When a huge star runs out of fuel, it can no longer support its heavy weight and it begins to collapse. As pressure from the star’s hydrogen layers push down on it, it forces the star to become smaller and smaller. Eventually the star is compressed into a tiny space — even smaller than an atom — and a black hole is born.

A black hole is not really a hole and it is not empty. It is a huge amount of mass packed into a tiny space. This mass gives the black hole very strong gravity, which allows the black hole to gobble up anything that comes near it, including stars, gas and light.

A black hole’s gravity works a bit like a vacuum. If you have ever used a vacuum, you will notice that dirt, debris and crumbs begin to move toward the vacuum as it gets close to them. A black hole’s gravity works in a similar way. As objects get close to the black hole, its extremely strong gravity begins to pull the objects toward it.

The gravity inside a black hole is so strong that even light cannot escape. Light travels faster than anything we know (186,000 miles per second!). If light cannot escape a black hole, then we can predict that nothing else can either!

174 Join the Discussion

1 Star2 Stars3 Stars4 Stars5 Stars  (99 votes, avg. 4.28 out of 5)
    • We liked learning those cool things about black holes, too, Ms. Bayko’s class! Thank you guys for checking out today’s Wonder of the Day® with us and also for letting us know what you think tomorrow’s Wonder might be about! :-)

    • Hi there, Mrs. A! Thanks for letting us know you thought the video for today’s Wonder was cool! We appreciate hearing from you! :-)

    • You’re RIGHT, Keundra! Thank you for sharing something new you learned by exploring today’s Wonder of the Day®! YOU ROCK! :-)

    • We’re not sure about that one, West! But, now you’ve got us WONDERing about it, too! Thanks for getting our Wonder brains working a little harder today! :-)

    • That’s a SUPER creative question, Hannah! We think calling black holes “pink fish” makes them sound much less ominous and scary! Thanks for making our day! :-)

    • You’ve got it, Caelah! That is the “TO” address. The “FROM” address is your own address and it goes in the upper left-hand corner of the envelope. If you have extra questions about addressing your envelope the correct way, we bet your mom or dad would be glad to help! We are EXTRA excited that we might be getting a letter from you! :-)

  1. THAT WAS AN AMAZING AND AWESOME WONDER! We think one of our students may have nominated this wonder. We want to go inside a black hole, hopefully survive, and see where it leads. Do you think black holes may lead to another galaxy or dimension? Was this a nomination? Can Black Holes be different colors? Is there any chance the Earth could get caught in a black hole? Sorry for all the questions, but this is really neat to WONDER about! Tomorrow’s wonder might be about hospitals. Thanks for getting us to wonder!

    • We LOVE all of your questions, Mr. Draper’s Class! Questions mean you’re WONDERing more about something and that is AWESOME! We’re not sure where black holes lead, but it is REALLY cool to think about. We’re also not sure if there are other colors of holes in space besides black holes, but how interesting would THAT be? We think green-and-purple-striped holes or rainbow holes (maybe with glitter sprinkles) sound a little less foreboding, don’t you?

      This Wonder of the Day® was nominated by LOTS of Wonder Friends! We have received comments from Wonder Friends in Ohio, and also from some cool dudes named Anthony and Rahul asking for a future Wonder about black holes. We also had MANY Wonder Friends submit “black holes” as a cool Wonder idea through our “nominate” link at the top of every page in Wonderopolis! :-)

    • We think you are an AWESOME Wonder Friend, Caelah! Keep on WONDERing and keep leaving us comments to let us know what you think about each day’s Wonder of the Day®, OK? :-)

  2. How did they get the footage of the black hole without being sucked into the BLACK HOLE?

    Students of Mrs. Mallen’s Class

    • A few other Wonder Friends have WONDERed the same thing, Mrs. Mallen’s Class!

      Because we share the videos for our Wonders of the Day from video library sites like You Tube and Vimeo, we don’t always know everything about how the videos were made or who made them. We were lucky this time, though, because we did a bit more WONDERing and found that the video for today’s Wonder is actually an animation! We thought it looked real, too! We guess animating that process is a lot safer than trying to shoot real video of it! We think it’s neat to find out that animators can make a video that looks so real, don’t you? :-)

    • We like that guess for tomorrow’s Wonder, “Wonder!” Way to go! Thanks for hanging out in Wonderopolis with us today and learning about black holes! :-)

    • It makes us super happy to know that you guys are WONDERing more about black holes after visiting todays’ Wonder together, Mrs. Foster’s Class! We’re not sure about whether Earth could ever get sucked into a black hole…you’ve got us WONDERing about that now, too! :-)

    • Earth can be sucked into a black hole. The more a black hole sucks in the more bigger it gets,an so does the gravity. Nothing can escape one. Does that solve you question?

