Praxis (alternate reality)
Praxis was a natural moon of the Klingon homeworld, Qo'noS. It was the only moon of that planet and was inhabited. ( display graphic)

In the alternate reality, Praxis was destroyed by an unknown catastrophic event prior to 2259 and was left severely fragmented as a result. ( display graphic )

Appendices

Background information

In , the Enterprise journeys to Qo'noS, and a large moon fragment strongly resembling the remains of Praxis, as depicted in Star Trek VI, can be seen. Co-writer Alex Kurtzman stated, "It certainly was inspired by Praxis, however, it's not specified, so we're leaving it open as to exactly what that moon was."  Roberto Orci agreed in a comment on Twitter, stating that the moon was "not specified as Paraxis [sic]. But could be."  This destroyed sole moon of Qo'noS is, however, identified as Praxis on screen, in a table of information. 

Background materials for Star Trek Into Darkness also mention Section 31 having a mysterious "Praxxis [sic] Project", which may or may not have anything to do with the moon. (See here and here).

Apocrypha
The ization of , confirms that the broken moon orbiting Qo'noS was Praxis. 

The  prequel Star Trek: Khan revealed that the moon was destroyed as the result of a mission undertaken by John Harrison for Section 31 (who learns his true identity as Khan while on said mission).

External link

Moons
Locations (alternate reality)