The Heart of the ForceThe Heart of the Force, also known as the Heart of Eternity, was a wound in the Force located on the planet Lehon. It was the site of a thought bomb detonated thousands of years in the past. The Heart of the Force appeared as a sphere of dark side energy in which the souls of its many hundreds, if not thousands, of victims had been trapped.
History
The existence of the Heart of the Force was first discovered from the Holocron of Antar IV in the early days of the Brotherhood after the holocron was recovered in 15 ABY from Antar IV by the Night Hawks under the command of Trevarus Caerick. Given the holocron was created during the days of Darth Revan and Darth Malak, it is assumed the thought bomb must have predated the Jedi Civil War which ended in 3,956 BBY.
However, the Holocron of Antar IV was cryptic as to the whereabouts of the Heart of the Force. Trevarus Caerick surmised this was the work of the holocron's creator to deliberately hide the location of the planet. It was not until information on the planet Lehon was discovered from the Holocron of Darth Maestus by Darth Vexatus in 27 ABY that it became possible to connect Lehon with the planet referenced in the first holocron.