  3. We think tomorrow’s wonder might be about getting stitches.

    We are glad there are no black holes near us! They’re a little scary!

    • That’s a WONDERful guess about tomorrow’s Wonder, Miss Kirsten’s Kindergarten GT Class! We think stitches would be something interesting to learn about! Thanks for letting us know you guys are glad we’re not near any black holes…because we’re REALLY glad, too! :-)

  4. We think that black holes are a really destructive part of the universe.
    We predict that tomorrow’s wonder of the day will be about stitches that you get after surgery. It might be about comedians as well.

    • We like BOTH of your guesses for tomorrow’s Wonder, Mr. Boyer! Each one would be FUN to WONDER about! Thank you for sharing your thoughts about black holes…we appreciate your comment! :-)

  5. I can’t wait to share this “wonder” with my class tomorrow. We are on a holiday today. It will be a great writing prompt for our English class first thing in the morning. Thanks for all your wonderful wonders!! My class begs me to show them everyday.

    • Your comment just made our day, Mrs. De Boer! We are so glad that your students enjoy exploring Wonderopolis! Thank you so much for encouraging them to WONDER about the world around them! :-)

    • Thanks for letting us know you liked the photo for today’s black hole Wonder of the Day®, Soccer Geek! We think that is AWESOME! :-)

    • We’re really glad you like today’s Wonder photo, Softball Geek! Thanks for sharing that with us today! :-)

    • Thanks for sharing what you think about black holes, Bryce! We appreciate you stopping by Wonderopolis and learning new things with us today! :-)

    • It makes us super happy to hear that you liked the videos for BOTH Wonders of the Day, Christian! Thank you for letting us know and THANK YOU for visiting Wonderopolis today! :-)

    • That’s AWESOME, Emily! We’re glad you stopped by today’s Wonder of the Day® and learned some new, space-related stuff with us! Thanks for being a GREAT Wonder Friend! :-)

  6. Muhaha, I’m back. Throughout the time I was gone, I was _____ and _____. That is weird, I can’t say that I was _____.

    • So, you were doing some super secret stuff, huh, Mr. Flab? We’re thankful you left us a cool comment today. We like your comments a lot! :-)

    • We think your idea for what tomorrow’s Wonder might be about ROCKS, IDKA! Thanks for sharing your thoughts with us and THANKS for checking out today’s Wonder, too! :-)

  7. An intergalactic hole in the universe that is dangerous to planets. It forms when something goes wrong and needs fixing.

    • We really appreciate you sharing your knowledge about black holes, Izzick! It’s AWESOME when Wonder Friends (like YOU!) add something special to a Wonder of the Day® by commenting what they know! :-)

    • Hi, Camille! We encourage you to explore today’s Wonder to learn more about what a black hole is…it’s REALLY cool information to learn! Have a WONDERful day! :-)

  8. That was cool because the star was trying to get away but the black hole sucked it up. (Brevan)

    I like that video because the black hole looked like it was tearing up the star. (Hannah)

    Have a great day Wonderopolis!

    • It’s SO AWESOME that you guys liked learning about black holes today, KF Dragons friends! We really liked the video for today’s Wonder, so we’re happy you did too, Brevan and Hannah! We have had a WONDERful day (thanks for wishing us one!)! We hope you ALL have a WONDERful week ahead! :-)

  9. I think tommorow’s wonder of the day is how stitches are made. I’d love to send one of my wonders that you can probably put up one day. I am 9 yrs. old. I would also like to know who started wonderopolis because I love wonderopolis!!!!!!!!!!!!!!!!!!!!!!!

    • Happy Monday, Delaney! We like your guess for tomorrow’s Wonder…it’s SUPER! Also, you can let us know what you are WONDERing about any time you like by leaving us a comment or by clicking on the “nominate” link at the top of every page in Wonderopolis! That’s where our AMAZING Wonder Friends (like YOU!) can let us know their ideas for future Wonders of the Day! We can’t wait to hear what you WONDER about!

      Oh, and Wonderopolis was created by LOTS of awesome people who wanted to share a new way to make learning FUN! Thank you for visiting today’s Wonder…we’re REALLY glad you’re here! :-)

    • That’s OK, Harker! Sometimes just being surprised with a new Wonder without having a guess about it is just as much fun as guessing! We love learning new things here in Wonderopolis and we’re glad you do, too! :-)

    • We’re so very glad to hear that, Caleb! Thanks for letting us know! We hope you had the best day ever! :-)

    • We had quite a few Wonder Friends who suggested that black holes would be something AWESOME to WONDER about, Rithik, and YES! Rahul was one of them! We LOVE getting nominations for future Wonders of the Day® from our AMAZING Wonder Friends!

