To respond to the Do Now, you can comment below or tweet your response. Be sure to begin your tweet with @KQEDEdspace and end it with #DoNowJunk

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Do Now

Weigh the value of launching satellites, rovers, spacecraft and other items into space for our benefit against the risks and dangers of increasing the amount of space debris. Which is more important? Should we be worried about limiting space junk?


Recently China successfully launched their first moon rover, Chang’e-3, into orbit. Unfortunately later that day pieces from the launch rocket fell off and destroyed the homes of two citizens. Although nobody was harmed, the falling spacecraft still worried many people. This incident has led Chinese citizens to demand their government provide insurance plans guaranteeing compensation for the loss of property or any deaths or injuries that may occur from other launches in the near future. In fact, due to the launch of the Long March, Chinese authorities evacuated up to 180,000 people from the provinces near other launch sites in order to ensure the safety of civilians.

Space junk or debris is categorized as any man-made object orbiting in space that no longer serves a useful purpose. This includes old satellites, rocket stages used to send the satellites into orbit, bolts and objects released during satellite deployment, and fragments from the accidental breakup of large objects. Space junk can linger in orbit for many decades at very high altitudes and continues to build up as more is produced. As more and more space junk accumulates around Earth, the likelihood that it will collide with functioning satellites increases dramatically. These collisions can take place at the speed of thousands of miles per hour, so even a collision of a tiny fragment can be disastrous and destroy a spacecraft worth billions of dollars. Every time a collision occurs, thousands of new pieces of debris can be formed. Nowadays, space junk is being produced at a faster rate than it can burn up in the atmosphere.

So why should we be concerned? The existence of space junk affects our daily lives more than we know it. Nearly a hundred tons of space junk falls from orbit every year. Most of it falls into the vast ocean or just burns off in the atmosphere. However, some of this space junk falls in populated areas and causes damage, as happened with China’s recent launch. Satellites serve many purposes and are vital to communications, military strategy and environmental monitoring. If these satellites, that cost hundreds of billions of dollars, were to get struck by a tiny piece of space debris moving at the speed seven times faster than a rifle bullet, our communications could be interrupted or evenly permanently terminated. And with the buildup of space debris, the risk of satellites being destroyed by colliding debris only increases.


PBS NewsHour video Will Space Junk Collide With Plans for Future Exploration?
Hear from Donald Kessler, former head of NASA’s orbital debris research program, about space debris. He discusses how much is out there, what it looks like, what happens when pieces of debris collide and the danger it poses for future space travel and for us.

To respond to the Do Now, you can comment below or tweet your response. Be sure to begin your tweet with @KQEDedspace and end it with #DoNowJunk

For more info on how to use Twitter, click here.

We encourage students to reply to other people’s tweets to foster more of a conversation. Also, if students tweet their personal opinions, ask them to support their ideas with links to interesting/credible articles online (adding a nice research component) or retweet other people’s ideas that they agree/disagree/find amusing. We also value student-produced media linked to their tweets like memes or more extensive blog posts to represent their ideas. Of course, do as you can… and any contribution is most welcomed.

More Resources infographic Space Junk Explained: How Orbital Debris Threatens Future of Spaceflight
Learn about the amount and kind of space debris orbiting the Earth, what its impact is and ideas for cleaning it up.

Scientific American interactive A Minefield in Earth Orbit: How Space Debris Is Spinning Out of Control
This interactive includes an introduction to the space debris problem, six reasons to worry, graphics on how the debris spreads in orbit and charts depicting who is responsible the junk in space.

NPR article U.S. ‘Space Fence’ Radar System Goes Silent, After 50 Years
Read about the “Space Fence,” a U.S. radar system that tracks thousands of objects orbiting Earth, that was shut down in September.

NASA website Orbital Debris Program Office
The NASA Orbital Debris Program Office studies leads NASA’s space debris research, focusing on the following: modeling, measurements, protection, mitigation and reentry.

KQED Do Now Science is a monthly activity in collaboration with California Academy of Sciences. The Science Do Now is posted every second Tuesday of the month.

