Mass Effect Planetary Database: Location Details
Theyar Theyar

Cluster: Argos Rho
System: Hydra
Orbital Period: 12.8 Earth Years
Radius: 60774 km
Day Length: 11.8 Earth Hours

Theyar is a large gas giant with traces of chlorine and sodium in its atmosphere. It also has a significant amount of water vapor in the clouds of its upper atmosphere.

Theyar was struck by an asteroid at least 12 kilometers in diameter within the last hundred years. The superheating caused by the impactor's atmospheric passage created a large bank of vicious storms along the equatorial band.