The Sun is on the inner edge of one of the
Milky Way's outer spiral arms. Orion is further away from the galactic centre
still and deeper inside our arm of the galaxy - the Orion Arm.
Galactic spiral arms are regions where gas pressures are high enough to
trigger star formation.
In galaxies, many regions of star formation create many vast gas bubbles.
When the walls of the bubbles meet, new high pressure regions develop
and new episodes of star formation commence. As the cycle continues,
regions of high pressure and associated star formation
move across galactic disks in spiral patterns.
The vast bubble of gas created by the newly formed stars of the sword region
of Orion is helping create the pressure wave that is triggering star formation
in the Milky Way's Orion spiral arm.