This easter egg has kept many clueless for a long time :)
You can find it at checkpoint 10 where the big loop is located. However, instead of getting a lot of speed there, you should slowly ride up the ramp untill you hear an explosion. Slowly back up and try to land on the red container. This might take some skill to pull off. I found that making a backflip while your front tire is still on the ramp helps. Another way to do this is to go off the loop normally, but face up as you fall, thus collecting the after burner, thus rocketing you back up onto the cargo container, thus revealing an easter egg. Once you are on the container continue to the right to discover this easter egg. Be careful to ride over the barrel as it doesn't have the physics enabled.
InvestigationEditThe image displayed is part of the Voyager Golden Record cover. The Voyager Golden Records are phonograph records which were included aboard both Voyager spacecraft, which were launched in 1977. They contain sounds and images selected to portray the diversity of life and culture on Earth, and are intended for any intelligent extraterrestrial life form, or for future humans, who may find them.
More information can be found by visiting this wiki http://en.wikipedia.org/wiki/Voyager_Golden_Record
The easter egg illustrates the two lowest states of the hydrogen atom.
This section is reserved for Confirmation/comments about this investigation. Investigations will remain open until advised by Redlynx that the final solution for each secret is found.