    • Hello, Alexcsi! Thanks so much for letting us know you enjoyed exploring this wonder about black holes! We really appreciate your comment today! :-)

  10. I did some math and research and light is approx. 8x slower in space so, there is a very small, and we’re talking SEPTILLION PERCENTAGE small chance that light can escape black hole at normal speed.

    • Thanks for sharing about your black hole research, TyTyHM! We appreciate your comment! To think that light might actually be able to escape a black hole in space is really neat! :-)

  11. Did you guys know that the end point of a black hole is a white hole? It is like the exit point! So the only way out is to survive until the exit white hole! And did you know scientists think that our universe is at the bottom of a black hole? Isn’t that interesting?! :D

    • WOW, Abby! Thanks for sharing those SUPER SPACE-related facts! We love learning new things, too, and YES! We do think that is REALLY interesting! :-)

    • Thanks, CJ! We’re glad you liked learning about black holes with us today and also that you liked the video! Have a WONDERful day! :-)

  12. Can black holes work as a teleport for people? To go through one and end up where they want to go? I read in a book one time about that. Could that be possible?

    • We’re not sure about black hole teleportation, Tyndale, but it sure is something AMAZING to WONDER about! Thanks for sharing about the book you read and for helping us all WONDER a little bit more about black holes today! :-)

  13. Hi! Sean’s back! I loved the article. I was wondering, I know that a star has a “life”, but what happens during that “life?”

    • Thanks for letting us know you thought today’s Wonder was COOL, Asher! Did you know that we get lots of the ideas for our Wonders of the Day (including this one about black holes) from kids just like YOU? Anytime you “WONDER” about something, you can let us know by nominating your idea for a future Wonder of the Day®! Just click on the “nominate” link at the top of every page in Wonderopolis and tell us what you’re wondering about! It’s really easy and we LOVE hearing from our Wonder Friends! :-)

  14. I Loved the video. At our school, we get to use wonderoplis articles and code them, make a reflection and more. I never knew the black hole could suck up a star! That is amazing! I wonder if an astronaut has ever gotten sucked up in the black hole? I predict that if someone got sucked up in the black hole they would die. :( But, the good thing is they would go to heavan! :) This was a great wonder!
    By the way live in Texas!

    • We agree that black holes can be kind of scary when we don’t know everything there is to know about them, Mr. B. Scientists are super smart, though, and they can figure out many things about black holes without actually having to enter one. Thank you for sharing your feelings about black holes with us today! :-)

  15. That video was so epic, I would go into the black hole, do this, :O , then come back to earth and tell everyone how awesome the black hole was.
    I’m finally going into 6th grade in about 2 and a half months.
    P.S, Have you guys ever heard of a show called yu-gi-oh? It’s THE MOST EPICLY EPIC SHOW EVER! Also, have you ever heard of a game called kingdom hearts re:coded? I have it and it = awesomeness, and I beat it!!!!
    I’m a girl, btw.

    • Thanks for sharing some of the shows and games you like in your comments around Wonderopolis today, YuGiOhNinja! We also liked hearing what you would do if you went into a black hole. We like your adventurous spirit! Congratulations on doing a GREAT job in 5th grade…we’re super proud of you! :-)

    • It makes us super happy to hear that you learned something new about black holes by visiting this Wonder about them, sburt! Thanks for visiting Wonderopolis today and leaving us a cool comment! :-)

  16. I learned that black holes are real and some black holes stretch out the sun. Black holes use the sun’s gravitational pull and that’s why black holes pull everything in. Thanks for the great wonder!

  17. twenty solar mass = 3.68E17_kg/m3 for a blackhole
    ten solar mass = 1.47E18_kg/m3 for a blackhole
    five solar mass = 5.90E18_kg/m3 for a blackhole
    1.4 solar mass = 7.52E19E19_kg/m3 for a blackhole
    1.4 solar mass = 6.6E25_kg/m3 for a neutron star

    • Thanks for sharing those black hole formulas with us, nonjago336! We appreciate your comment and are super glad you stopped by Wonderopolis today! :-)

  18. That is very interesting! Today’s wonder reminds me when on two video games, there is
    a black hole when a character falls in the black hole. It is really funny to watch!

