When the Apollo 11 mission entered space and Neil Armstrong took the first steps on the moon on July 20, 1969, there were a lot of things about Earth’s only natural satellite that we didn’t know. The moon landing certainly helped to explain a lot of the questions that were burning in the minds of scientists, but also illuminated some weird facts about the moon. The lead-up to the launch even caused some strange occurrences.

It’s been over 50 years since the Apollo 11 mission landed humans on the moon, and in that time, we’ve learned a lot more about what happened during that historic event. Here are five facts that you may not have known about that historic mission that began on July 16, 1969:

1. Scientists were scared of space germs

Following their arrival from the moon on July 27, 1969, Apollo 11 astronauts Neil Armstrong, Buzz Aldrin and Michael Collins were forced to quarantine for over two weeks in case they had returned with any dangerous lunar microorganisms.

Immediately after returning to Earth, the astronauts were transferred into a modified Airstream trailer with a physician and a technician. The “Mobile Quarantine Facility” was transported from the USS Hornet to Pearl Harbor. It was then loaded onto a military transport aircraft and flown from Hawaii to Houston.

The astronauts spent the remainder of their quarantine in the NASA Lunar Receiving Laboratory at Johnson Space Center.

On Aug. 10, 21 days after landing on the moon, Armstrong, Aldrin, and Collins stepped out of quarantine to a room full of reporters.

2. Astronauts trained by walking “sideways”

he majority of the nation stood behind this endeavor, but not everyone was excited about the decision to spend millions of dollars to send a handful of people to the moon. In fact, a group of activists gathered outside the Kennedy Space Center to protest the event. With them, they brought two mules and a wooden wagon to demonstrate the contrast between the state-of-the-art rocket ship against those who couldn’t afford to eat.

Thomas O. Paine, a NASA administrator, spoke with the protestors. His hope was that the civil rights leader, Ralph Abernathy, would “hitch his wagons to our rocket, using the space program as a spur to the nation to tackle problems boldly in other areas, using NASA’s space successes as a yardstick by which progress in other areas should be measured.” After some long chats with Abernathy, Paine was able to convince the group to stop protesting and arranged for them to have a VIP viewing area to watch the launch. Paine must have been pretty convincing, because Abernathy and the group even prayed for the astronauts, saying that they were as proud as anyone of the accomplishment being achieved.

3. The crew was afraid of being locked out of the lunar module

After Armstrong made his first steps on the moon, Aldrin was cautious as he exited the lunar module. He was concerned that the lander would automatically pressurize if the door was latched. Because the hatch opened inward, the pressure inside the lunar module would have made it impossible to open from the outside.

“I then got in position to come down .. came down the ladder, and jumped off, being careful not to lock the door behind me,” Aldrin recounted in a Reuters interview.

4. President John F. Kennedy wasn’t interested in space

In public, President John F. Kennedy told the world that the US would “set sail on this new sea because there is new knowledge to be gained, and new rights to be won, and they must be won and used for the progress of all people.” In reality, JFK didn’t really care about space. Secret tapes revealed that in private, his motivation was primarily just to beat the enemy.

The space race took place during the Cold War, and as such, JFK was less worried about actually landing on the moon than he was about asserting US dominance over the Soviet Union. The Soviets had already beaten the US in making it to space, and Kennedy was desperate to figure out a way to show the US could one-up the Soviets.

He turned to Vice President Lyndon B. Johnson, who had been interested in the space race early on. Johnson had previously said, “control of space means control of the world,” so it is no surprise that his first suggestion to JFK was to land an American on the moon.

5. Moon dirt smells

That’s probably not something you’ve ever even thought about. But it’s true. When Armstrong and Aldrin set foot on the moon, they weren’t sure what kind of terrain they were going to land on. It was unexplored terrain. Turns out, it was solid like a rock, and the two astronauts gathered moon rock and soil samples to analyze. While walking around the moon, dirt clung to their suits that followed them back inside the spacecraft.

When they repressurized the lunar module, the astronauts came to the realization that moon dirt has a particular smell. It gives off an odor similar to fireplace ashes or the air following a fireworks show. It smelt like burnt gunpowder. Unfortunately, scientists back here on Earth never got the chance to take a whiff of moon dirt, because by the time the samples made it all the way back to the labs, they no longer carried their odor.

Charles Fishman, author of One Giant Leap, summed it up perfectly when he wrote, “The smell of the moon remained on the moon.”

6. Astronaut life insurance

Because of the risk involved with spaceflight, the three astronauts devised a clever way to provide for their families in case they didn’t return —autographs.

In the weeks leading up to liftoff, the astronauts signed as many autographs as they could in every spare moment, according to NPR. The astronauts signed hundreds of envelopes to be later postmarked and distributed to their families.

“If they did not return from the moon, their families could sell them — to not just fund their day-to-day lives, but also fund their kids’ college education and other life needs,” space historian Robert Pearlman told NPR.