Astronomy Picture of the Day ·

Curious Cometary Knots in the Helix Nebula

The Astronomy Picture of the Day for April 13, 2008 is “Curious Cometary Knots in the Helix Nebula,” an image. It is credited to Credit: C. R. O’Dell and K. Handron ( Rice University ), NASA. The original explanation runs about 159 words.

Curious Cometary Knots in the Helix Nebula
Credit: C. R. O’Dell and K. Handron ( Rice University ), NASA Shown from science.nasa.gov. Not hosted by OpenOrbit.

From the explanation

“What causes unusual knots of gas and dust in planetary nebulas ? Seen also in the Ring Nebula , the Dumbbell Nebula and NGC 2392 , the knots’ existence was not initially predicted and their origins are still not well understood.”

— APOD editors, April 13, 2008

Read the full explanation on science.nasa.gov

At a glance

Date
April 13, 2008
Type
Image
Credit
Credit: C. R. O’Dell and K. Handron ( Rice University ), NASA
Copyright
No copyright notice on the entry. Check the credited institution’s own usage rules before reusing it.
Explanation length
About 159 words

All of April 2008 → · 2008 by month → · Full archive since 1995 →

Topics in this entry

Nebulae

Topics are matched from words in the title and explanation.

On this day: April 13 in other years

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Source

Copy taken Oct 28, 2026, 2:39 AM EDT. The image and explanation belong to their creators. OpenOrbit is not affiliated with or endorsed by NASA.