331K views · 538 shares | To warn predators they are toxic, railroad worms turn on the lights. | National Geographic | Facebook

16K views · 745 reactions | Once a year, this spectacle of "dancing" palolo worms gather together off the coast of Indonesia for a mass spawning. As they emerge from the reef, they release a special scent that triggers a mesmerizing egg-releasing wiggle 缾缾缾 #WelcomeToEarth | National Geographic TV | Facebook

#OTD in 1968, the crew of USS Pueblo crossed "The Bridge of No Return" after 11 months of captivity in North Korea. The Pueblo is still held by North Korea but remains an officially commissioned ship in the U.S. Navy. Among USN commissioned ships, only USS Constitution is older. | U.S. Naval Institute

#OTD in 1989, the USS Tennessee (SSBN 734) conducted the first undersea test launch of the Trident II ballistic missile off the coast of Florida. It did not go well. | U.S. Naval Institute