The Oort Cloud: Crash Course Astronomy #22

Now that we’re done with the planets, asteroid belt, and comets, we’re heading to the outskirts of the solar system. Out past Neptune are vast reservoirs of icy bodies that can become comets if they get poked into the inner solar system. The Kuiper Belt is a donut shape aligned with the plane of the solar system; the scattered disk is more eccentric and is the source of short-period comets, and the Oort Cloud which surrounds the solar system out to great distances is the source of long-period comets. These bodies all probably formed closer to the Sun and got flung out to the solar system’s suburbs by gravitational interactions with the outer planets.

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Chapters:
Introduction: Where Do Comets Come From? 00:00
Kuiper Belt, Scattered Disk, and Oort Cloud 2:52
Long-Period Comets come from the Oort Cloud 4:03
Short-Period Comets come from the Scattered Disk 4:27
Pluto, Plutinos, and other Kuiper Belt Objects 4:47
Oort Cloud Objects 8:25
Review 10:38
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PHOTOS/VIDEOS
Artist's impression of a protoplanetary disk. [credit: ESO/L. Calçada - ESO]

[k]

my dad designed part of the New Horizons probe. We've been waiting for eleven years for the fly-by this summer; I remember being in high school and my dad coming in my bedroom and saying, "New Horizons has just passed Jupiter!"  and then a few years later, in college, he said, "It's passed Neptune." It's a really exciting time for us!

[bramvandenheuvel]

Science is like an addiction, the more you know, the more you want to know!

[TheOtherSteel]

You said you were going to leave Pluto alone for the moment. That was almost five years ago.

When I search for "Crash Course Astronomy Pluto" today, nothing appears.

Naughty!

[CharlieHofigan]

This is by far the best Crash Course series.

[jasonfaulkner]

5:00 - 6:05 this is the clearest explanation I have ever heard why Pluto and Neptune don't cross paths. Well done sir, thanks.

[AdamFerrari]

New horizons update: PLUTO IS BEAUTIFUL

[yaldabaoth]

"Could we be seeing an object from an alien solar system?"
2 years later.
Oumuamua: "Well, hi there!"

[psyekl]

It's fascinating to look back at these older science videos and realize all that we have learned since they were released.

[CaptNSquared]

Awww, pre-New Horizons Pluto looks so incorrect it's adorable

[katiekat]

Geez, I’m only 50 yrs old and the solar system is so different then when I went to school. There was the nine planets including pluto. But we had to memorize all the names of the moons around each planet. Which was easy because there were only a few known at the time. What ever happened to the astroid belt? When I was in school they told us that we passed through it twice a year. I think it was about 3 months apart and during that time if you went outside you would see a lot of shooting stars. That must still be there between Mars and Jupiter because how could it not be. But what I don’t understand is why it is never, ever mentioned in any videos. Why don’t they ever mention it anymore? They talk about the kiuper belt constantly which barely ever effects us. Whereas the astroid belt you can go outside and see so many shooting stars while crossing it. Is there something about the astroid belt that I don’t know about?

This younger generation and the ones after it are so lucky to have current information on everything right at there finger tips. There was a time when you were at home and if you had a question you had to hope your parents knew the answer and being that older generations are less educated you probably didn’t get an answer. Your next option was to look in a set of encyclopedias. Not many had encyclopedias in their home because they were so expensive. You had to go to the library. However, by the time you usually made a trip to the library you had already forgotten your question. Worse then that is that the information on a particular subject in the encyclopedia was maybe a half a page in bigger font then we use today with a drawing or picture on the top half. That’s not a lot of information to know about your subject. When we did little research projects for school we always had to include a newspaper article as a source. Very different from today. Today’s technology is so wonderful and amazing. I wish I could live forever to see all the knowledge and technology that is still to come. I want to know what the next unknown-unknown will be. Sort of how electricity changed the world forever. There has to be more crazy physics out there that we just haven’t stumbled upon yet that will change the world forever again. And then again and again. So amazing.

[azdgariarada]

It's strange to see this recent(ish) video that still has an artist's impression of what the surface of pluto might look like. Reminds you how awesome it is that we now have such a detailed look at the surface and that until very recently we had no idea really what it might look like.

[cidb.]

I like these episodes. They're concise and not full of weird music drowning out the narrator like so many other space docs.

[garethdean]

Aaah comets. Always knew they were something special, something.... out of the oortinary.

[ahouyearno]

This series rebooted my interest in the stars. For the first time in a decade, I waited for a clear night, went to a dark field and looked up. There's so much more to see when you know what to look for. Thanks crash course.

[dm_nimbus]

Wow, the Oort Cloud is huge! We didn't learn the scale of the solar system back when I was in school; it's incredible to think about.

[SamuraiBonesie]

I wish/hope that they either update, or make updated videos for this series

[samarman]

Here is what I think. They say the Oort cloud stretches about a light year from the sun. And our local star group are within a 10LY area, with the Centauris around 2LY away. So who is to say that say all the other stars don't have their own Oort clouds, and that all the "empty" space between stars is so empty after all? I feel that would give interstellar travel a much different realm of possability. All the possible resources, waypoints, and pathways could get us to other stars much easier.

[NichoTBE]

I find the oort cloud really interesting.. probably because there is pretty much nothing known about that region of space, infact I just did a little search and this video pretty much seems to be the most informative about the subject whereas there are lots of videos about the planets etc. I hope you can cover this subject in even more detail in the future.

[Sereosh]

Your videos are AWESOME and there's unfortunately not enough of it, keep up the great work! :)

[leminjapan]

Still my favourite CC series. Phil is an excellent educator and host!