Comets: Crash Course Astronomy #21

Рет қаралды 1,067,568

Күн бұрын

Today on Crash Course Astronomy, Phil explains comets. Comets are chunks of ice and rock that orbit the Sun. When they get near the Sun the ice turns into gas, forming the long tail, and also releases dust that forms a different tail. We’ve visited comets up close and found them to be lumpy, with vents on the surface that release the gas as ice sublimates. Eons ago, comets (and asteroids) may have brought a lot of water to Earth -- as well as the ingredients for life.
Check out the Crash Course Astronomy solar system poster here: store.dftba.com/products/crash...
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Chapters:
Introduction: Comets 00:00
Comets = Dirty Snowballs 1:19
Comets Have Two Tails 2:52
Short-Term vs Long-Term Comets 4:35
Where do comets come from? 5:06
Comets Up-Close 6:17
What Happens When Comets Hit Earth? 9:15
Review 10:59
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PHOTOS/VIDEOS
Halley's Comet, 1910 en.wikipedia.org/wiki/File:Hal... [credit: New York Times, Wikimedia Commons]
Bayeux Tapestry upload.wikimedia.org/wikipedia... [credit: Wikimedia Commons]
Comet McNaught [credit: Phil Plait]
Comet McNaught + tail en.wikipedia.org/wiki/C/2006_P... [credit: Chris North, Wikimedia Commons]
Comet surface rosetta.jpl.nasa.gov/sites/def... [credit: ESA/Rosetta/NAVCAM]
Fine structure in the comet’s jets blogs.esa.int/rosetta/2015/01/... [credit: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA]
Comet Halley apod.nasa.gov/apod/image/1001/... [credit: Halley Multicolor Camera Team, Giotto Project, ESA]
Comet McNaught solarsystem.nasa.gov/multimed... [credit: ESO]
Hubble's Last Look at Comet ISON Before Perihelion en.wikipedia.org/wiki/File:Hub...
[credit: NASA, ESA, and the Hubble Heritage Team (STScI/AURA)]
Hale-Bopp: The Great Comet of 1997 apod.nasa.gov/apod/ap131013.html [credit: Jerry Lodriguss, used with permission]
Sungrazer video svs.gsfc.nasa.gov/cgi-bin/deta... [credit: NASA's Goddard Space Flight Center]
“Large Web” graphic www.nasa.gov/sites/default/fil... [credit: JHUAPL/SwRI/Dan Durda]
Comet Daniel commons.wikimedia.org/wiki/Fil... [credit: Max Wolf, Wikimedia Commons]
Vega 1 Low Res nssdc.gsfc.nasa.gov/planetary/... [credit: Russian Academy of Sciences]
The Nucleus of Comet Halley sci.esa.int/giotto/51183-the-n... [credit: ESA/MPS]
Comet Hartley 2 en.wikipedia.org/wiki/103P/Har... [credit: NASA/JPL-Caltech/UMD]
Comet 67P/Churyumov-Gerasimenko sci.esa.int/rosetta/54472-come... [credit: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA]
OSIRIS Catches Activity in the Act blogs.esa.int/rosetta/2015/04/... [credit: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA]
Active Pit www.esa.int/spaceinimages/Imag... [credit: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA]
Depiction of Philae‍‍ '‍s planned touchdown on the comet en.wikipedia.org/wiki/Philae_(... [credit: DLR, CC-BY 3.0, Wikimedia Commons]
Colour Image of a Comet www.esa.int/spaceinimages/Imag... [credit: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA]
Comet Lovejoy en.wikipedia.org/wiki/C/2011_W... [credit: NASA/Dan Burbank]
NASA’s Stardust www.nasa.gov/images/content/36... [credit: NASA/JPL]
Comet dust www.nasa.gov/images/content/1... [credit: NASA]
Comet Lovejoy www.eso.org/public/usa/images/... [credit: ESO/G. Brammer]

Пікірлер: 524

@maelstrom57 9 жыл бұрын

I wish this show would never stop. Phil rocks!

