Image from Wyrmshadow
- Yall-Ull (Gliese 667) - Text by Mark Ryherd,
A triple-star system in the Inner Sphere.
- Yangko - Text by Steve Bowers
Penglaiese heritage world.
- Yanqiu - Text by Steve Bowers
Superterrestrial 'eyeball' world with indigenous xenoecology
- Yathrib - Text by M. Alan Kazlev
Stellar Umma system.
- Yin-Yang (Luhman 16) - Text by M. Alan Kazlev
A pair of young brown dwarf near Solsys, a Nauri system as well as site of one of the first Deeper Covenant colonies and Beamrider Network stations. Currently a prosperous and diverse old core system and beamrider nexus.
- Yoruba - Text by Steve Bowers
Terraformed world with relics of an earlier colonisation by ahuman AI.
- Yosonia - Text by Steve Bowers
HD 180161 Colony founded by the Yoson Confederacy in 2608.
- Ys, The Ocean of - Text by Liam Jones
Artificial circumstellar ocean world.
- Zallach-Whige - Text by Steve Bowers
House Genen colony at Chi Eridani.
- Zamzam - Text by M. Alan Kazlev
Capital of the Shell Stellar Umma.
- Zarathustra - Text by Anders Sandberg
A colony that recovered from near-collapse to become one of the most successful in the Inner Sphere.
- Zarauztar - Text by M. Alan Kazlev
Important NoCoZo system.
- Zavijava (Beta Virginis) - Text by M. Alan Kazlev and Anders Sandberg
An important Inner Sphere region, home to the famous planet Pacifica. Most polities are members of the Virginis Combine and are loosely aligned with the Utopia sphere or Solar Dominion, though they are a diverse group.
- Zennor System - Text by Steve Bowers
Several icy moons of gas giants in this system have been heated to create ocean-worlds or water-worlds.
- Zeta Legati - Text by Anders Sandberg and M. Alan Kazlev
Home to a nanotech upload civilization, the Eternalists, in the Serpens sector of the Outer Volumes.
- Zeta1 Reticuli - Text by Anders Sandberg
A populous system with three successfully terraformed planets.
- Zeta2 Reticuli - Text by Steve Bowers
Diamond Network star with one single AI inhabitant, known as Ziggy.
- Zetap IX - Text by M. Alan Kazlev
Important Metasoft world.
- Zhang Qian - Text by Steve Bowers
Sophic League planet with mobile cities.
- Zhenruj (Mu Herculis) - Text by The Astronomer (2021)
A quaternary system, 27.20 ly from Sol. Part of the pre-Nexus Vega wormhole network.
- Zikhron - Text by Steve Bowers
Originally a Jewish colony, now culturally diverse.
- Zybal Manta - Text by M. Alan Kazlev
Location of the Amacrine Cloud, an important example of transingularity Perfect Art accessible to subsingularity beings.
Text by Orion's Arm Editors
Initially published on 31 December 2007.