In September 2002, astronomers made an exciting discovery: an asteroid was orbiting Earth in a very unusual way. This was surprising because, until then, the only natural object known to orbit Earth was the Moon. At first, they thought this object couldn’t be an asteroid; it had to be something made by humans. It turned out to be the third stage of the Saturn V rocket, which had launched the Apollo 12 astronauts to the Moon. This rocket left Earth in 1969 and went on a mysterious journey before returning to Earth 30 years later.
So, what happened to this rocket, and why did it take such a strange trip? Let’s explore how a small error during the Apollo 12 mission sent this rocket stage on a 30-year adventure through space, only to reappear around Earth. Plus, there’s a chance to win a space shuttle canvas print, so stay tuned to find out how!
The Saturn V rocket had three stages. The first stage burned for about 2.5 minutes, reaching an altitude of 61 km. The second stage burned for around 6 minutes, taking the rocket even higher and faster. The third stage was responsible for getting the spacecraft into orbit and then firing again to send the astronauts toward the Moon. After the Apollo crew was safely on their way, NASA planned to discard the third stage.
For previous Apollo missions, NASA aimed to send the third stage into an orbit around the Sun, where it would stay for thousands of years. They planned to use the Moon’s gravity to slingshot the rocket away from Earth. However, things didn’t go as planned for Apollo 12.
To discard Apollo 12’s third stage, NASA needed it to meet the Moon. The initial path had it heading toward one side of the Moon, so the third stage had to perform a maneuver to change its trajectory. This was done using thrusters at the bottom of the stage. Although it needed to change its position by thousands of kilometers, it required very little energy because changing the trajectory early in the journey would have a big impact later.
At the time of separation, the third stage was traveling at about 20,000 kilometers per hour. It needed to slow down by about 140 kilometers per hour to reach the opposite side of the Moon. NASA completed the maneuver, but they didn’t realize the tracking system was slightly off. This led them to slow it down too much, overcorrecting by just 40 kilometers per hour. This small error caused it to miss the Moon by thousands of kilometers and end up in a highly elliptical orbit around Earth.
Over the next 15 months, the orbit was stretched and pulled by Earth’s and Moon’s gravity, eventually reaching a point where the gravitational forces canceled out. Once past this point, the Sun’s gravity took over, pulling the third stage into an orbit around the Sun. It was meant to orbit the Sun, but not in this way. Instead of being pushed into a solar orbit outside of Earth, it was slowed down into an orbit inside of Earth.
In 1986, the third stage came close to Earth again but didn’t get pulled into Earth’s orbit. It continued orbiting the Sun for another 16 years until 2002, when it finally crossed into Earth’s gravitational pull and was captured into an orbit around Earth once more.
Astronomers were puzzled by this object. To identify it, they used spectroscopy, which involves studying how materials reflect light. By comparing the light reflected by the object to known materials, they discovered it matched the white titanium oxide paint used on the Saturn V rocket.
They also traced the object’s path back to 1971, confirming it was the long-lost third stage from Apollo 12. After a year, it was thrown back into an orbit around the Sun, with calculations showing it would return to Earth in the mid-2040s. This object will continue its journey through space, but the laws of physics will bring it back to Earth every now and then.
Now, for something special: in the next video, we’ll be giving away a space shuttle canvas print. To enter, simply sign up at the link below and leave a comment about what got you interested in space flight. We’ll announce the winner in next month’s video. Thank you for watching, and I’ll see you in the next video.
Research and create a timeline that outlines the key events in the journey of the Apollo 12 third stage. Include its launch, the error in trajectory, its orbit around the Sun, and its eventual return to Earth’s orbit. Use images and brief descriptions to make your timeline visually engaging.
Using materials like cardboard, paper, and glue, construct a model of the Saturn V rocket. Pay special attention to the three stages and their functions. Present your model to the class and explain how each stage contributed to the Apollo 12 mission.