@jonathan90881 9 жыл бұрын

melv douc Hehe "rocks"

@cortster12 9 жыл бұрын

Jonathan White He's very cool.

@INGIE32 7 жыл бұрын

melv douc If you want to see more of him watch the documentary: Curiosity: Sun storm. It's really cool.

@ashleysmall2718 9 жыл бұрын

A: Great video. 2: Thanks for the upload.

@Squoq 9 жыл бұрын

Ashley Small A, and 2? lol

@gameboo 9 жыл бұрын

Ashley Small blargh, that little detail set off an alarm in my head when he said it xD

@ashleysmall2718 9 жыл бұрын

SmogProduction 9:15

@Squoq 9 жыл бұрын

Ashley Small my bad sir.

@Mi2Lethal 9 жыл бұрын

Ashley Small That cracked me up

@aabhinnav 6 жыл бұрын

I've mentioned earlier that A: I love Crash Course and 2: Bring back Phil!

@DataCab1e 9 жыл бұрын

I foresee an entire outtakes episode of Phil trying to pronounce "67P/Churyumov-Gerasimenko."

@crashcourse 9 жыл бұрын

DataCab1e He actually nailed that one on the first take! It was more like, "Phil says it with zero problems and Nicole and Nick applaud, appropriately impressed." -Nicole

@ragnkja 9 жыл бұрын

DataCab1e Desirable difficulty. It's not unheard of for people to stumble over familiar words, rather than unfamiliar ones, when trying to pronounce a sentence that contains both.

@badastronomy 9 жыл бұрын

DataCab1e In fact, it was "Bayeux" I mispronounced.

@DataCab1e 9 жыл бұрын

I guess I'm biased on that particular one, since Pamela and Fraser over at Astronomycast are perpetually going out of their way to avoid pronouncing it at all costs.

@f0rm0r 9 жыл бұрын

DataCab1eCrashCourse He said "prognostication" and I thought he said "birdnostication". I had to look at the captions to find out what he said. I love them, thank you!

@amandawhite1422 6 жыл бұрын

I told myself, I'm going to go into the comment section and it's going to be full of A: people quoting Phil about 2: this

@MrGeekGamer 9 жыл бұрын

This is my favourite Crash Course series by far. I've even bought a telescope!

@crackrat2012 9 жыл бұрын

He said "a" and then "2".. Good job crash course xD

@McDADDyK 9 жыл бұрын

I do that too. Makes people mad XD

@mediaphile 9 жыл бұрын

I don't know where this originated, but it's the only way I make two-point lists.

@SnowWalker1 5 жыл бұрын

I noticed that too, lol.

@demonking86420 5 жыл бұрын

I do that, fite me

@radioactiveseaotter 5 жыл бұрын

@@hodzza8132 I don't have a sister to kiss But thanks

@zahincastro 9 жыл бұрын

The part on the Amino Acids found in the Coma of the Comet....Blew my mind. We might be part Alien....Awesome. This is why I watch Crash Course, Love You Guys. I feel compelled to donate right now.

@Richie_Godsil 9 жыл бұрын

When you consider that everything on earth (and in the solar system) is just remnants of material seeded through the cosmos by supernovae, yeah, we're aliens in a few different ways lol

@Bird_Dog00 9 жыл бұрын

Kevin Castro I think the theory about this is called panspermia. Doesn't answer the question about the origin of live though. If those comets carry the seeds of live, where did those seeds originate? The comets themselfes are unlikely to be the "cradle". Are those "seeds" the remnants of live from a distant solar system whose sun went nova? Can a star that is big enough to go nova have livebearing planets in the first place? Can complex orgnic structures survive not only an explosion big enough to kick rocks across the interstellar abyss but also the intense gama burst that comes with a nova? Plus, can they survive for milenia in interstellar space without breaking down?

