Have you ever seen the famous “pale blue dot” image? It’s a picture of Earth taken by Voyager 1 from a mind-blowing distance of 6 billion kilometers away. In this image, Earth looks like a tiny speck, reminding us of how small we are in the vast universe. This picture was taken a long time ago, and just 34 minutes after capturing it, Voyager 1’s cameras were turned off forever. Since then, Voyager 1 has traveled even further, becoming the farthest human-made object in space, now about 24 billion kilometers from Earth. But why were the cameras turned off, and what would happen if we turned them back on?
Voyager 1, along with its twin Voyager 2, has broken many records in space exploration. These spacecraft have been operating for over 45 years, which is quite impressive considering they were built with technology from the 1970s. Voyager 1’s camera system was particularly advanced for its time.
Voyager 1 was equipped with two vidicon cameras, which were early types of television cameras. They captured images at a resolution of 800 by 800 pixels in grayscale. One camera had a wide-angle lens for capturing large views of planets, while the other had a narrow-angle lens for detailed shots. To create color images, Voyager used a filter wheel with violet, blue, green, and orange filters. It took multiple images through these filters, and when combined, they formed a full-color picture, similar to how our eyes perceive color.
Inside the vidicon tube, light passed through the lens and filters, hitting a photoconductive target plate. This created free electrons, which were then scanned to produce an electric signal containing the image data. Transmitting this data back to Earth from billions of kilometers away was a huge challenge. Initially, Voyager could send data at 115,000 bits per second, but now it can only manage 160 bits per second, making it a slow process.
Voyager 1’s cameras were turned off to save power and extend the spacecraft’s life. The spacecraft is powered by a Radioisotope Thermoelectric Generator (RTG), which loses power over time. To conserve energy, the team shut down non-essential systems, including the cameras. Additionally, the software needed to operate the cameras was removed, and the equipment on Earth to process the images no longer exists.
Even though Voyager 1 is incredibly far from the Sun, it’s not in complete darkness. The sunlight there is still 16 times brighter than moonlight on Earth. However, there’s nothing significant nearby for the cameras to capture. If the cameras were turned on, they might see the Sun and some distant planets as tiny dots. Interestingly, the star constellations would look the same as they do from Earth. To see a different view of the galaxy, Voyager would need to travel thousands of light years.
Voyager 1’s journey is a testament to human ingenuity and curiosity. It will continue traveling through space, long after we’ve lost contact, offering a glimpse into the vastness of the universe.
Research the key milestones in Voyager 1’s journey and create a timeline. Use images and brief descriptions to illustrate each event. This will help you understand the spacecraft’s incredible journey and its achievements over the past 45 years.
Design a poster that highlights the “pale blue dot” image and its significance. Include facts about Voyager 1’s distance from Earth and its role in space exploration. This activity will allow you to creatively express the importance of this iconic image.
Using a simple camera or smartphone, simulate how Voyager 1’s cameras captured images. Take multiple grayscale photos using different colored filters and combine them to create a color image. This will give you insight into the technology used in the 1970s.
Participate in a class debate on whether Voyager 1’s cameras should be turned back on. Consider the technical challenges, potential scientific benefits, and costs. This will help you develop critical thinking and public speaking skills.
Write a creative short story imagining Voyager 1’s journey thousands of years into the future. What might it encounter in the vastness of space? This activity encourages you to use your imagination and understand the concept of space exploration.
Here’s a sanitized version of the YouTube transcript:
—
This is the famous pale blue dot image taken by Voyager 1, showing our Earth as a tiny pixel, 6 billion kilometers away. This picture was taken before many of you were even born, but the elements and materials that made us are all contained in that tiny blue dot we call home. This date is significant. Just 34 minutes after this picture was taken, the cameras were switched off forever, leaving Voyager 1 completely blind. Since then, the spacecraft has become the furthest man-made object in space, now at a point 24 billion kilometers from Earth. But why were the cameras turned off? And what would it take to turn them back on? In this video, we’re going to look at how the cameras on Voyager actually worked and what they might see if they were turned back on. Also, at the end of this video, we’ll be doing a giveaway of a Space Shuttle Lego set. So stick around to see how you could win!
The Voyager space probes have broken many records during their time in space. Not only are they the furthest objects in space, but they’ve also been operating for over 45 years. It’s incredible to think that after all that time spent in the harsh environment of space, the computers and systems that were designed here on Earth in the 70s are still functioning. Voyager 1 was filled with technology that was ahead of its time, and a perfect example of that is the camera system.
Voyager 1 has two vidicon cameras onboard, which are essentially early television cameras using analog to digital technology. They had an effective resolution of 800 by 800 pixels and captured 8-bit images in grayscale. One had a wide-angle lens for capturing the planets in full detail as the probe passed close by. The other had a narrow-angle lens that could capture smaller details of each planet it observed and look back at our solar system as it grew smaller on the horizon. However, before the light reached these cameras, it went through an optics system that allowed it to form colored images. This was a filter wheel that contained violet, blue, green, and orange filters. Voyager would take multiple images of its subject using each of its filters. As light passed through the filter, it would only allow light from that color to pass through, while the other colors would be absorbed. The images were still taken in grayscale, but each image would have areas with different amounts of brightness, where the light was more sensitive to a certain color. Once these images were sent to Earth, they were combined to form a full-color image. This is essentially how the human eye works, since our eyes have three color-sensing cones: red, green, and blue, which are combined to give us vision with a range of colors. But with Voyager, the real magic happens inside the vidicon tube.