This post was contributed by youth from the Spotlight team within The California Academy of Sciences’ Careers in Science Intern Program. CiS is a multi-year, year-round work-based youth development program for young people from groups typically under-represented in the sciences.

How Worried Should We Be About Space Junk? 8 March,2017California Academy of Sciences

  • Aidan Nelson

    #ratzel85. Space debris is a true danger to people but it is caused when we get our important satellites and rockets into space. As shown by the image of the space debris currently orbiting the planet, there is a vast amount of space debris that poses a threat to people. Though getting our satellites and rockets into space is important, the amount of space debris already in orbit increases every time we launch something into space. Also a quote from the text states “These collisions can take place at the speed of thousands of miles per hour, so even a collision of a tiny fragment can be disastrous and destroy a spacecraft worth billions of dollars. Every time a collision occurs, thousands of new pieces of debris can be formed. Nowadays, space junk is being produced at a faster rate than it can burn up in the atmosphere”. This further shows the dangers of space debris showing that there is more space debris being produced faster than it can burn up in the atmosphere which would explain the Chang’e-3’s debris destroying those two homes. In conclusion, I believe that space debris is a danger to people and though satellites and rockets are important, the disadvantaged far outweigh the advantages and we must find another alternative that doesn’t produce more space debris.
    I would very much like to hear your opinion on the subject and feel free to reply

    • ratzelster

      Dear Aidan,
      You’ve written clearly about this topic and I can tell what you think. So you think the danger of space junk outweighs the benefits that the “things” are providing us. Are there things you think we must allow even if it’s dangerous?

  • Connor Clary

    The amount of time and money spent to prevent space junk should not be overpowering the amount that the issue itself calls for. We should be limiting space junk, but not spending too much time and money on it, as it is not a large threat to humans on earth. However, we should still be attempting to limit the amount of space junk that is formed, and limiting the amount that is colliding in space and forming more individual pieces of space junk. “Every time a collision occurs, thousands of new pieces of debris can be formed. Nowadays, space junk is being produced at a faster rate than it can burn up in the atmosphere” (California Academy of Sciences). Over time, this could cause space junk to become a much larger issue than it currently is, so we need to begin limiting the amount that we create, and ridding of what currently exists. If we wait too long, it could cause very large issues.

    • ratzelster

      Thx Connor 4 your ideas. When you say that $$$ should not be overpowering. What do you mean? I really like the way you used a source in your post.

    • Jae Hun

      I agree with Connor. Yes, we should be putting effort in to eliminate space junks, but not spending bunch of money on it. We should be spending money on things we actually need. If pieces of debris forms in to big piles, no one will know what will happen to it.

  • Aimee Howes

    How worried should we be about space junk? Is this on the same level as asteroids?

    Space junk is classified as debris that is man-made, and no longer useful . Once it has lost its purpose, it orbits through space, colliding with satellites and causing issues. the big question is, what do we have to worry about with all this space junk floating around our home planet? Right now, space junk is piling up in big clusters. The more that collects, the more risk we have of more destroyed satellites, and thus, more of a risk of this debris harming citizens of our earth. On top of all of this, we are wasting money on these highly expensive projects for them to be torn apart, all too easily. Now that we know the main dangers of this debris orbiting our earth, we can look at what these effects may have on people and the harm that they can do.

    “Nearly a hundred tons of space junk falls from orbit each year” (KQED article). Even though hundreds of tons of debris is falling every year, there is still far too much out there for the atmosphere to burn up. This junk can fall out of orbit and collide with people’s homes and properties at hundreds upon hundreds of miles per hour. Areas around launch sites have been evacuated for the safety of the people living there, but the risk is nearly as great at any other place. This space junk is threatening peoples’ lives every day, and if discovering new life is going to put so many in risk, then we shouldn’t be trying to find it at all.

    At this point, this debris is just as great as the risk of asteroids, if not greater. After all, we can track asteroids long before they threaten the earth, so we can stop them, especially if they are one large mass object. However, this space debris is hundreds of metal scraps, the remains of satellites, and pretty much unable to be stopped. At this point, everyone who has a right to live on this planet is at risk, and if the amount of debris continues to grow at such a steady and startlingly fast rate, then there will be more debris than people on our home planet. Everyday, people’s lives are threatened by this junk floating around our planet. If we can’t stop it, then we will at least need to know how to track it and, eventually, save peoples’ lives from this deadly space junk.

