Roswell is a city in New Mexico on Earth.
History[]
It is the location of a rumored crash landing of an alien spacecraft in 1947. (SG1: "Thor's Chariot", "Out of Mind", "Prometheus")
When Hathor asked Colonel Jack O'Neill how to contact the Asgard for the purposes of creating an alliance with them, he sarcastically told her to try doing so in Roswell. (SG1: "Out of Mind")
Alternate reality[]
In an alternate reality, the Roswell UFO Incident likewise occurred as Dr. Samantha Carter recognised Jack's reference to the city when he described the Asgard as "Roswell grey." (SG1: "Point of View")
Behind the scenes[]
In the real world, the Roswell incident is widely believed to be a hoax (except by some UFO proponents and conspiracy theorists). It is unknown whether this crash was real in the Stargate universe or also a hoax, although the resemblance of the Asgard to the classic "grey" is uncanny, and the Asgard are known to have monitored Earth at various periods in history.