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Note: X and Y are coordinates (light years on XY plane) relative to Terra at (0, 0)

System Information
X:Y Coordinates -462.868 : 226.327[e]
Star names Ptolemy-A, Ptolemy-B
Spectral class A1V (Ptolemy-A) plus unspecified white dwarf (Ptolemy-B)[1]
Recharge time 162 hours[1]
Recharge station(s) None[1]
Planets 4+ (Ptolemy-A)

The Rosetta system, named after its inhabited body in accordance with BattleTech convention,[2] is technically the Ptolemy binary star system. It includes at least four planets around Ptolemy-A, the fourth being the super-jovian gas giant Champollion which in turn possesses thirteen moons, one of them the eponymous inhabited moon Rosetta.

System Description[edit]

System History[edit]

Political Affiliation[edit]



Orbital view
Orbital view
System position moon around 4th planet[1]
Jump point
47.06 days[1]
Moons None[1]
Surface gravity 0.89[1]
Atmospheric pressure Standard (Breathable)[1]
Equatorial temperature 29°C (Arid)[1]
Surface water 70%[1]
Highest native life None[1]
Reference Year 3028[1]
Capital Young[1]
Population 12,150,000[1]
Socio-Industrial Levels D-C-B-D-B[1]
HPG (Representative) None[1]

Rosetta is a moon of the gas giant Champollion (one out of thirteen). It was terraformed by the Rim Worlds Republic for easier access to its mineral resources.

Champollion is a planet of the binary system's primary star, the A1V-class Ptolemy-A. Every 50 years the white dwarf Ptolemy-B makes close passes to Ptolemy-A, and Rosetta is known to have increased periods of tectonic and volcanic activity during every third pass when Ptolemy-B also approaches Champollion closer, causing tidal interactions on Rosetta. During these times Rosetta's plains are flooded with molten sulfur.[1]

When the first such sulfur flooding happened (implicitly, in 2728) after the moon was colonized, the colonists were well-prepared, but when it occurred for the second time (implicitly in 2878), there was no Rim Worlds Republic or Star League anymore and the Succession Wars era with its lostech problem was in full swing. The colony that had 14 million citizens at its peak was devastated. Since then, the remaining colonists have moved to less endangered areas, far from Rosetta's nearside to Champollion.[1]

In 3028 a Star League era cache of Starfire Head-hunter missiles was found on Rosetta, but the recovery operation by elements of Hansen's Roughriders ran afoul of resistance from local forces defending the site. The sulfur flooding set in before the missiles could be recovered and completely covered the bunker beyond hope of reaching it, though evidence suggests that the local hovertanks may have used Starfire missiles against the Roughriders.[17]

Planetary History[edit]

Planetary Rulers[edit]

Rosetta is ruled by a council, but over the years was occasionally taken over by pirates using it as a strike base.[1]

Military Deployment[edit]


Planetary Locations[edit]

Nearby Systems[edit]

Systems within 60 light-years (distance in light years)
Closest systems first:
Slewis 22.21 Caldarium 26.26 Kerman 28.78 Cilvituk 31.21
Langhorne 35.97 Sialkot 36.17 Zefri 39.52 Synsstad 41.68
Seven Lands 41.79 Sidon 44.71 Farcry 44.87 Marisura 46.41
Bougie 53.78 Mahrah 56.40 Ormstown 56.75 Beauvais 59.61


  1. 1.00 1.01 1.02 1.03 1.04 1.05 1.06 1.07 1.08 1.09 1.10 1.11 1.12 1.13 1.14 1.15 1.16 1.17 1.18 1.19 BattleTech: 25 Years of Art & Fiction, p. 47, "Rosetta Planet Profile"
  2. Explicitly spelled out thusly in the "Rosetta" sidebox, BattleTech: 25 Years of Art & Fiction, p. 47
  3. Handbook: Major Periphery States, p. 18, "Rim Worlds Republic after Age of War - [2571] Map"
  4. Handbook: House Steiner, p. 25, "Lyran Commonwealth after Age of War - [2571] Map"
  5. Historical: Reunification War, p. 158, "Inner Sphere - [2596] Map"
  6. Handbook: Major Periphery States, p. 25, "Rim Worlds Republic At the Fall of the Star League - [2750] Map"
  7. Era Report: 2750, p. 36, "Inner Sphere - [2750] Map"
  8. Field Manual: SLDF, p. vii, "Inner Sphere - [2764] Map"
  9. Historical: Liberation of Terra Volume 1, p. 10, "Inner Sphere - [2765] Map"
  10. Field Report 2765: Periphery, p. 38, "Rim Worlds Army Deployment Map - [2765]"
  11. Historical: Liberation of Terra Volume 1, p. 104, "Rim Worlds Republic - [2767] Map"
  12. Handbook: House Steiner, p. 36, "Lyran Commonwealth after First Succession War - [2822] Map"
  13. Historical: Liberation of Terra Volume 2, p. 122-123, "Inner Sphere - [2822] Map"
  14. Handbook: House Steiner, p. 40, "Lyran Commonwealth after Second Succession War - [2822] Map"
  15. House Steiner (The Lyran Commonwealth), p. vii, "Lyran Commonwealth Map - [3025]"
  16. Handbook: House Steiner, p. 47, "Lyran Commonwealth after Third Succession War - [3025] Map"
  17. 17.0 17.1 Starfire (in: 25 Years of Art and Fiction, pp. 47-57)
  18. Handbook: House Steiner, p. 56, "Lyran Commonwealth after Fourth Succession War - [3030] Map"
  19. Handbook: House Steiner, p. 59, "Lyran Commonwealth after War of 3039 - [3040] Map"
  20. Historical: War of 3039, p. 132, "Inner Sphere - [3040]"
  21. Era Report: 3052, p. 10, Inner Sphere [3050] Map
  22. Handbook: House Steiner, p. 61, "Lyran Commonwealth after Clan Invasion - [3052] Map"
  23. Era Report: 3052, p. 22, Inner Sphere [3052] Map
  24. Era Report: 3062, p. 10, Inner Sphere - [3057] Map
  25. Era Report: 3062, p. 29, "Inner Sphere - [3063] Map"
  26. Handbook: House Steiner, p. 70, "Lyran Commonwealth after FedCom Civil War - [3067] Nao"
  27. Jihad: Final Reckoning, p. 42, "Inner Sphere - [3067] Map"
  28. Jihad Secrets: The Blake Documents, p. 64, "Inner Sphere - [3075] Map"
  29. Field Report: LAAF, p. 19, "Lyran Alliance Armed Forces Deployment Table - [August 3079]"
  30. Jihad: Final Reckoning, p. 62, "Inner Sphere - [3081] Map"
  31. Field Manual: 3085, p. vii, "Inner Sphere - [3085] Map"
  32. Map of the Inner Sphere 3130
  33. Era Report: 3145, p. 11, "Inner Sphere - [3135] Map"
  34. Era Report: 3145, p. 39, "Inner Sphere - [3145] Map"
  35. Field Manual: 3145, p. VI, "Inner Sphere - [3145] Map"