10. Water
https://www.bbc.co.uk/news/science-environment-13545848

9.  Strange Thickness Anomaly
https://moon.nasa.gov/about/what-is-inside-the-moon/

8.  Another Planet
https://www.space.com/25322-moon-formation-wild-theories.html

7. Layers
http://www.classzone.com/vpg_ebooks/ml_sci_gr8/accessibility/ml_sci_gr8/page_394.pdf

6.  Alien Materials
https://www.nhm.ac.uk/discover/how-did-the-moon-form.html

5.  Iron
https://www.space.com/19582-moon-composition.html

4.  Tunnels
https://en.wikipedia.org/wiki/Geology_of_the_Moon#Lunar_lava_tubes

3. Earth's Origin
https://www.space.com/25322-moon-formation-wild-theories.html

2.  Unexplained Mass
https://nerdist.com/article/theres-something-mysterious-hidden-inside-the-moon/

1. A Spaceship
https://en.wikipedia.org/wiki/Hollow_Moon