The Planet Argo (DC Animated Universe)

"Five years ago, Argo was a thriving, vibrant world. But then, without warning, our sister planet, Krypton, was destroyed in a giant chain of explosions. Krypton's destruction tore Argo from its orbit."
— Kala In-Ze
Argo was a sister planet of Krypton, orbiting Rao.
== History ==
As the smaller neighbor planet of Krypton, Argo was a thriving, vibrant world to the Argoans. But when Krypton exploded, Argo was torn from its orbit. Its landscape was devastated by shock waves, earthquakes, and super tidal waves. After these cataclysmic events, Argo began to slowly freeze from being too far from its sun, causing the deaths of nearly all the world's inhabitants, and leaving few survivors. The remaining Argoans sent distress calls into space, but they were never answered.
Kala In-Ze, Argo's chief physician, placed herself and her family in cryonic stasis, in the hopes that they would survive until help came. Over time, ice gradually encroached on the cryonic cells, destroying all except the one holding Kala's teenaged daughter, Kara In-Ze.
Years later, Superman arrived in the star system in hopes of finding any survivors. He intercepted a distress signal, and traced it to the now frozen planet. It was a holographic message left behind by Kala In-Ze, as well as the cryonic tubes. He took the sole survivor, Kara, home with him.
During its final years as a habitable world, Argo was of a similar technological level to Earth in the 30th century.