Along with a team of explorers, Amazon founder and CEO Jeff Bezos plunged to the bottom of the Atlantic Ocean a few months ago to resurrect what he suspected were Apollo 11's lost F-1 engines.

Problem was, the ocean didn't care that it was home to priceless artifacts and wielded its corrosive power against the engines for more than 40 years. So when Bezos' team finally resurrected the F-1s, experts were unsure they would ever be able to positively identify the worn engines, as their serial numbers had succumbed to long-term exposure.

They were wrong. The ocean left behind some secrets — they just required some digging.

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After months of poring over the artifacts, one of the conservators spotted a fateful set of numbers while using a black light and special filter. Just four digits — 2044 — confirmed the team had indeed found one of the most important artifacts in space exploration history.

In a blog post Friday, on the eve of the 44th anniversary of Neil Armstrong's first step on the moon, Bezos explained the importance those numbers hold for his exploration team:

2044 is the Rocketdyne serial number that correlates to NASA number 6044, which is the serial number for F-1 Engine #5 from Apollo 11. The intrepid conservator kept digging for more evidence, and after removing more corrosion at the base of the same thrust chamber, he found it – "Unit No 2044" – stamped into the metal surface.

The F-1 engines supplied 1.5 million pounds of thrust to Apollo 11, helping power the astronauts to the moon. As planned, they submerged to the bottom of the ocean shortly after liftoff, where they remained for decades.

While Bezos' mission was 100% privately funded, he will turn over the engines to NASA, which will claim full ownership. Bezos will work closely with NASA to restore the engines for future public display.

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Image: Bezos Expeditions