@General12th 9 жыл бұрын

Bird_Dog Panspermia has a lot of more empirical evidence than its counterpart theory, abiogenesis, so it's more "likely" to be correct. However, panspermia suffers from a fundamental problem: if protolife molecules didn't form on Earth, then where did they come from? If protolife is so versatile that it could form inside comet nuclei, then surely it formed on Earth as well, seeing as Earth's oceans were far more hospitable than a desolate nucleus. But we can't conclude that panspermia is wholly incorrect, because we've *seen* protolife in nuclei. I believe both origins are correct, that life arose on Earth due to both random chance in the oceans and from comets on high. No, I can't support my claim. But then that leaves us wondering how we find protolife in nuclei. Glancing blows off of the Earth probably didn't happen: Earth is just too massive and has too thick of an atmosphere. There's no other surface in the solar system that could allow protolife to form. So either comet protolife *did* form inside the nucleus (in which case, amino acids and the like -- and thus life -- are extremely common in our universe) or those nuclei came from another solar system billions of years ago. If it's the latter, then protolife is surprisingly tenacious. We don't know the answers yet, but I suspect they will come in time.

@Bird_Dog00 9 жыл бұрын

***** Well, panspermia doesn't say anything about abiogenesis. Even if life did come from outer space, that life had to start somewhere. Abiogenesis just means "creation of life from non-life" and logic dictates that this happend at some point. Personaly, I find it easier to belive that life on earth originated on earth than that it surwived all the unplesantnesses neccessary to kick it our way from an other solar system.

@Qazmaxier 9 жыл бұрын

9:16 a) comets have lots of ice in them, and 2) they also get really close to Earth sometimes what's next? ɣ (gamma)?

@Gwydda 9 жыл бұрын

Qazmax I'm so going to do that from now on. A, 2, gamma. Love it already.

@bluetannery1527 9 жыл бұрын

I just noticed that and went to make a comet (LOL PUN) but you beat me to it xD

@truboo4268 9 жыл бұрын

Gwydda A, 2, gamma, pentagon, green...

@cleossleepingbed7132 9 жыл бұрын

Bryan Cotto A, 2, gamma, pentagon, green, 9, 10, 21, 3, 1, Illuminati, confirmed, LOOMNATEY CONFONFERED!!!

@truboo4268 9 жыл бұрын

ML Brand No, no, no, didn't you ever go to school? It's A, 2, gamma, pentagon, green, Capricorn, snake, dairy. DUH.

@EugeneKhutoryansky 9 жыл бұрын

Very good information. I just recently subscribed to this channel. Thanks.

@gonzesse1437 9 жыл бұрын

Welcome, Russian

@TheFireflyGrave 9 жыл бұрын

Sublimation is one of my favorite words. Just sounds so... sublime.

@Pyrex92 9 жыл бұрын

a) comets have lots of ice in them, and 2) they also get really close to Earth sometimes. LOL

@QuantumLeclerc 9 жыл бұрын

KL Havoc/Pyrex92 Was going to say this lol

@ucraznmonkey 9 жыл бұрын

KL Havoc/Pyrex92 i'm glad i scrolled down before saying the same thing. cheers, bro.

@AmpedGaming404 9 жыл бұрын

KL Havoc/Pyrex92 I was also going to say that XD

@richarddunn367 6 жыл бұрын

Every mission to a comet has not found almost any ice.

@mango5509 5 жыл бұрын

Why is that lol

@norhansabry2134 8 жыл бұрын

please do not stop making these episodes and please make more academic ones with all the math behind astronomy and all the practical work some of us really wants to learn astronomy

@Tullio238 9 жыл бұрын

I remember seeing comet Hale-Bopp in the back garden with my dad, even with all the light pollution. That's a moment I won't soon forget :)

@MaessyChan 5 жыл бұрын

So far, I have wathced 21 episode of this series in three days on my free time. I'm very new about Astronomy and I love the way Mr.Phil Plait delivered these knowledge. And also, I love his English (I'm still improving my English language too). Over all, this is the first series in youtube that I love so far. Thanks to all of the team who have created this video and share it with us!! 💕🙏

@mentpeki4345 5 жыл бұрын

I watch your wonderful videos before I sleep, hoping to dream of the stars and the universe. Of course Phil is narrating the voyage hahaha so its less scary to be in the "unknown". Phil is just so cheerful and enthusiastic that even if your about to get sucked in by a black hole he would probably have a great explanation for it, and you'll still be okay! Thank you for making videos that expands our comprehension of reality! Really deeply appreciate it. ❤🤓

@Tazfel 5 жыл бұрын

a note on the resourcefulness of this channel; not only does it showcase useful information found through internet research, but they also provide credits to the source of visual resources shown in the video. Please keep doing this CrashCourse, thank you!!!

