Hopefully you are not home-schooled OP!

Alrighty, time to anonymously spam her e-mail with zoomed in pictures of the moon accompanied by scientific explanations... and pray you got your wit from your dad's side..

Show her proof and correct her so she doesn't make that mistake in public or teach other the wrong thing.

Good thing she isn't your teacher ? Looks like education has taken a large step from when she was in school.

Maybe she's onto something here...

And this is the person who has control over your adolescent life... It's a scary thing

Google.

Maybe your mom knows something we don't

my friends grandma didn't know Britain was an island...

Wow that's just wow