Orion Arm

The Orion Arm of the Milky Way Galaxy and the Sagittarius arm, which is the next arm “inward.” Earth, and most of known space, lies near the edge of the Orion arm close to the other sections of the galaxy.



The Orion Arm is a minor spiral arm of the Milky Way galaxy some 3,500 light years across and approximately 10,000 light years in length. The Solar System and Earth are within the Orion Arm. It is also referred to as the Local Arm, the Local Spur or the Orion Spur.

The Orion Arm is named for its proximity to the stars in the Orion constellation. It is located between the Sagittarius Arm and the Perseus Arm, two of the four major arms of the Milky Way. Within the Orion Arm, the solar system and Earth are located close to the inner rim in the Local Bubble, about half-way along the Arm's length, approximately 8,000 parsecs (26,000 light-years) from the galactic center.

Messier objects
The Orion arm contains a number of Messier objects:
 * The Butterfly Cluster (M6)
 * The Ptolemy Cluster (M7)
 * Open Cluster M23
 * Open Cluster M25
 * The Dumbbell Nebula (M27)
 * Open Cluster M29
 * Open Cluster M34
 * Open Cluster M35
 * Open Cluster M39
 * Winnecke 4 (M40)
 * Open Cluster M41
 * The Orion Nebula (M42)
 * The De Mairan's Nebula
 * The Beehive Cluster (M44)
 * The Pleiades (M45)
 * Open Cluster M46
 * Open Cluster M47
 * Open Cluster M48
 * Open Cluster M50
 * The Ring Nebula (M57)
 * Open Cluster M67
 * M73
 * The Little Dumbbell Nebula (M76)
 * Diffuse Nebula M78
 * Open Cluster M93
 * The Owl Nebula (M97)