@barnabaslee2333 6 жыл бұрын

Nice channel I wish there were more channels like this

@liamolaoghaire 9 жыл бұрын

"A. Comets have ice in them 2. Comets orbit Earth" Wait a second ....

@e.9785 8 жыл бұрын

Thanks for the Astronomy Crash Course, it's great and I really start to like astronomy more with each episode :D don't stop uploading!

@zhongzhenpronouncedassciss7060 9 жыл бұрын

Comet Sighed! **It's an Omen, The end is nigh!** Luckily we live in a more enlightened times and have comet sense

@iluvDNA100 9 жыл бұрын

Choong Zhen Cheam I was in the middle of a depression and yelled *"THE ECONOMY, FOOLS!"* **A notification flag appears** *"Warning: Your stability is low!"* **Spends 745 Administration Points**

@CharlieHofigan 9 жыл бұрын

Choong Zhen Cheam Better sacrifice a human heart just to be sure.

@iluvDNA100 9 жыл бұрын

Did you guys just totally miss the referencefest?

@Edit-nk6nb 9 жыл бұрын

Choong Zhen Cheam Needs more Natural Scientists

@NeroPiroman 9 жыл бұрын

Joe Seph eu4

@p0wers1ave 9 жыл бұрын

"...what gets me are the philosophical ramiications of this. When we look into space, when we examine our celestial neighbours, when we send probes, we are looking at our own origins". Just brilliant Phil!!

@ryu3180 9 жыл бұрын

Phil is my hero. No, really, he makes astronomy fun and approachable!

@rahuls2111 6 жыл бұрын

Loved the crash course. Thanks heaps Phil & team 🖖

@whichdoktor 9 жыл бұрын

I began this series not really liking Phil, main because he wasn't Hank. But I stuck with it because I love astronomy, and 'lo and behold! I actually started seeing more of Phil's enthusiasm and it started rubbing off on me more. I am now in orbit around Phil. Please make more videos like this (especially college-level stuff). Sincerely, A happy fan

@kihiable 5 жыл бұрын

Its re

@Ritermann 9 жыл бұрын

What I like about this channel is, that you care about design. It just feels good to watch it! Thanks for putting effort into it.

@dhoffheimerj 4 жыл бұрын

I love Phil Plait and his course.

@ganaraminukshuk0 9 жыл бұрын

Wait, A and 2wo? What number system is that? lol

@McDADDyK 9 жыл бұрын

The best I do that too

@laughlinflyer 7 жыл бұрын

Too funny! I use that one myself to see if anyone's listening!

@BadassPlaya-rm4on 5 жыл бұрын

Card numbers for poker

@josephbuckreis3212 9 жыл бұрын

This is my favorite crash course series

@kiriau 9 жыл бұрын

Hey there. I'm really enjoying this series of Crash Course in Astronomy. Presentation by Phil is fun, exciting and engaging. Overall presentation, graphics etc, really makes this series a joy to watch and learning about the stars, planets, earth, even the building blocks of life on earth, actually cool. Keep up the good work Phil and co. Thanks team

@LawffleCopter 9 жыл бұрын

A: Comets have lots of ice in them and, 2: They also get really close to Earth sometimes. A and 2? Solid.

@McDADDyK 9 жыл бұрын

I do that too

@grynnrosas6362 8 жыл бұрын

Thank you CrashCourse! This channel helped me a lot!

@Titapias 9 жыл бұрын

I love you team Crash Course! Thank you a million times for such an amazing job. 😊

@CraftyF0X 9 жыл бұрын

Upcoming Kuiper belt and Oort cloud episodes confirmed ! Btw this CC show is so good, and Phil is so enthusiastic, entertaining and cool that I could watch 2-3 episodes like this a day.