  • Jasmine Masih

    We should be concerned about space junk because we are polluting our universe. It is also effecting people around us. People have lost their homes because of space junk and there should be a better disposal for this. People should not be worried about something falling out of the sky and wrecking their homes. “More than 21,000 orbital debris larger than 10 cm are known to exist. The estimated population of particles between 1 and 10 cm in diameter is approximately 500,000. The number of particles smaller than 1 cm exceeds 100 million.” (NASA Orbital Debris Office)

  • Francesca Botto

    I think that space is junk is something that needs to be recognized and to be concerned for because it does pollute our world and it effects people around us. When it comes to the point that people’s lives and homes are in danger because of debris falling from the sky. then something needs to be done. I think that we need come up with a better way of disposing this junk. Space junk also effects the satellites and rovers that roam through space. These units are very expensive and more money is used when they break. The government could save money needed for replacing the satellites by creating new disposal methods.

    • Emma V.

      @francescabotto:disqus I agree something needs to be done. If you click on the first link and scroll down, there are some proposed solutions to the problem. You might want to give those a look

  • Caroline P

    The fear of the presence of space satellites should not stop us from sending them into our universe. We must discover and learn new things about our universe, and the only way to do so is by sending spacecrafts and rovers out to collect information. Although the universe is incredibly vast, we must start somewhere with collecting data, even if there is a possibility of space satellites turning into space junk. Space junk is terrifying, and incredibly worrisome. Our nation must do something about the space objects they send out so that injuries, and even deaths do not occur. Although collecting data is necessary, the space junk that is left alone is not. Space junk should be cleaned up due to its potential to harm large amount of people. The longer we ignore the issue, the worse it will get.

    • Emma V.

      @ Caroline P. Which side are you taking? Your points are valid, but it seemed that you are arguing to both not worry about space junk and keep exploring space but then going on to say that we SHOULD worry about it.

  • Alex M

    Space Junk is a rapidly growing problem that we need to find a solution to soon. It will have a lasting impact on our communications and many peoples lives if it continues to destroy satellites and homes. It is majorly polluting our oceans and could take lives. We need to clean as much up as possible.

    • Emma V.

      @Alex M. I agree. Space junk is a big problem and it will affect our lives if we don’t fix it.

  • Emma V.

    @KQEDedspace There are a lot of things to be done to minimize the damage and clean up space junk, and those measures need to be taken so this problem will not be sent down to future generations to fix. #DONOWjunk

  • Emma V.

    @KQEDedspace There is so much space junk in LEO (low earth orbit) that astronauts and future space travelers and expensive equipment would be jeopardized. “Even a collision of a tiny fragment can be disastrous and destroy a spacecraft worth billions of dollars” (How worried should we be about space junk? ). The odds of collision increase every time a new collision occurs. This is called the Kessler system, and it is a concerning problem for all of the satellites and other thing in LEO. #DONOWjunk

  • Aabid Jamshed

    @KQEDedspace Space Junk does not really pose a massive threat to human life on Earth’s surface. It is more dangerous to the satellites and such in orbit. It also threatens the oceans that they fall in, as foreign materials such as plastic and metal and the sort can majorly pollute the water around them, killing fish and other marine life. This, in turn, exhausts food supplies for people and animals alike, driving species extinct and throwing the ecosystem off balance. In short, space junk must be dealt with.
    -Ms. Chen’s Student

  • Safaa Jamshed


    I think that we should be worried about space debris. According to studies, about every three days some kind of space junk lands on earth. Although much of this is not harmless, occasionally something harmful will crash into the earth, like the incident in china, which could have hurt many people. There are many theories and ideas that could be tested to finally get rid of space junk. I think that they should be tested one by one. Eventually, something will work and we can use this method to slowly decrease and eventually eliminate debris in outer space.

