Nebulae: Crash Course Astronomy #36

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Astronomers study a lot of gorgeous things, but nebulae might be the most breathtakingly beautiful of them all. Nebulae are clouds of gas and dust in space. They can glow on their own or reflect light from nearby stars. When they glow it’s usually predominantly red from hydrogen and green from oxygen, and when they reflect and scatter light it’s from massive hot stars, so they look blue. Stars are born in some nebulae, and create new ones as they die. Some nebulae are small and dense, others can be dozens or hundreds of light years across.

Crash Course Astronomy Poster:

Table of Contents
Nebulae Are Clouds of Gas And/Or Dust 0:42
They Can Emit Light Or Reflect It 1:20
Elements Change Their Glow 3:31
Nebulae Can Create Stars 5:28

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Saturn [credit: Photo by NASA / JPL / Space Science Institute / Gordan Ugarkovic]
Carina Nebula [credit: NASA, ESA, N. Smith (University of California, Berkeley), and The Hubble Heritage Team (STScI/AURA)]
Crab Nebula [credit: ESA/Herschel/PACS/MESS Key Programme Supernova Remnant Team; NASA, ESA and Allison Loll/Jeff Hester (Arizona State University)]
Carina Jets [credit: NASA, ESA, M. Livio and the Hubble 20th Anniversary Team (STScI)]
The Twin Jet Nebula [credit: ESA/Hubble & NASA]
Tycho’s Supernova Remnant [credit: X-ray: NASA/CXC/Rutgers/K.Eriksen et al.; Optical: DSS]
Ring Nebula’s True Shape [credit: NASA, ESA, C.R. O’Dell (Vanderbilt University), and D. Thompson (Large Binocular Telescope Observatory)]
3D animation of the Orion nebula [credit: ESO/M. Kornmesser]
Stardust [credit: NASA]
From the Pleiades to the Hyades [credit: Rogelio Bernal Andreo]
How to Become a Star [credit: ESO]
The Orion Nebula [credit: ESO/Igor Chekalin]
Trapezium Cluster in the Orion Nebula [credit: K.L. Luhman (Harvard-Smithsonian Center for Astrophysics, Cambridge, Mass.); and G. Schneider, E. Young, G. Rieke, A. Cotera, H. Chen, M. Rieke, R. Thompson (Steward Observatory, University of Arizona, Tucson, Ariz.) and NASA/ESA]
PIA08656 [credit: NASA/JPL-Caltech/IRAS/H. McCallon]
Edge-On Protoplanetary Disc in the Orion Nebula [credit: Mark McCaughrean (Max-Planck-Institute for Astronomy), C. Robert O’Dell (Rice University), and NASA/ESA]
Hubble’s sharpest image of the Orion Nebula with proplyd highlights [credit: NASA, ESA, M. Robberto (Space Telescope Science Institute/ESA), the Hubble Space Telescope Orion Treasury Project Team and L. Ricci (ESO)]
Young Stellar Disks in Infrared [credit: D. Padgett (IPAC/Caltech), W. Brandner (IPAC), K. Stapelfeldt (JPL) and NASA/ESA]
The Eagle Nebula, M16 [credit: T.A.Rector (NRAO/AUI/NSF and NOAO/AURA/NSF) and B.A.Wolpa (NOAO/AURA/NSF)]
Pillars of Creation [credit: NASA, ESA, and the Hubble Heritage Team (STScI/AURA)]
Planetary Nebula HFG1 [credit: T.A. Rector (University of Alaska Anchorage) and H. Schweiker (WIYN and NOAO/AURA/NSF)]
Zooming in on the Horsehead Nebula [credit: NASA, ESA, and G. Bacon (STScI); ESO]
Orion, from Head to Toes [credit: Rogelio Andreo Bernal]
Sifting through Dust near Orion’s Belt (mouseover comparison) [credit: ESO/APEX (MPIfR/ESO/OSO)/T. Stanke et al./Igor Chekalin/Digitized Sky Survey 2]


undercoverduck says:

* watches crash course astronomy to find cool wallpapers *

nannuri Haranath says:

hey Phil, what happens when two black holes collide??

Trombonebone says:

If you can see the birth of stars in the Orion nebula, wouldn't you be watching them from 1300 years ago?

Wade Wilson says:

so basically nebulae is a huuge colloid eh?

D Chan says:

It keeps you thinking , but it is guesswork.

Jacob Bertelsen says:

So wait dust can be thick enough to block light? Or just some light?

Govinda Dasu says:

Nebulaes seem to cover much of the night sky!

B Pruett says:

I love crash course!

Brian Smith says:

The universe only reflects God's majesty.

LMAA WardogzZ says:

" The Loop is so big you could fit 25 full moons across it " Which moons could you fit across an size of at least 100 Ly ? I'm confused

Mr_Popeer9000 says:

I saw the length of the video and it was 22 minutes long, saw it again, turned into 12! WTF!!!

Nuno Teixeira says:

Phil, I love your videos…good work!

can't tell you cuz ur a stranger says:

I see Jeb, Bob, and Bill.

Owen Griffith says:

we need t-shirts and sweatshirts

The Unshaped Fawn says:

Great Episode!

Sticky Situation says:

Someone ate too many beans.

jonathanwig80 says:

so molecular clouds / giant molecular clouds and nebula are one and the same thing ?

Mileena and Scorpion Fan says:

I win because Jupiter
This only works for girls

The midnight king says:

what happens if you were to touch a nebula

PurpleBadger says:

I love space so much. <3 Thank you Phil!

Stephen Sims says:

If interstellar dust has these properties, could the red shift blamed on the Doppler effect actually be a result of blue light being scattered more than red? Could the overall redness of incoming light be blamed, in full or in part, on the intermediate dust? I know it's probably not, I'm just curious.

Robert Andersson says:

Thank you very much for making this video, Phil Plait and the rest of the crew at Crash Course Astronomy! The major three things I learned from this episode is that:

1. nebulae are very, very beautiful dust clouds and some can be seen by naked eye,
2. they glow, some due to reflecting light and others due to being hit by light emitted from a star, and that
3. these dust clouds are really, really sparse (not dense), containing about 1000 atoms per sq. m., but stand out in space do to they gigantic size.

Thank you for this video!

Saheb Panga says:

Can anyone explain how emission nebulae are formed in the first place?

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