The Skirmish on Ganymede was a short battle which took place in early April 2260 between the Army of Light led by both John Sheridan and Delenn and a rogue Shadow vessel in orbit around Jupiter. Working with the Rangers, Michael Garibaldi arranged for a former member of IPX, Dr. Mary Kirkish, to come aboard Babylon 5. Dr. Kirkish told the Army of Light about a Shadow vessel that was found on Mars in 2253. The ship was recovered by another Shadow vessel and Kirkish was reassigned, ordered not to say anything to anyone about what she had seen. Another ship was discovered on Ganymede just prior to the battle, which Earthforce was planning on reactivating within a week. After making arrangements for Kirkish to go to Minbari space, Delenn and Sheridan formed a plan to destroy the Shadow vessel