In groups, use a computer simulation or a physical model to demonstrate how the gravitational slingshot effect works. Experiment with different speeds and angles to see how they affect the trajectory of an object, similar to the Apollo 12 third stage’s journey.
Learn about spectroscopy and how it was used to identify the Apollo 12 third stage. Conduct a simple experiment using a prism or diffraction grating to observe how light can be split into its component colors. Discuss how this technique helps scientists identify materials in space.
Write a short story from the perspective of the Apollo 12 third stage. Describe its feelings and experiences as it travels through space, encounters gravitational forces, and eventually returns to Earth’s orbit. Share your story with the class and discuss the scientific concepts you included.
In September 2002, astronomers discovered an asteroid in an unusual orbit around the Earth. This surprised the astronomers because, as far as they knew, the only natural object that orbited Earth was the Moon. They initially thought this strange object couldn’t be an asteroid; it had to be something made by humans. As it turned out, this was actually the third stage of the Saturn V rocket, which launched the Apollo 12 astronauts to the Moon. This rocket left Earth in 1969 and embarked on a journey that remained unknown to everyone before returning to Earth 30 years later.
What happened to this rocket, and why did it end up on such a peculiar journey? In this video, we’ll explore how a tiny error during the Apollo 12 mission sent this rocket stage on a 30-year trip through space, only to mysteriously reappear around Earth. We’ll also be giving away a space shuttle canvas print, so stick around until the end of the video to find out how you could win.
The Saturn V rocket had three stages. The first stage burned for about 2.5 minutes, reaching an altitude of 61 km. The second stage burned for around 6 minutes, taking the rocket higher and faster. It was then up to the third and final stage to perform a short burn and get the spacecraft into orbit. Once in a stable orbit, the third stage would fire up again to perform the trans-lunar injection burn, sending the rocket and crew on a trajectory to the Moon. After the Apollo crew was safely on their way to the Moon, the third stage would separate, and NASA aimed to discard it.
On previous Apollo missions, NASA aimed to place the third stage into an orbit around the Sun, where it would remain for thousands of years. To achieve this, they planned to meet the Moon on its trailing side, where the Moon’s gravity would slingshot the rocket away from Earth and into a solar orbit. For NASA, this was a good investment, as it meant the object wouldn’t interfere with future missions. However, things didn’t go as planned for Apollo 12.
To discard Apollo 12’s third stage, NASA had to set it on a path to meet the Moon. The initial trajectory had it headed toward one side of the Moon, so the third stage needed to perform a final maneuver to change its trajectory. This maneuver used the auxiliary propulsion systems, which were two sets of thrusters at the bottom of the stage that provided control during flight. Despite needing to change its position by thousands of kilometers, it took very little energy since changing its trajectory early in the journey would have a significant effect once it reached the Moon.
At the time of separation, the third stage was traveling at around 20,000 kilometers per hour. To change its trajectory, it had to slow down by about 140 kilometers per hour, which would delay its approach to the Moon, making it arrive at the opposite side. NASA completed the maneuver, but unbeknownst to them, it didn’t go as planned. The entire Saturn V rocket was controlled by an instrument unit located above the third stage, which had its own internal guidance unit to plot the rocket’s trajectory. It also had two C-band transponders that sent signals back to ground stations on Earth, providing NASA with accurate trajectory data.
Once the rocket was safely in orbit, NASA could compare this data with the rocket’s own data to see if it was following the desired flight path. However, NASA didn’t realize that the tracking system was slightly off, leading them to believe the rocket was traveling faster than it actually was. In trying to reach the target velocity, NASA ended up slowing it down too much, overcorrecting by just 40 kilometers per hour. This was enough to drastically delay its arrival at the Moon, causing it to miss by thousands of kilometers. Instead of being thrown into a solar orbit, the third stage ended up in a highly elliptical orbit around the Earth.