@blaahster2174 6 жыл бұрын

Thank you Phil for all these awesome videos, you taught me a lot!

@wjeverett 4 жыл бұрын

The Great Daylight comet of 1910 showed up right before Halley's. They thought the Daylight Comet was Hailleys. It wasn't but the former was so bright people thought it was going to hit us. This is the comet of the movie "The Omen".

@roshaan 9 жыл бұрын

Well done Dr Phil Plait and I loved the last part which mentioned the fact that amino acids were present in the coma.

@erickcapitanio1957 9 жыл бұрын

7:39 "inhomogeneous"? so, heterogeneous?

@Petey0707 9 жыл бұрын

Favorite series so far! Loving it.

@ju44_0 8 жыл бұрын

Thank God we live in such enlightened times.

@TheDajamster 9 жыл бұрын

Excellent episode!! This one ranks up there with the one explaining exactly why/how the "Tides go in, Tides go out."

@ivanchagasp 9 жыл бұрын

It just keeps getting better and better! Thanks a lot... I mean, A LOT, thought cafe team, Phil and Crash Course team!

@a.henderson9559 4 жыл бұрын

MIND BLOWN

@sohee7597 4 жыл бұрын

I can't believe we can get this gem videos for free

@RorshachDesk 9 жыл бұрын

this is my new favorite series!

@YongeDundasSquared 4 жыл бұрын

Love this Video!

@steveandrews5307 Жыл бұрын

very informative, keep them coming please.

@davidortega264 5 жыл бұрын

We all want a crashcourse about space exploration c: don't we?

@jubeeajwee 8 жыл бұрын

These videos are amazing!!

@kaiserredgamer8943 5 жыл бұрын

The comets' orbits get longer every perihelion because outgassing is like a natural thruster burn. Because of the Oberth Effect, their aphelions get higher, eventually reaching escape velocity.

@FatmasterKY3 9 жыл бұрын

Excellent, really enjoyed this one

@shawnm4842 9 жыл бұрын

this is a fantastic series

@DarthMartik 9 жыл бұрын

This was an exceptional video, as usual. How do comets actually become comets though? What sets them on their incredibly high speed and large orbits?

@Lemurianlemur 8 жыл бұрын

I'm so impressed Phil managed to say Churyumov-Gerasimenko. I was actually curious about how it was pronounced because my poor astrogeology professor wouldn't even try, haha!

@b.sharp. 4 жыл бұрын

Here's a list of the comments on this video: A) people praising Phil because he's awesome 2) people complaining that he said A then 2 in his list at the end

@Pythos_Sapunov 9 жыл бұрын

I see at least Jeb is enjoying the show, Bill and Bob seem to be concerned if their next rocket is going to fall apart on the pad!

@jonathanmcvay2744 9 жыл бұрын

I cant believe that I shunned this guy on episode 1 and iv been hooked ever since keep up all the good work this has been a fantastic series

@ormanvidal 9 жыл бұрын

Great video. Thank you very much.

@JackSteadlan 9 жыл бұрын

Great episode

@narayanannagarajan508 6 жыл бұрын

Excellent Video, Thanks!

@andreshuertas7122 9 жыл бұрын

Great subject.

@ptxaholic 9 жыл бұрын

Comet: I'm not fat, I'm fluffy. ***** *swoon* ;)

@SleevesYT 4 жыл бұрын

Its time to say hello....

@jamesdahmer5027 9 жыл бұрын

MORE FASTER PLEASE AND THANK YOU THIS IS ROCKING MY WORLD.

@RusticKey 9 жыл бұрын

Panspermia... Every time I hear something that reminds me to that theory, it gives me chills.

@mateoo612 9 жыл бұрын

Perfect like every other video!

@kstareas2838 5 жыл бұрын

very good

@andrewreyna376 6 жыл бұрын

OMG!!!! i barely noticed that this series does not have Thought Bubble.

