APOD: The Horsehead Nebula (2013 Dec 31)

[APOD Robot]

The Horsehead Nebula

Explanation: The Horsehead Nebula is one of the most famous nebulae on the sky. It is visible as the dark indentation to the red emission nebula in the center of the above photograph. The horse-head feature is dark because it is really an opaque dust cloud that lies in front of the bright red emission nebula. Like clouds in Earth's atmosphere, this cosmic cloud has assumed a recognizable shape by chance. After many thousands of years, the internal motions of the cloud will alter its appearance. The emission nebula's red color is caused by electrons recombining with protons to form hydrogen atoms. Also visible at the bottom left of the picture is a greenish reflection nebulae that preferentially reflects the blue light from nearby stars.

<< Previous APOD

This Day in APOD

Next APOD >>

[/b]

[Boomer12k]

Always a pleasure....

The vertical streams remind me of Aurora....only red....


:---[===] *

[biddie67]

It seems to me that the horse head in this cloud has already become less distinct than the first pictures that I saw of it years ago.

[Jim Armstrong]

Thanks for another year of APOD's and Happy New Year.
It would be more in the tradition of avoiding assumptions if the text here read: "...assumed a recognizable shape presumably by chance."

[Chris Peterson]

It seems to me that the horse head in this cloud has already become less distinct than the first pictures that I saw of it years ago.

Most likely just a consequence of changing imaging technology. Dust nebulas don't evolve rapidly. I doubt there has been any obvious visual change in the Horsehead over a few decades.

[C0ppert0p]

The "Man Playing a Flute" nebula, just off to the left of the Horse Head nebula, would be just as well know, if it were bigger

[BDanielMayfield]

The "Man Playing a Flute" nebula, just off to the left of the Horse Head nebula, would be just as well know, if it were bigger

I like that, and it demonstrates a fractal nature to these interstellar cloud formations.

[Ann]

The "Man Playing a Flute" nebula, just off to the left of the Horse Head nebula, would be just as well know, if it were bigger

I like that, and it demonstrates a fractal nature to these interstellar cloud formations.

I like it too, and indeed, it demonstrates the fractal nature of cloud formations!

But the man playing the flute wasn't big enough for Williamina Fleming to discover him!

Ann

[Beyond]

Not much discussion or horsing around, this time around with the Horsehead Nebula, sooo... i think I'll post my infrapink version again.

1365980983.jpg