National Moon Day: Facts You Should Know On The 47th Anniversary Of The Apollo 11

July 20 marks the 47^th anniversary of Neil Armstrong's and Buzz Aldrin's moon landing - with a video of both astronauts walking on the satellite beaming back to earth, and Armstrong uttering the famous words:

"One small step for man, one giant leap for mankind."

#OnThisDay 1969 first manned moon landing Apollo 11 "Houston, Tranquility Base here. The Eagle has landed" #Apollo11 pic.twitter.com/qBFGURgfcE

— WatkinsMarine (@WatkinsMarine) July 20, 2016

However, despite such words, and despite first-hand accounts from Armstrong and Aldrin themselves, many conspiracy theorists still believe that the landing did not actually happen. Mirror UK said that these people believed the footage was a recording from somewhere on Earth, proof being that the flag they planted on the surface of the satellite was waving in the air - and there is no wind on the moon.

Still, whether or not you believe in the moon landing, a lot of people are certainly remembering the day, and here are some facts that you should know about one of the biggest events in human history:

21 hours

Both astronauts spent a few hours walking on the moon and collecting samples - National Geographic noted that they logged in a total of 21 hours on the moon - many of it spent trying to sleep in the frigid lander before they lifted off for a rendezvous with the Columbia for their return voyage.

Things left behind

What few know is that Armstrong and Aldrin also left things on the moon before leaving. History Extra noted that the things that they left behind included a lot of used equipment; the American Flag, an Apollo 1 patch for the first crew that died in training; commemorative medallions as a nod for Yuri Gagarin (the first man in space) and Bladimir Komarov; and a gold pin the shape of an olive branch as a symbol of peace.

Wet ashes and gunpowder

The moon may look lovely, but it's not really magical. When the astronauts removed their space suits upon their return on earth, they were met with terrible smells - the moon dust gathered on their boots and gave a stench when it made contact with oxygen. Armstrong said it smelled like wet ashes in a fireplace, whole Aldrin noted it smelled like "spent gunpowder."