What are the two versions of Earth in the novel, Across the Universe?

There are two versions of Earth mentioned in the story. One is Sol-Earth, which is the earth that is known to the reader. However, Sol-Earth has changed drastically. NASA discovered an inhabitable planet some 300 years away and decided that it could be inhabited - more successfully - than the current earth. The current earth struggles with environmental issues and many other problems that could be solved on a new planet. The new planet would allow select leaders to seek out new and untapped natural resources. The top military people and scientists capable of making it happen are cryo frozen to create this new future. Amy Martin's parents are top personnel and have been chosen to go into space. Amy goes along as "non-essential" cargo.

Centauri-Earth is the destination for Godspeed. Not much is known about Centauri-Earth, save for its location. The model of Centauri-Earth that resides in Recorder Hall is almost a blank canvas. Eldest and the other officials on the ship prepare for all possible conditions on Centauri-Earth since it is impossible to gauge anything about the planet until Godspeed arrives.