Asteroids: Crash Course Astronomy #20

Now that we’ve finished our tour of the planets, we’re headed back to the asteroid belt. Asteroids are chunks of rock, metal, or both that were once part of smallish planets but were destroyed after collisions. Most orbit the Sun between Mars and Jupiter, but some get near the Earth. The biggest, Ceres, is far smaller than the Moon but still big enough to be round and has undergone differentiation.

CORRECTION: In the episode, we say that 2010 TK7 is 800 km away. However, 2010 TK7 stays on average 150 million kilometers from Earth, but that can vary wildly.
Sorry about that!

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Chapters:
Introduction: Asteroids 00:00
What are Asteroids? 1:37
Structure of the Main Belt 2:18
Ceres's Structure 3:43
Vesta and other Main Belt Asteroids 4:38
Rubble Piles 5:16
Why did the Asteroid Belt form? 6:20
Mars-crossing, Apollo, and Aten Asteroids 7:16
Trojan Asteroids & Lagrange Points 8:25
How Asteroids Get Their Names 9:53
Review 10:41
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PHOTOS/VIDEOS

[PogieJoe]

Probably my favorite Crash Course series.
Or shall I say Ceres?

[mikeroosa]

"the universe is under no obligation to adhere to our expectations." 
that should be on a poster with like a galaxy in the background or something

[Hashishin]

Seriously no mention in the comments about how this guy has a SPACE OBJECT NAMED AFTER HIM?

[ishitagupta]

"The universe is under no obligation to adhere to our expectations" my favourite part in the whole series so far

[scottmanley]

Seems like a good place to remind people that June 30th is Asteroid Day and there'll be a bunch more asteroid themed events.

[ErnestJay]

"Don't worry, they really have a small chance to hit us"

*say that to the Dinosaur.*

[arata_]

Damn, to have your name floating around, orbiting the Sun in space is awesome! You have a pretty cool friend, Phil.

[MusiCaninesTheMusicalDogs]

So you've got an asteroid named after you!? You rock! (got it!?)

[NowanInparticular]

Why would people thumb down this video? I've been into Astronomy for about 20 years now & these videos help newer people to understand what's out there.

[alexanderquentingoldovsky]

Asteroïd : Small planet.
Planet : Big Asteroïd.

[shylywarrior]

you could say that some of the asteroids are on a .."Crash Course" :D

[anonInDE]

Everytime I'm scrolling through my Youtube feed, I'm hoping to see a new Crash Course Astronomy upload, and whenever I see one, it feels like Christmas! Keep it up!

[Freakcent]

"The universe is under no obligation to adhere to our expectations."


I love it!!

[rebelyellx]

You forgot to do a planet episode on PLUTO. :) :);)

[ashleyf]

You are one of the coolest astronomers ever. I absolutely love learning from these videos! Thank you so much for sharing your expertise and keeping science fun!

[petertimowreef]

Even though technically it's just a pebble floating in the vast nothingness of space, it's still pretty cool that it bears your name.

[joserosa]

I love watching this show. Really. Not just because I love space and planets and the unknown of the universe but because Phil seems to love these things so much that you can't help but share his excitment.

[stevebustanutinme]

One of the most beautiful, and I guess frustrating as well, is how much astronomy seems to grow; Phil Plait admits to the information he's sharing about asteroids possible being obsolete one the Dawn probe comes with information, and THAT'S beautiful. The universe isn't static, and learning is mutable.

[Gyroglle]

You really go beyond standard curriculum material. The level of some of the details you point out really stretches into BSc stuff, which is really cool. My praise is thine, keep up the good work!

[stillbleedinggreen]

I did a project in 2nd grade on the asteroid belt.  This episode is reminding me why I fell in love with astronomy.