VIDEO: First 3-D Fly-Through of a Supernova Remnant

Victoria Jaggard in Long Beach, California
for National Geographic News

January 7, 2009

Imaging techniques commonly used to peer inside living humans are giving scientists this unprecedented tour of an iconic dead star.

Seen from Earth, the wispy form of Cassiopeia A—the remnant of a massive star that exploded about 330 years ago—looks like a colorful puffball (see picture).

But the new 3-D model, created with data from the Chandra X-Ray Observatory, is allowing astronomers to virtually fly though the supernova remnant and see that it is made of two distinct parts: a spherical blast wave and a flattened inner region.

Scientists now think Cassiopeia A formed when the core of a massive dying star began to collapse, creating a swirling disk of material around it.

The final core collapse caused an explosion that blew lighter elements in all directions, but heavier material in the disk flew outward along the flat plane of the blast wave to create the squashed inner region.

The findings represent "exactly what we had hoped would come" out of the new 3-D technique, according to scientists who unveiled the new model Tuesday at an American Astronomical Society conference in Long Beach, California.