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Neil Armstrong, the first person to walk on the moon, would have been 89 today. NASA on Monday honored the astronaut, who died in 2012, with a tweet and video remembering the "engineer," "pilot," "teacher" and "American hero." The video includes soundbites, images and videos of Armstrong.

"Neil Armstrong is remembered for many feats, including breaking records in aviation and spaceflight," the tweet reads. "On his birthday, we remember the man who inspired millions when he walked on the surface of the moon."

Neil Armstrong is remembered for many feats, including breaking records in aviation and spaceflight. On his birthday, we remember the man who inspired millions when he walked on the surface of the Moon. More: https://t.co/1y4CX4Zvkq pic.twitter.com/3aup0Q5vqC — NASA (@NASA) August 5, 2019

NASA also shared a post on its site about Armstrong's 39th birthday, which was spent in quarantine following the Apollo 11 moon landing mission in 1969. After the mission, humans, spacecraft and samples had to be in quarantine for 21 days to avoid contaminating the Earth with any lunar micro-organisms.

On that birthday, workers in the Lunar Receiving Laboratory, where Armstrong was in quarantine, made him a cake and threw a surprise party. Armstrong enthusiastically blew out the candles and cut up slices of cake for everyone. The wives of the astronauts watched from the other side of the glass, and he pretended to hand them cake through the partition.

Armstrong died at age 82 after complications from cardiovascular surgery.