The why is something that we will probably never know.

So, either NASA is lying, or the size of North America changes over time.

Now, psychopaths lie. Many seem to be unable to tell the truth.

NASA was started by THE dark occultists. And to occult is to hide.
And that is what they did.

If they have knowledge and you think you have knowledge than who is the more powerful?

Further, you will find the same organization occulting all kinds of knowledge and changing history books, science books and actually hiding artifacts.

Look into Cecil Rhodes (of the Rhodes Scholarship) for some horrifying deep conspiracy stuff.