Subtitles section Play video Print subtitles Earth. November 14, 1969. Three astronauts, with spacesuits, food, water, and a battery of scientific and communications equipment, prepared to fly to the moon. Thousands gathered at the Kennedy Space Center in Florida, including President and Mrs. Richard Nixon, to witness the historic launch. It was raining that day, but that was no cause for delay. The ship that would carry them into space was designed to launch in any weather. But how would it respond to a powerful electrical storm now gathering above the launch pad? That was just the beginning of the incredible journey of Apollo 12. With three astronauts fastened into their seats, the countdown proceeded. Astronaut and Mission Commander Pete Conrad would say later: “The flight was extremely normal, for the first 36 seconds.” The five engines of the Saturn 5’s huge first stage were designed to burn through 5 million pounds of liquid oxygen in just two and a half minutes, and to send the spacecraft up 67 kilometers above the Atlantic Ocean. When it reached an altitude of 2000 meters, something unexpected happened. Racing through the stormy environment, the rocket generated a lightning bolt that traveled down its highly conductive exhaust trail. Another bolt hit 16 seconds later. All of the spacecraft’s circuit breakers shut off. The tracking system was lost. A young flight controller in Houston, Texas instructed astronaut Alan Bean on how to turn on an auxiliary power system. The mission was back on track. Once in Earth orbit, all systems appeared to check out, and flight control officials gave the crew the green light to leave Earth. The astronauts were not told of concern that the lighting strikes had damaged the pyrotechnic system used to deploy the parachutes that would ease them back through the Earth’s atmosphere. If that system failed, the astronauts would not return alive. This mission would have its share of perils, not unlike those faced by a long line of past explorers, whose courage and restless spirit propelled them into the unknown. This one, however, was backed by years of technology development, test flights, astronaut training, and the largest support team back home that any mission ever had. But hundreds of thousands of kilometers out in space the three astronauts were pretty much on their own. What made Apollo 12 unique was the friendship and chemistry of its crew. Conrad, Bean, and Richard Gordon were all Navy men. Working and training together on the Gemini program, they had gained each other’s respect and trust. Now, hurtling across more than 400,000 kilometers to the moon, they prepared to fullfill the mission’s goals. One was to set up a scientific station designed to record seismic, atmospheric, and solar data. Another was to visit an unmanned lunar probe called Surveyor III that had landed there two and a half years before. The idea was to bring back a part to study the effect of the lunar environment. A third goal was to improve on the landing of Apollo 11 just 5 months before. Dropping down over a region called the Sea of Tranquility, pilot Neil Armstrong found himself heading straight for a crater full of boulders. He had to fly over the planned landing site and find a new one. Now kilometers beyond the target, the lander, called Eagle, was literally running out of gas. With less than 30 seconds of fuel left, Neil Armstrong and Buzz Aldrin finally touched down on a landscape obscured by dust stirred up by the vehicle’s thrusters. Future astronauts would have to be able to make precision landings at locations dictated by science. That meant they would have to touch down on landscapes filled with all kinds of rocks and craters. For Apollo 12, the science pointed to a region known as the Ocean of Storms, some 2000 kilometers from where the Eagle had landed. Here, the landscape is dark from lava that cooled to form its flat expanse billions of years ago. Within it, an impacting asteroid had hollowed out Copernicus crater, perhaps showering the region with rocks blasted out from deep underground. To sample this geological treasure trove, the astronauts sought to land at a series of smaller craters about 45 kilometers away. After a journey lasting 83 and a half hours, the crew fired the spacecraft’s engine to go into an elliptical lunar orbit. Five hours later a second burn put the spacecraft into a circular orbit 111 kilometers above the lunar surface. The next day, Pete Conrad and Allan Bean entered the lunar module, Intrepid. Separating from the command module, they dropped down toward their target. Pete Conrad would rely on improvements in the ship’s landing radar to find his way to touchdown. Pete Conrad and Alan Bean landed without a hitch. Now, they prepared to climb down the ladder to experience a whole new world. The plan was for Earth to experience it too, courtesy of a color video camera that was designed to send back a live signal. Conrad was careful to keep it pointed away from the Sun to protect its sensitive imaging tubes. Unfortunately, it caught the glare from Intrepid’s shiny surface, and blew. Back on Earth, the television networks cancelled their coverage. Millions of viewers then went about their day. Which left Conrad and Bean to go about theirs’. The astronauts spent the first of two four-hour moonwalks setting up science and communications equipment, taking photographs, and seeing what was