M4X-904

"Why would the Ancients put a gate here?" "There's an Ancient right over there. Why not ask him?" "I may be an Ancient, as you call us, but I'm not THAT ancient."

- Richard Woolsey, Ronon Dex and Janus

M4X-904 is a planet in the Pegasus galaxy, which has a Stargate. The planet has a rocky canyon terrain.

History
In 2009, the planet was invaded by the Unknown Aliens.

The planet was briefly visited by Woolsey, Janus, Dr. Elizabeth Weir and Atlantis Reconnaissance 1 on their way to the Stargate hub. Soon after their arrival, the group was attacked by the Aliens. They fled the planet and gated to M4F-788.

Shortly after their departure, Dr. Rodney McKay used the McKay/Zelenka Attero device on the Stargate Network, targeting the Alien's energy signature from their subspace domain. This disintegrated all traces of the Aliens, both in terms of species and in the technology they had brought with them, across the Pegasus galaxies network. This would have wiped out all the Aliens on M4X-904.