Water changes forms through temperature change as it goes through the water cycle. It evaporates by being heated by the sun, it condenses by cooling as it reaches higher altitude. It precipitates when the cooled water becomes heavy, and the cycle starts all over again.
Formation of Earth and our Solar system
Some of the challenges are:
Finding out what the characters carved/written on the papyrus are because the papyrus is so weathered and roughed up.
Then actually deciphering the characters was another challenge.
You basically had to have an idea of what the characters meant ^^
