and misfit Pluto," says Stern. "But today, instead, we see a solar system with four terrestrial planets, four freakishly giant planets, and a whole cohort of Pluto-like objects that turn out to be the dominant class of planet in our solar system."

So then, what is Pluto? Is it a planet? Is it just an ice ball? The debate continues

Public talks curated around NOVA: The Pluto Files that explores the rise and fall of America's favorite planet.

When the American Museum of Natural History's Hayden Planetarium stopped calling Pluto a planet, director Neil deGrasse Tyson found himself at the center of a firestorm led by angry, Pluto-loving elementary school students. But what is it about this cold, distant, icy rock that captures so many hearts? Now, almost 10 years after the news broke on the front page of The New York Times, "Pluto Not a Planet? Only in New York," and nearly four years after the IAU (International Astronomical Union) officially reclassified the ninth planet as a plutoid, NOVA travels cross-country with Tyson to find out. Based on Tyson's book of the same name, The Pluto Files premieres on PBS.

From Boston to California, Tyson's spirited journey explores the history of Pluto—from the time of its discovery to its fall from planethood. Along the way, Tyson meets a fascinating cast of characters, from scientists who argue over Pluto's status to die-hard "Plutophiles"—regardless of where they stand they have one thing in common: strong opinions about Pluto. The Pluto Files also includes special appearances by Stephen Colbert, Jon Stewart, Diane Sawyer, and Brian Williams, who share their affection for the former planet. "I'm sorry, I thought planets might be one of the constants in life," Colbert jests. "But scientists just love change more than anything else. I'm sorry that's not change I can believe in."

In California, Tyson sits down for a barbecue and celestial conversation with astrophysicists Mike Brown and David Jewitt. It was their desire to see beyond the outer solar system that led to the discovery of the Kuiper Belt and eventually the debate over Pluto's planetary status. Discovered by Jewitt and his colleague Jane Luu in 1992, the Kuiper Belt is a region of the solar system never before seen. Billions of miles wide, it's chock full of celestial objects, leftovers from the formation of the solar system 4.5 billion years ago. Most of these leftovers are much smaller than Pluto. But in 2005, Brown found something extraordinary: a Kuiper Belt object larger than Pluto. Was it the 10th planet? Was Pluto still a planet? The scientific community was faced with a problem—a Pluto problem.

The IAU, in charge of naming celestial objects, couldn't give Brown's discovery an official name until they decided what it was: a planet or an iceball in the solar system's deep freeze. That meant the IAU had to do something that hadn't been done since the ancient Greeks formally defined the word planet. The new definition of planet states that a planet must clear the neighborhood around its orbit—not good news for Pluto or Brown's discovery since they're both surrounded by Kuiper Belt objects.

So in 2006, after 75 years in the limelight, Pluto was no longer a planet. Many planetary scientists were upset with the news. Within days of the announcement, a petition signed by hundreds of scientists rejected the IAU decision. On his way back to New York, Tyson stops at John Hopkins University's Applied Physics Lab in Baltimore, Maryland, where he meets Alan Stern, a staunch Pluto supporter and one of the world's leading experts on Pluto. Stern is the principal investigator of the New Horizons mission—a nine-and-a-half-year voyage to Pluto, which launched in 2006. Stern's assessment of Pluto is that it is a new kind of planet, a dwarf planet. "It looked like the solar system consisted of four terrestrial planets, four giant planets, and misfit Pluto," says Stern. "But today, instead, we see a solar system with four terrestrial planets, four freakishly giant planets, and a whole cohort of Pluto-like objects that turn out to be the dominant class of planet in our solar system."

So then, what is Pluto? Is it a planet? Is it just an ice ball? The debate continues

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