M42 was one of the first astronomical objects I ever tried to photograph. I attached my Nikon D200 to my 5" Meade Achromat, and took a single unguided 30 second frame at ISO 800. I knew nothing about darks and flats and stacking and such, but I was so proud of that image! Little did I realize what a challenge this object is, just because it's so bright.

This nebula is easily visible to the naked eye, even from within the town where I live. It's hanging down (from my northern vantage point) from Orion's belt, and it is one of the star factories nearest us. A multitude of stars are forming or have formed in this cloud of hydrogen. Four of them form an intensely bright cluster right in the middle of the brightest part of the cloud. The power of the radiation from those four stars has carved a cavity in the cloud. The blister of gas and dust around that cavity has "popped" to expose the fluorescing hydrogen inside.

NGC 1977 is another large star forming region near M42, above it in this image. It has been dubbed "The Running Man Nebula" for the shape of the reddish nebulosity at its center. In fact, this is simply an earlier stage of the same process that shaped M42. The dusty reflection nebula surrounding the interior cavity has just started to dissipate under the pressure of the powerful stars within. As a result, we can peek into its interior, glowing red with Hydrogen Alpha emission.

Photographically, M42 is notoriously difficult to capture. The brightest parts of the nebula are thousands of times brighter than the faintest parts. Multiple exposures of different lengths are required to fully capture the detail over the entire area. These exposures are then combined using a technique called High Dynamic Range (HDR) processing. Many HDR images of this beautiful nebula look pasty and flat. They lack the depth... the glow... that make them truly captivating. I've tried to avoid that with this image, sacrificing some detail contrast for the 'feel' of the brightness difference between the inner, outer, and extended envelope nebulosity.

One of the biggest challenges in the creation of this image involved the geosynchronous satellite band, which runs right through that region of sky. Dozens of satellite trails were present in the combined image, requiring a couple of hours of manual work to remove. Virtually every subframe had at least one satellite streak in it, and a lot of them had several. It's amazing how many geosynchronous satellites are up there.

This 38 megapixel image is my very first attempt at an HDR rendition. I combined exposures of 30 and 240 seconds from the Takahashi CCA250/Apogee Aspen 16M, 10 and 60 seconds from the Planewave CDK17/Apogee Alta 16M, and 10 seconds from the Planewave CDK20/SBIG STT8300M. The 441 subframes combined to create this image required 9.6 hours of imaging over 6 nights from November 7, 2013, to January 23, 2014.

The distance to the Orion Nebula has recently been geometrically determined to be 1,425±61 light years. At that distance, this image is about 58 light years across.

Image acquired at Prairie Sky Observatory and Sugar Grove Observatory, facilities of Twin City Amateur Astronomers (tcaa.us).