An overview of the Chandra mission and goals, Chandra's namesake, top 10 facts.
Classroom activities, printable materials, interactive games & more.
Overview of X-ray Astronomy and X-ray sources: black holes to galaxy clusters.
All Chandra images released to the public listed by date & by category
Current Chandra press releases, status reports, interviews & biographies.
A collection of multimedia, illustrations & animations, a glossary, FAQ & more.
A collection of illustrations, animations and video.
Chandra discoveries in an audio/video format.
Q&A: Normal Stars, White Dwarf Stars, and Star Clusters

Q:
The term "Planetary Nebula" seems misleading. Why are they called that?

A:
Planetary Nebula Mz 3
Planetary Nebula Mz 3
The definition of the term "planetary nebula" is historically correct, but the term is a misnomer. Some planetary nebulas appeared to look like giant planets, specifically Uranus, when viewed through a small telescope by William Herschel, who coined the term. Astronomy is a very old field of study, so historical artifacts like this are not rare.

Planetary nebulas are really shells of gas cast off by evolved, Sun-like stars. The Sun should experience this phase in a few billion years.

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