T-Rex: It's the 50s! Sputnik has just orbited above the United States and peeps are FREAKING OUT. America wants to win the space race, and comes up with two options. OPTION ONE: create NASA, send men into space. Option 2:

T-Rex: NUKE THE FRIGGIN' MOON.

T-Rex: This plan has a lot of benefits! It's cheap, America already has the missiles and nukes lying around anyway, and a nuclear explosion on the moon WILL be visible from Earth. Plus it'd show those Reds who's boss!
Dromiceiomimus: "My fellow Americans: totally check out the moon tonight, but I can't tell you why because it's a surprise. Also, the hated Soviets should look too."
T-Rex: EXACTLY.

Utahraptor: So what happens next in your alternate history?
T-Rex: "Alternate"? What?

T-Rex: This happened, dude. Project A119. CARL SAGAN worked on it. It only got cancelled when they couldn't guarantee the nuke wouldn't miss and fall back to Earth, and they also got kinda worried that somehow - SOMEHOW - nuking the moon would not be the PR coup they'd hoped.
Utahraptor: The 20th century, huh?

Narrator: THE 20TH CENTURY, PERSONIFIED:
T-Rex: Hi, I represent the 20th century! In the space of almost 50 years we invented planes, TV, helicopters, digital computers, nukes AND spaceships!
T-Rex: So YEAH
T-Rex: WE WENT A LITTLE CRAZY