Solar Terrarium was a planet located in the Solar Terrarium system.
It orbited a sun that for years provided a great deal of heat for the natives, who needed a constant temperature of 140 degrees in order to live comfortably. But due to years of pollution, the atmosphere became flooded with clouds of smoke, which blocked off much of the heat of the sun, making it unbearably cold for the natives, who sought after Earth as a possible planet for them to terraform and colonize.
However Earthlings couldn't survive in that kind of heat, which led the Super Friends to stop Kolbar, a native of the planet, from causing Earth to fall closer to the Sun.
In the aftermath of this Cosmic Crisis, a few members of the Super Friends traveled to Solar Terrarium to clean up the atmosphere, thus making it suitable for their species once more.