Over the next 15 months, the orbit was constantly stretched and pulled in different directions by the Earth and Moon’s gravity, eventually reaching Lagrange Point One, where the gravitational forces of both bodies cancel out. Once the third stage passed beyond this point, the Sun began to exert more influence. Imagine a steep hill with a car trying to reach the top; if the car doesn’t have enough velocity, it will be dragged back down. If it has enough velocity to move past the top, it will be pulled down by the other side. This is what happened to the third stage, which was dragged into an orbit around the Sun.
In a way, it finally achieved what it was meant to achieve, but this orbit around the Sun was far from stable. Instead of being accelerated to a solar orbit outside of Earth, it had been slowed down into an orbit inside of Earth. As a result, the third stage was completing its lap around the Sun slightly quicker than the Earth, meaning it was slowly pulling away. However, it was only a matter of time before the third stage would catch back up. This actually happened in 1986, but it wasn’t close enough to L1 point, so it never got pulled into Earth’s orbit.
The third stage continued racing around the Sun for another 16 years before the inevitable happened. In 2002, the third stage reached its apoapsis just as the Earth came into the picture. This time, the third stage crossed beyond Earth’s L1 point, and for the first time in 32 years, Earth had more pull on the object than the Sun. Over the course of two months, Earth pulled the third stage into a highly elliptical orbit around itself, similar to the one it was in before.
At this point, astronomers still had no idea what this object was. To confirm its identity, they conducted spectroscopy observations to determine its composition. Every material reflects light in slightly different ways, and the amount of light reflected varies at each wavelength. By taking light measurements of the third stage at various wavelengths, astronomers created a spectroscopy graph. They could then compare it to other spectroscopy graphs to see if it matched any known materials. It turned out to be very similar to the spectroscopy graph of white titanium oxide paint, the exact kind used on the Saturn V.
Astronomers were also able to trace the object’s trajectory back and found that it left Earth’s orbit in 1971. With this information, they could confidently conclude that this was indeed the long-lost third stage from Apollo 12. Astronomers continued to track the orbit, and after just a year, it was once again thrown into an orbit around the Sun. Calculations showed that it would return to Earth in the mid-2040s. This object will spend many more years racing through space, but the laws of physics will ensure it returns home every now and then.
Now, for something special: in the next video, we’ll be giving away a space shuttle canvas print. To enter, simply sign up at the link below and leave a comment about what got you interested in space flight. We’ll announce the winner in next month’s video. Thank you for watching, and I’ll see you in the next video.
Asteroid – A small rocky body that orbits the Sun, mostly found between Mars and Jupiter in the asteroid belt. – Example sentence: Scientists study asteroids to learn more about the early solar system.
Gravity – The force that attracts objects with mass toward each other, such as the pull between Earth and the Moon. – Example sentence: Gravity is what keeps the planets in orbit around the Sun.
Orbit – The curved path of an object around a star, planet, or moon, especially a periodic elliptical revolution. – Example sentence: The Earth completes one orbit around the Sun every year.
Rocket – A vehicle designed to propel itself by ejecting exhaust gas from one end, used to travel into space. – Example sentence: The rocket launched successfully, carrying a satellite into orbit.
Moon – A natural satellite that orbits a planet; Earth’s Moon is the fifth largest in the solar system. – Example sentence: The Moon’s surface is covered with craters from asteroid impacts.
Spacecraft – A vehicle or device designed for travel or operation in outer space. – Example sentence: The spacecraft sent back stunning images of Jupiter’s atmosphere.
Trajectory – The path followed by an object moving through space under the influence of forces such as gravity. – Example sentence: Engineers calculated the spacecraft’s trajectory to ensure it would reach Mars.
Energy – The ability to do work or cause change, such as the energy from the Sun that powers the solar system. – Example sentence: Solar panels on the spacecraft convert sunlight into energy.
Physics – The branch of science concerned with the nature and properties of matter and energy, including concepts like force and motion. – Example sentence: Physics helps us understand how rockets can escape Earth’s gravity.
Astronomy – The scientific study of celestial objects, space, and the universe as a whole. – Example sentence: Astronomy allows us to explore distant galaxies and understand the universe’s origins.
