Early Earth was very inhospitable
This exhibit was created by the students in ASTR202 at the University of AZ. The main exhibit is the walking tour history of the universe (the image here is from just after the begining). It is a spiral with exhibits for major events in the history of the Earth spaced appropriately for when they occur. Along the way there are teleporters to take you to more detailed exhibits for some events.
Also on display is an outline put together by the instructors on their experience with this. This may be especally useful for people considering SL class projects.