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.

2024 September 10
The featured image a starfield that glows gold. On the left
is the dark horsehead nebula, while on the right is the blue-glowing
Orion Nebula.
Please see the explanation for more detailed information.

Horsehead and Orion Nebulas
Image Credit & Copyright: Antoine & Dalia Grelin

Explanation: The dark Horsehead Nebula and the glowing Orion Nebula are contrasting cosmic vistas. Adrift 1,500 light-years away in one of the night sky's most recognizable constellations, they appear in opposite corners of the above stunning mosaic. The familiar Horsehead nebula appears as a dark cloud, a small silhouette notched against the long glow of hydrogen -- here shown in gold -- at the lower left. Alnitak is the easternmost star in Orion's belt and is seen as the bright star to the left of the Horsehead. Just below Alnitak is the Flame Nebula, with clouds of bright emission and dramatic dark dust lanes. The magnificent emission region, the Orion Nebula (aka M42), lies at the upper right. Immediately to its left is a prominent reflection nebula sometimes called the Running Man. Pervasive tendrils of glowing hydrogen gas are easily traced throughout the region.

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Tomorrow's picture: river meets sky


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