@babis8142 9 жыл бұрын

fascinating

@PaulTeichman 9 жыл бұрын

Love the Show and the Kerbals :D

@viktornerlander1409 9 жыл бұрын

God damn it this episode was so cool. Thank you, Phil.

@patrickmulvany2949 4 жыл бұрын

Amazing video buds

@xevious1538 9 жыл бұрын

Great episode :)

@angelluisll1033 Жыл бұрын

Greate starter video.

@Pile_of_carbon 9 жыл бұрын

Got to love Crash Course Astronomy. Space is a fascinating place. =D

@usamarajput3980 7 жыл бұрын

suxh a informative lecture :) thanks sir

@ohsosmooth01 7 жыл бұрын

I wonder if those "jets of gas streaming away..." are strong enough in themselves to alter the course of the comet?

@RaNdOmIzEd2017 7 жыл бұрын

as soon as he said "a" and then "2" i immediately paused the video to see how many people mentioned it in the comments

@wjeverett 4 жыл бұрын

They are expecting a comet the size of Jupiter according to guest on Coast to Coast.

@Tyloric 9 жыл бұрын

I could listen to Phil's voice all day. :o Narrate my life, pls

@azathothic 8 жыл бұрын

Love that rubber ducky sound added.

@wietsevandewalle5098 9 жыл бұрын

Love how Phil looks when he says 'that means some life on earth is alien' just that look XD!

@bradyburnsides387 9 жыл бұрын

Hey Phil I love this series! I've always been interested in space and astronomy but until late I've wanted to be a mechanical engineer. This fall I'm starting my senior year in HS, so I don't have much time left to nail down a major and a school choice! What did you study? What would you recommend? I'm looking at aeronautical engineering but I'm not sure if that's a viable choice since j really want to be up close and personable with these kind of discoveries! Thoughts?

@TanKLoveR 9 жыл бұрын

Was I the only one who spotted the A Flock of Seagulls haircut on the scientists at 6:33? Very 80's and very appropriate for the video.

@quinnnichols4788 6 жыл бұрын

Great Video For School Crash Course Earned My Sub

@exceptionalish614 9 жыл бұрын

"A [...], and 2 [...]" Thank you for that. :D

@kstareas2838 5 жыл бұрын

cool video

@Pillowcase 9 жыл бұрын

a) and 2)

@layzuchiha5278 4 жыл бұрын

awesome! u're so pro

@leestuurmans2837 9 жыл бұрын

this is the best

@tenaciousdean6179 9 жыл бұрын

Not 4 days removed from Sixth Form and I'm already reminded of my A2s

@webdevvy 9 жыл бұрын

Loving the kerbals on the desk :D

@ryankakkar1542 7 жыл бұрын

Congratulations

@SnowWalker1 5 жыл бұрын

Here's my question. Why do the comet's frozen particles never completely evaporate? Or do they but then replenish themselves when out in the frozen farthest reaches again?

@Decrosion 5 жыл бұрын

SnowWalker lol replenish haha. srsly tho its a good question. a) any scienticians care to comment? 2) also why did the rosetta probe capture complex materials that could not have come from a theoretical oort cloud? for example the presence of larger than expected fragments that far outweighs the aniticipated ratio of spacedust and comprised of different materials which requires selective heating, and suggest vulcanism?

@wolfgangamadeusmozart2622 9 жыл бұрын

Please do a video on quasars!

@BenPrindle 9 жыл бұрын

You're the best!

@braecoates9101 7 жыл бұрын

good vid

@dimension2788 Жыл бұрын

Nice one Phil. Wondering about the earth temporarily capturing a orbiting comet such as in Worlds In Collision. Could it rain petrol from the methane in it.

@Angelboor 9 жыл бұрын

Once I was at the beach at night with a friend looking at the stars when we started noticing a lot of comets, but what shock us the most was that not all of them seem to follow a particular orbit. They were moving in zigzag, turning, in circles it was nuts. Up to this day we're still not sure at what we were looking. It was totally amazing. Phil didn't mention anything in the video, though...