Nova

Why are birds the only dinosaurs still alive today? Rare fossil discoveries are revealing the secrets of bird evolution, telling the story of how some resilient feathered dinos became the vast array of colorful bird species that fill our skies.

From a dwarf planet that looks like a deflated football, to a tiny moon with cliffs taller than Mt.

Egyptian desert fossils reveal clues to the evolution of the biggest animals on Earth.

Egyptian desert fossils reveal clues to the evolution of the biggest animals on Earth.

A spectacular fossil graveyard reveals a 43-million-year-old whale that had four legs and could walk.

Egyptian desert fossils reveal clues to the evolution of the biggest animals on Earth.

A spectacular fossil graveyard reveals a 43-million-year-old whale that had four legs and could walk.

A spectacular fossil graveyard reveals a 43-million-year-old whale that had four legs and could walk.

A spectacular fossil graveyard reveals a 43-million-year-old whale that had four legs and could walk.

A spectacular fossil graveyard reveals a 43-million-year-old whale that had four legs and could walk.

A spectacular fossil graveyard reveals a 43-million-year-old whale that had four legs and could walk.

A spectacular fossil graveyard reveals a 43-million-year-old whale that had four legs and could walk.

Around our solar system, violent eruptions are shaping distant worlds.

Sixty-six million years ago, an asteroid wiped out the dinosaurs in a fiery global catastrophe.

Sixty-six million years ago, an asteroid wiped out the dinosaurs in a fiery global catastrophe.

Sixty-six million years ago, an asteroid wiped out the dinosaurs in a fiery global catastrophe.

Sixty-six million years ago, an asteroid wiped out the dinosaurs in a fiery global catastrophe.

Sixty-six million years ago, an asteroid wiped out the dinosaurs in a fiery global catastrophe.

Sixty-six million years ago, an asteroid wiped out the dinosaurs in a fiery global catastrophe.

Sixty-six million years ago, an asteroid wiped out the dinosaurs in a fiery global catastrophe.

Sixty-six million years ago, an asteroid wiped out the dinosaurs in a fiery global catastrophe.

Sixty-six million years ago, an asteroid wiped out the dinosaurs in a fiery global catastrophe.

Sixty-six million years ago, an asteroid wiped out the dinosaurs in a fiery global catastrophe.

Out in the solar system, ice can get bizarre. Visit strange, frozen worlds - from Uranus's ultra-hot superionic ice, to glaciers of nitrogen ice on Pluto, to carbon dioxide snow on Mars - and discover why the ice here on Earth is so unique.

The ancient Maya built large complex cities with towering pyramids and temples that served as centers for a thriving civilization.

The ancient Maya built large complex cities with towering pyramids and temples that served as centers for a thriving civilization.

The ancient Maya built large complex cities with towering pyramids and temples that served as centers for a thriving civilization.

The ancient Maya built large complex cities with towering pyramids and temples that served as centers for a thriving civilization.

The ancient Maya built large complex cities with towering pyramids and temples that served as centers for a thriving civilization.

The ancient Maya built large complex cities with towering pyramids and temples that served as centers for a thriving civilization.

The ancient Maya built large complex cities with towering pyramids and temples that served as centers for a thriving civilization.

The ancient Maya built large complex cities with towering pyramids and temples that served as centers for a thriving civilization.

From meteorites that impact Earth, to a moon that orbits backwards, to an imposter lurking in the asteroid belt, a variety of strange, wandering worlds are rewriting what we know - and even how we think about - our solar system.

Recent discoveries in archaeology are exploding the myth of the Amazon as a primeval wilderness, revealing traces of ancient civilizations that flourished for centuries, with prehistoric populations numbering in the millions.

Recent discoveries in archaeology are exploding the myth of the Amazon as a primeval wilderness, revealing traces of ancient civilizations that flourished for centuries, with prehistoric populations numbering in the millions.

Recent discoveries in archaeology are exploding the myth of the Amazon as a primeval wilderness, revealing traces of ancient civilizations that flourished for centuries, with prehistoric populations numbering in the millions.

During restoration work after the devastating 2019 fire at Notre Dame de Paris, two lead sarcophaguses were discovered under the cathedral's stone floor.

During restoration work after the devastating 2019 fire at Notre Dame de Paris, two lead sarcophaguses were discovered under the cathedral's stone floor.

During restoration work after the devastating 2019 fire at Notre Dame de Paris, two lead sarcophaguses were discovered under the cathedral's stone floor.

During restoration work after the devastating 2019 fire at Notre Dame de Paris, two lead sarcophaguses were discovered under the cathedral's stone floor.

During restoration work after the devastating 2019 fire at Notre Dame de Paris, two lead sarcophaguses were discovered under the cathedral's stone floor.

During restoration work after the devastating 2019 fire at Notre Dame de Paris, two lead sarcophaguses were discovered under the cathedral's stone floor.

During restoration work after the devastating 2019 fire at Notre Dame de Paris, two lead sarcophaguses were discovered under the cathedral's stone floor.

During restoration work after the devastating 2019 fire at Notre Dame de Paris, two lead sarcophaguses were discovered under the cathedral's stone floor.

During restoration work after the devastating 2019 fire at Notre Dame de Paris, two lead sarcophaguses were discovered under the cathedral's stone floor.

Explore the revolutionary engineering behind Paris's iconic landmark.