Discover the cosmosEach day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.
What causes unusual knots of gas and dust inplanetary nebulas?
Seen also in the Ring Nebula, the Dumbbell NebulaandNGC 2392, the knots’ existence was not initially predicted, and their origins are stillnot well understood.
Picturedhereis a fascinating image ofpartof the Helix Nebulaby the James Webb Space Telescopeshowing tremendous detail ininfrared light.
The cometary knots have masses similar to the Earthbut have sizes typically several times the orbit of Pluto.One hypothesisfor the fragmentation and evolution of the knots includes existing gas beingdriven outby a less dense but highly energeticstellar windof the central evolving star.
TheHelix Nebulais one of the closest examples of aplanetary nebulacreated at the end of thelife of a Sun-like star.
Given a technical designation of NGC 7293, the Helix Nebulalies about 650light-years away towards the constellation of Water Carrier.