APOD: August 4, 2026 – Curious Cometary Knots in the Helix Nebula

APOD

Science
APOD
APOD: August 4, 2026 –…

Today’s APOD
Archive
Submissions
Index
Search
Calendar
RSS
Education
About
Discuss

APOD
Astronomy Picture of the Day

Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.

Curious Cometary Knots in the Helix Nebula

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. Pictured here is a fascinating image of part of the Helix Nebula by the James Webb Space Telescope showing tremendous detail in infrared light. The cometary knots have masses similar to the Earth but have sizes typically several times the orbit of Pluto. One hypothesis for the fragmentation and evolution of the knots includes existing gas being driven out by a less dense but highly energetic stellar wind of the central evolving star. The Helix Nebula is one of the closest examples of a planetary nebula created at the end of the life of a Sun-like star. Given a technical designation of NGC 7293, the Helix Nebula lies about 650 light-years away towards the constellation of Water Carrier (Aquarius).

Date

August 4, 2026

Credit

Image: NASA, ESA, CSA, STScI; Image Processing: Alyssa Pagan (STScI)

Authors & editors:

Robert Nemiroff, Jerry Bonnell, Cecilia Chirenti, Keighley Rockcliffe

A service of:

ASD at NASA / GSFC,NASA Science Activation & Michigan Tech. U.

Random APOD Generator

Yesterday’s Image

APOD: 2026 August 3 – Vaporizing Meteor Photobombs the Lacerta Nebula

Tomorrow’s Image