    Miss Chen’s Student sending a Tweet as well!

  • Derek

    @KQEDedspace #DONOWjunk
    Space junk is a threat to us, especially in the next 50+ years. Objects will collide with meteorites and cause them to possibly hit other meteorites or objects. This could cause debris to possibly fly towards earth. Thus, posing a threat to us which we should be worried about.

  • Rhyann G.

    We should be worried about limiting space junk for multiple reasons due to destruction they can cause. The U.S sends many rovers and satellites and many other objects we use for testing into space but we cant get alot of work done if all of our resources are destroyed due to destruction space junk causes. Not only can space junk can cause alot of damages to expensive objects in space but its also dangerous to all humans and animals around the Earth. “Nearly a hundred tons of space junk falls from orbit every year. Most of it falls into the vast ocean or just burns off in the atmosphere” (KQED). You never always predict what will happen to objects that are in space, it can turn into something good or bad but it will have an effect on multiple humans and living creatures and animals.

  • Alex G

    I think that we should limit the junk in space. We are wasting money by sending satellites up in space to be crushed by debris going up to a thousand miles per hour. We have bigger problems than using money for Space Programs. I think that if we gather five space rocks a year for the next one hundred years we could start NASA back up. It is just to dangerous for astronauts and citizens on earth. I also think its a threat to ocean life as well, as some other people stated. Marine life could be threatened because there could be many poisonous gasses and chemicals in space and now in the ocean. I do think that space junk is a problem it’s just that what do you do with it all? @KQEDedspace #DONOWjunk

  • Abbey Sensenich

    @KQEDEdspace Launching satellites, rovers, spacecraft, and other items into space for human benefits is deleterious because doing so could increase the amount of space debris in the atmosphere. There have been heated debates on this subject, and questions about which is more important; getting rid of space clutter or propelling man made components into the atmosphere. Both sides have copacetic arguments with valid points. For instance, one viewpoint from the public is that, “The rising population of space debris increases the potential danger to all space vehicles, but especially to the International Space Station, space shuttles and other spacecraft with humans aboard,” (“Space Debris and Human Spacecraft.” Ed. Mark Garcia. N.p., 27 Sept. 2013). In other words, this article elaborates on the dangers of space debris to not only human technology, but even the humans themselves! This proves that satellites and other such items should either not be launched into space, or a way to be rid of space junk should be established. Although, the other standpoint foresees launching spacecraft as being necessary, especially to future discoveries, and also to just quench the thirst of curious followers of events in space and such activities. Limiting the amount of space junk in the atmosphere should most likely be prioritized to space officials. Although, this does not mean space launches have to be halted, they can continue, just at a moderated pace and in smaller masses. In conclusion, space debris is a growing problem in the atmosphere, although it can be helped through constraining the amount of spacecraft launched into space. In the meantime, experts in the necessary fields of science could band together and find a solution of how to get rid of all of the space clutter. #DoNowJunk

  • Croix Ratzlaff

    #ratzel85. Space junk is a danger to us and most space junk within 600 miles will fall to Earth within 100 years, although it doesn’t oppose much of a threat to humans it can ruin space missions and ruin satellites. This effects our life with technology more than we think it does. For example “If these satellites, that cost hundreds of billions of dollars, were to get struck by any tiny piece of space debris moving at the speed seven times faster than a rifle bullet, our communications could be interrupted or even permanent ally terminated.” If this were to happen, we would loose track of many things. There are over five hundred thousand objects that cause problems that only one is needed to cause.

  • Alex P

    We should be more concerned about space junk rather than putting more spacecrafts up into the sky. Putting more spacecrafts up would increase the chances of destroying an existing spacecraft, or a piece of debris hitting Earth. Shooting up more spacecrafts just makes more targets to hit in space, and more junk to hit them with. @KQEDedspace #DONOWjunk

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  • brandon delph

    brandondelphshould we be worried about space junk? my answer is yes because in the artical and picture it provides it shows over 100s of space objects that could fall out of orbit and crash to earth and take out a whole town it is not safe and we need too do somthing about it but im not sure what we should do



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