there. There were discoveries and surprises aplenty. One was a series of mounds out in the open, perhaps made up of material ejected from the craters upon impact. Two and a half hours into the moonwalk, the astronauts flipped their wrist-mounted checklists to their next task. They opened an unlikely page, placed there by the Apollo 12 back-up crew. This little prank hardly distracted from their central goal: to walk among the craters making observations and picking up rocks. That was part of a major, unheralded, scientific quest of the Apollo program: to find clues to where the moon came from. At the time, there were three leading theories. The so-called fission theory, championed by George Howard Darwin, son of Charles Darwin, held that the moon was once part of the Earth, cast off by the rapid spin of its young parent. That might explain the Pacific Ocean, a giant hole in the Earth’s surface. Then there was the capture theory, which held that the moon was a wayward object that floated through our solar system and was pulled into orbit by Earth’s gravity. A third idea came from the American astronomer Thomas Jefferson Jackson See, known at the time for his attacks on Einstein’s theories. He suggested that the Moon formed near Earth and gradually fell under its gravitational spell. In that case, moon rocks should resemble those of Earth. Finding out which theory is correct would also yield clues to the formation of the solar system at large, and perhaps even to the birth of our own planet. Day Two on the Moon. Neither Conrad nor Bean had been able to get much sleep. Excitement got the best of them. The pair now left Intrepid for a second, and final, moonwalk. The suits they wore had been built for spending time on the Moon’s surface, with five layers stitched together to maintain constant temperature and air pressure. Because direct exposure to the sun could heat the suits to 120 degrees Fahrenheit, the innermost layers circulated water around the astronaut’s body to keep him cool. On the outside was a shell to protect against micro-meteors that routinely batter the moon’s surface. The astronauts found that lunar dust was so abrasive that this outer layer quickly sustained damage, and so fine that it crept into the rotating wrist joints. This time, the plan was to move out along the edge of Surveyor Crater and pay the probe a visit. Along the way, there were pictures to take, samples to collect, coring tools to drive into the ground. It was a world filled with optical illusions and strange juxtapositions. The lunar landscape appears monochromatic, a bright gray. With no atmosphere, the light is harsh, with shadows cast in deep black. But close up, the moon offers a variety of rich and colorful details owing to its tumultuous past. The Ocean of Storms is an ancient basin that was hollowed out by a huge impact and filled with lava. Finally, the team arrived at Surveyor. They cut off select components to take back to Earth. Scientists would make a surprising discovery lodged in the camera was a colony of bacteria. Did it sneak into the component upon its return to Earth? Or, had it somehow survived for two and a half years on the moon? To this day, no one knows the answer to this intriguing question. One final stop remained: Block crater, where a basketball-sized impactor had exposed the lunar bedrock, leaving a wealth of new samples. One rock they picked up is known as KREEP, for potassium, rare earth elements, and phosphorus. It’s thought to be a piece of bedrock that formed over 4 billion years ago… on a lunar surface that was entirely molten. Just a few years later, this evidence would coalesce into a radical new idea of the moon’s origins. At the dawn of the solar system, Earth shared an orbit with a Mars-sized body now called Theia. Its orbit became unstable and it headed in Earth’s direction. Theia struck Earth at an oblique angle, causing the Earth to spin faster and debris from both bodies to fly into orbit. When the dust settled, the debris began to coalesce in Earth orbit, forming the Moon. The moon, then, comes primarily from the outer layers of the Earth and Theia. That’s why overall the moon is less dense than Earth. From this violent beginning, the moon gradually cooled, and the magma that lined its surface hardened into a crust. It was now time for Conrad and Bean to prepare for the return flight home. Along with their gear, they packed up 75 pounds of scientifically priceless dirt and rocks. In the years to come, these samples, and those from the remaining Apollo missions, would continue to yield clues to the history of the moon, and its companion, Earth. Even as Conrad and Bean lifted off from the moon, there was still more science to do. The lander rose up to join the command module, docking flawlessly. Conrad and Bean transferred their samples and equipment. Then they released Intrepid, sending it hurtling back down to the Lunar surface. The idea was to use the impact of a crash landing to calibrate equipment that would monitor moon quakes and asteroid impacts. When it hit, the impact resonnated like a bell for over half an hour, as seismic waves rippled through the moon’s interior. There was one more thing left to do: get home safely. Just before arrival, they gazed at a brilliant scene of Earth moving across the sun. Apollo 12 hit Earth’s atmosphere at 40,000 kilometers per hour. The parachute pack opened just fine.