    • We appreciate your comment very much, Julie! Thank you for sharing your personal connection to this Wonder of the Day® about black holes! :-)

    • What a concise way to summarize what a Black Hole is, Alexandra! We think it’s fascinating to learn about our solar system and what happens, even if we cannot see it with our own eyes. Thanks for WONDERing about space with us! :)

  19. Hello wonderopolis, this is a great wonder but slightly wrong. It is possible for something to escape a black hole because scientists recently discovered subatomic particles called neutrons that can travel faster than light which can escape a black hole and threaten to undermine Einstein’s theroy of relativity.

    • WOHOO, you’ve been doing some STELLAR WONDERing on your own, Junior Astronomer Kid! Thanks for sharing all this great information about black holes with all of us here at Wonderopolis! We love when you have learned new things and can spread the Wonder, too! We are sending you a virtual high five for all your SUPER information and AWESOME comment! :)

    • Thanks for letting us know, Junior Astronomer Kid! We sure appreciate you sharing your thoughts and knowledge about black holes with us! We hope you have a GREAT day! :-)

    • Hi there, Wonder Friend Doggie Treat! We’re so excited that you discovered some space-related Wonders today! Keep up the great job and we hope to see you soon! :)

  20. That pic on top of the web page is fake since black holes suck in all light the don’t give off any visible light you can’t see any thing but contrary to belief black holes don’t suck in everything they give off x-ray and gamma ray radiation.

    • Great point, Wonder Friend KZP! Light is completely removed from surrounding areas when in the presence of a black hole! We appreciate your clarification with the picture, too, as it features an image of outer space! It would be difficult to find a picture of a black hole… it would be quite dark! :)

      Have a great day, Wonder Friend! :)

  21. OK out of all the fears that I have in this world, black holes is my number one fear. Luckily I never worry about it. I mean when is a black hole going to hit us? (probably in the year 4000)

    • Hey there Tyler J! We think you’re right– the chances of us encountering a black hole here on Earth are very slim, but we are glad you’re WONDERing about the cool things that take place in outer space! Nice work! :)

  22. Hi! Me again! I thought that was amazing! Here is a little fact for you!: The light from the stars we are seeing is actually light still traveling towards us! The stars that light is coming from is already dead! At least, that’s the case with MOST stars!

    • WOW, thanks so much for sharing your awesome information with us, Libby! We are so excited that you found some more information about the SUPER WONDERful galaxy! :)

    • Great question, Dan! We Wonder if you can do some more research about black holes and how long they live? We’d love to hear what you learned! :)

    • We’re glad you’re having fun, Billy Bob! We have lots of Wonders for you to enjoy… more than 700 of them! We hope you keep WONDERing about black holes on your own, too! :)

    • We Wonder if you can do some research of your own about black holes, Lara? We would LOVE to hear about all the great information you find! :)

    • We do a LOT of research at Wonderopolis, Lily! It’s fun when we can learn something new with great Wonder Friends– just like you! :)

  23. I really liked this wonder. One time I saw a TV show about black holes and it said that it would take less than a minute for the earth to get sucked up by a black hole. I also did some reasearch on wonder friend Dan’s comment. I found out that black holes can actually evaporate, but how long it takes to evaporate depends on the size of the black hole. I learned the phenomenal, extraordinary fact that even light can not escape from a black hole! One more amazing fact I learned was that a black hole’s gravity works like a vacuum. I predict that the next wonder will be “What Are Stitches?”.

    • Great work, Jamez! You’ve done a SUPER job of WONDERing about black holes– and even doing some new research of your own! Thanks so very much for sharing your comment with us! We’ll see you soon, Jamez! :)

  24. I think today’s wonder was amazing. I have always been interested in black holes but have never had the time to research it. I learned many things, for example black holes aren’t really black, they’re extremely bright. I also learned that a black hole is formed when pressure from the hydrogen layer pushes down on it, and that forces the star to become smaller and smaller until it’s the size of an atom, and a black hole is made. From my background knowledge, I knew that light cannot escape from a black hole.

    I predict that tomorrow’s wonder, wonder #796, will be about how your eyes work and how they process the images that you see. When you said “keeping an eye on you,” it made me think you’re going to talk about eyes.

    • Hey there, Colin! Thanks for joining the fun and WONDERing with us about black holes! They are very mysterious, but interesting to Wonder about! We are glad that you have been WONDERing about the science behind black holes, too! We are very proud of you for using your background knowledge to further understand the Wonder! Nice work, Colin! :)

  25. Wonderopolis,
    I never knew that a star could run out of fuel and it would make a black hole! That is amazing that even light cannot escape! It would be a conundrum if some one ran into a black hole! But, that would not be possible because it is impossible to even go out of our galaxy! I wonder when the sun will turn into a black hole… from your wonderer, Anna

    • Hi Wonder Friend Anna! We are so happy that you’re WONDERing about the formation of a black hole today! We think it’s cool to imagine all the different things that happen in outer space, it’s just so much fun to Wonder about! We hope you have an out-of-this-world day! :-)

  26. I did not know that a star formed a black hole. I thought it was just made by mother nature. I also predicted that the black hole would go on forever. I found the video and the passage to be very interesting and it makes me want to do more research.

