The Orion Arm, or Orion–Cygnus Arm, is a minor spiral arm of the Milky Waygalaxy.[2] It is of interest because the Solar System (including the Earth) is inside it. The spiral arm is some 3,500 light-years (1,100 parsecs) across and approximately 10,000 light-years (3,100 parsecs) in length.[3]
The Orion Arm is between the Carina–Sagittarius Arm (toward the Galactic centre) and the Perseus Arm (toward the outside Universe). The Perseus Arm is one of the two major arms of the Milky Way. The Solar system is on the Orion spur, between the two longer adjacent arms Perseus and Carina-Sagittarius.[4]
Inside the Orion Arm, the Solar System is close to the inner rim, in the Local Bubble. It is about halfway along the Orion Arm's length, about 8,000 parsecs (26,000 light-years) from the Galactic centre.