Asgard is the capital planet of the Yggdrasil System. A small planet with a relatively low gravitational pull, the surface of Asgard is covered in a psychedelic gas. As a result, the humans who colonized the planet were forced to place their settlements in mountainous areas, typically above the clouds.

By most points in the documented timeline, Asgard has been studied extensively by the residents to the point where many of the mysteries have already been unraveled by the governing powers that hold it, which is why much of their efforts are pushed towards investigating the research sites in the other planets of the solar system. Of course, that doesn't stop people from coming to the planet in an attempt to study it's secrets, since these same governments due not make them public.

Asgard contains many remnants of an ancient civilization on it's surface where the gas exists. When the Yggdrasil star is between Asgard and Ymir, Asgard becomes a snow covered world and it's gas takes on a white haze making it hard to study the monoliths, ruins, and other architecture during this time. Additionally, reports have been made that during this time strange beasts not seen in other times walk Asgard's surface, though the descriptions of these beasts may be exaggerated due to the gas' effect. By contrast, when the Yggdrasil star and Ymir star are opposite of one another, Asgard's surface becomes clear and the presence of the psychedelic gas appears to dwindle. This is a deception, and one that has caused more than one soldier to go mad as a result.

Beyond the benefits of research of the mysterious objects on the planet, Asgard has another major reason why it is the capital of the system. The flora and fauna of the planet, coupled with the planet's low gravitational pull, has been noted to have a wondrous effect on the longevity of it's residents. As of present, the number of humans who live on Asgard who have died of age can be counted on one hand, and all of them were old well before they landed on the planet. People living there don't stop aging, but they age incredibly slower - and scientists there have theorized that planet's longevity effects could extend a lifespan to a bare minimum of 1000 years old, assuming no outside forces end it prematurely. At present, the oldest non-supernatural human on Asgard is 157 by the year 4000.