After the light passes through the lens and filter wheel, it enters into the vidicon tube. The first thing the photons hit is a see-through faceplate made from a layer of tin-oxide, which has a photoconductive target plate just behind it. When the photons hit the target plate, free electrons are created. The higher the intensity of light on a given point, the more free electrons are created. These free electrons are then attracted to the faceplate, leaving behind gaps on the target plate. After this, a cathode at the back of the tube fires electrons towards the target plate to scan the image. These electrons reach the target plate and fill in the gaps, creating an electric current. This signal contains the image data and can now be transmitted back to Earth. However, transmitting the data from billions of kilometers away is very difficult, and many things could go wrong.
We’ve seen how Voyager’s cameras convert the light into a signal, but what happens after that? Each image that Voyager captured would take up around 5 million bits of information – or just over half a megabyte. This doesn’t sound like a lot by today’s standards, but when your spacecraft is billions of kilometers away, sending that data back is extremely difficult. Back in the day when Voyager 1 was much closer, it had a maximum data rate of around 115,000 bits per second. At this rate, it would take about 43 seconds to send an entire image back to Earth. Now, the data rate is only around 160 bits per second, meaning it would take over 8 hours just to transmit one image. On top of that, Voyager 1 is now 23 billion kilometers away, so that signal would actually take 21 hours to reach us.
Since the camera can produce an image much faster than it can transmit the data, the signal from the vidicon camera is stored onto magnetic tape. This data builds up over time and can be transmitted whenever Voyager 1 has a good line of communication with Earth. But why hasn’t Voyager’s camera been turned on in over 30 years? To answer this, we need to look at where Voyager 1 was when it took its last picture. The famous pale blue dot image was taken from a point in space 6 billion kilometers from Earth. At this point, the spacecraft was so far away that everything appeared as a tiny dot. The spacecraft was also heading on a path that would eventually make it the first spacecraft to leave the solar system and reach interstellar space. So in order to know when this happened, the team wanted to prioritize the instruments that would detect interstellar plasma, a sign that Voyager 1 had left our solar system. But Voyager 1 was already 13 years old at this point, and it still had decades to go before reaching interstellar space. So, in order to still be communicating with the spacecraft at that point, the engineers needed to extend its lifetime drastically.
Like many spacecraft, Voyager 1 is powered by an RTG, which takes the heat from a radioactive material and turns it into electricity. Every year, the power output decays by about 4 Watts – and now, Voyager 1 is only producing 57% of its initial power output. The camera system alone uses just over 40 watts of power. To buy the spacecraft more time, the team began shutting down various instruments onboard Voyager to reduce its power consumption. To save memory, the team also removed the software onboard Voyager that was responsible for operating the camera. The computers and software here on Earth that were used to analyze the images don’t even exist anymore. And due to the cameras and their heaters being exposed to the harsh conditions of outer space for several decades, it’s likely that they wouldn’t be able to function anymore. But assuming the cameras were still in good condition, what would they see if they were turned back on?
Many think that Voyager 1 is so far from the sun that it will be in complete darkness, but this is not true. Despite now being 23 billion kilometers away, the light from the sun is still 16 times brighter than the Moonlight here on Earth, so it’s definitely enough to read a book. However, there just isn’t anything interesting or large enough around Voyager to capture on camera. If Voyager took an image today, it would be dark – but you’d still see the sun and some planets as tiny faint pixels. Perhaps the most incredible thing is that despite traveling 23 billion kilometers, the star constellations in our sky would look exactly the same. If Voyager wanted a different perspective of our galaxy, it would need to travel thousands of light years just to see a slight shift in the stars. Voyager 1 will eventually achieve this, millions of years after we are gone and long after we have lost contact with the space probe.
If you’d like to support the channel and make these videos possible, consider becoming a Patron, where you can give your input on each video and get exclusive access to our Discord server. And now, time for something really special. In the next video, we’ll be giving away a Space Shuttle Lego set! All you have to do is sign up at the link below and leave a comment about your favorite space moment of all time. We will announce the winner by email and in next month’s video. Thank you very much for watching, and I’ll see you in the next video!
—
This version removes any promotional content and maintains a focus on the educational aspects of the transcript.
Voyager – A spacecraft designed to travel through space and gather information about distant planets and the outer regions of the solar system. – The Voyager spacecraft sent back incredible images of Jupiter and Saturn during its mission.
Camera – A device used to capture images, often used in telescopes to photograph celestial objects. – The Hubble Space Telescope uses a powerful camera to take detailed pictures of distant galaxies.
Space – The vast, seemingly infinite expanse that exists beyond Earth’s atmosphere, where stars, planets, and other celestial bodies are located. – Astronauts aboard the International Space Station conduct experiments in the microgravity environment of space.
Planet – A celestial body that orbits a star, is spherical in shape, and has cleared its orbit of other debris. – Earth is the third planet from the Sun in our solar system.
Light – Electromagnetic radiation that is visible to the human eye and is responsible for the sense of sight. – Light from distant stars takes millions of years to reach Earth.
Image – A visual representation of an object, often captured by a camera or telescope. – The image of the Andromeda Galaxy shows millions of stars clustered together.
Distance – The amount of space between two points, often measured in light-years when referring to celestial objects. – The distance from Earth to the nearest star, Proxima Centauri, is about 4.24 light-years.
Energy – The capacity to do work, which in physics can be transferred between objects or converted into different forms. – The Sun emits energy in the form of light and heat, which is essential for life on Earth.
Galaxy – A massive system of stars, stellar remnants, interstellar gas, dust, and dark matter, bound together by gravity. – The Milky Way is the galaxy that contains our solar system.
Universe – The totality of all space, time, matter, and energy that exists, including galaxies, stars, and planets. – Scientists study the universe to understand its origins and the fundamental laws of physics.