    • That’s awesome news, Cameron! Thanks for WONDERing about the universe with us today; we hope your research goes well! Nice work! :)

  27. I thought the black hole was sort of like a tornado when it was in action. Whenever I thought of a black hole it looked black itself and I never knew it was made up of fire until I saw the video. I thought this video was very cool and so were the facts!!!

    • We’re glad you enjoyed our black hold Wonder, Tishya! Thanks for sharing your comment with us– we hope you’ll continue to WONDER on your own! :)

    • We’re so glad you enjoyed our out-of-this-world Wonder, Jackson! We can’t take credit for the Wonder video, but we sure are glad that we can Wonder about space together! Thanks for visiting us today! :)

  28. Wow that is cool I thought a black hole is like when you do not have any knowledge in a topic I learned a lot thanks a lot and I was curious on how other kids have their countries thanks.

    • Hey there, Wonder Friend Gabrielle! Thanks for sharing what you learned about black holes and outer space! We are so glad you’ve continued to Wonder with us! :)

  29. Dear wonderopolis I enjoyed this wonder. I learned that black holes can suck up stars or gas. A friend once told me that people predict black holes can bring you to a different timeline (if you survive dun, dun DUN) I think tomorrow’s wonder (Feb 23 2013) will be about cheese.

    • Hey Nick, it’s so cool that you could relate to our black hole Wonder! We’re glad you learned about the power of a black hole, and you’re guessing tomorrow’s delicious Wonder, too! In science fiction, we had heard that black holes could be a part of time travel, too! We haven’t found any scientists who can confirm that, but we will keep our ears and eyes open for more information! Thanks for visiting us, Nick! :)

    • We love your enthusiasm, Ware Family! Thanks for sharing your comment and visiting us today! HOORAY for Wonder Families like you! :)

    • We really like your enthusiasm, Brendan! Thanks for WONDERing about black holes with us today– what was your favorite part of this Wonder? :)

    • We’re so glad you enjoyed our black hole Wonder, Brysen! Thanks for visiting Wonderopolis today- we are glad you learned something new with us! :)

    • That’s great news, Wonder Friend Brysen! What was your favorite part of this out-of-this-world Wonder? :)

    • We’re glad you’ve been using your imagination with us, Beau! We would LOVE to journey into space– it would be quite the adventure! :)

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Have you ever wondered…

  • What is a black hole?
  • How does a black hole form?
  • How is a black hole like a vacuum?


Wonder Gallery

Vimeo Video star-dust_shutterstock_1774740http://www.dreamstime.com/royalty-free-stock-photo-vacuum-cleaner-nozzle-image5173325http://www.dreamstime.com/royalty-free-stock-image-black-hole-image28331466Vimeo Video

Try It Out

Today’s space-based Wonder of the Day was far out, wasn’t it? Find a friend or family member to join you on an interplanetary voyage as you check out one or more of the activities below:

  • Black holes are way too far out in space to be able to see them. But you can experience one of the forces associated with black holes up close and personal right here on Earth. What are we talking about? Gravity, of course! Check out the Defying Gravity Experiment online. With just a glass of water and piece of cardboard, you can explore the force of gravity and WONDER about whether it can be defied?
  • Black holes are like vacuums. You can experiment with vacuums at home. In fact, you might have a vacuum at home that you use to clean floors. We’re talking about the scientific vacuum, though, that means a lack of air. With the help of an adult, try out the Candle Vacuum experiment online. You’ll need a few simple items, including a candle, a match, a glass of water, a bowl and some food coloring. Have fun and make sure you get an adult to help you with this fun experiment!
  • Take some time to dream about what it would be like to see a star become a black hole. Let your imagination run wild, and then get ready to put your thoughts into words. Some people think that a black hole could be a door to another universe. Imagine you are a space traveler. The bad news is that your space ship ran out of fuel near a black hole and you were sucked in. The good news is that the black hole was just an opening for you and your crew to enter into another universe. You head to the first planet you see. Thankfully the planet is inhabited by friendly locals. It’s going to be a while before you can get back to Earth, but you can send mail home. Write a letter telling your friends and family about the planet you have discovered on the other side of the black hole. What is it called? What do the locals look like? What do they do for fun? What kind of food do they eat? What does the planet look like? When you’re done, email or send us a copy of your letter. We’d love to see it!

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