The Most Habitable Places for Life in Space

What does it really take for a planet to be habitable for life? It turns out, certain parts of a star system, a galaxy, and even the universe as we know it, are more habitable than others. Get to know them as Hank takes you on a tour of some of the 'nicest neighborhoods in space' in this new episode of SciShow!
This will be the last video covering a space related topic on this channel! For more videos about space featuring Hank and our new hosts, head over to:
/ scishowspace
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Sources:
www.solstation.com/planets/wat...
kencroswell.com/RedDwarfActivi...
news.discovery.com/earth/what-...
imagine.gsfc.nasa.gov/docs/ask...
www.astro.caltech.edu/~george/...
solar-center.stanford.edu/FAQ/...
www.space.com/15341-planet-for...
hyperphysics.phy-astr.gsu.edu/...
members.nova.org/~sol/solcom/x...
www.enchantedlearning.com/subj...
sciencepenguin.com/orion-arm/
scitechdaily.com/astrophysicis...
burro.astr.cwru.edu/Academics/...
csep10.phys.utk.edu/astr162/le...

[@joeyenochs9469]

I absolutely love Hank dramatic swing as he faces the screen when he said "FALSE!"

[@hotypant123]

Right?

[@sabrepaw]

Don't you mean faces the camera?! :D :D :D

[@hannahaugustyniak11]

Joey Enochs it makes him look like the 10th doctor

[@jackmcnaughton2038]

Joey Enochs he

[@andressigalat602]

I'd say he looks more like the eleventh, Matt Smith, he was the one that, paraphrasing John Hurt's War Doctor, couldn`t speak without flapping his hands around. He even sounds a little bit like him.

[@baowolf0011]

"space excitement is terrible" just fantastic.

[@danielhale1]

I love the silly, conflicting ways that Hank describes the universe. Nice, safe supermassive black holes don't come up in normal conversation. :D It makes learning fun, and I remember long after.

[@glenn2687]

+Daniel Hale i swear when cloning humans becomes real the first person i'd want cloned is hank then all the clones will be sent out to schools everywhere so that he could be the best teacher everywhere. i just realized how creepy this sounds.

[@stuartmacleod8225]

+Mica Santos However, since a large portion of your personality is determined by life expiriences, a lot of the clones could be terrible teachers. They would look the same, but would not be the same Hank.

[@lonestarr1490]

@@stuartmacleod8225 Therefore, we train them all in VR by letting them live the life of Hank up to this point (you know, like in that one episode of Rick & Morty).

[@Krystalcove]

I don't know if it's more terrifying or reassuring that black holes are actually relatively safe...

[@lonestarr1490]

Definitely terrifying. Space is an insanely huge pile of nothingness sprinkled with all sorts of ludicrously powerful incarnations of death and destruction.

[@AkaiAzul]

Reassuring. Your ancestors have lived over hundreds of millions of years, and your descendents (assuming you get some) are likely to continue existing for several million years.

[@vinnielalumia]

Why would it be more terrifying? That doesn’t make sense

[@Daruqe]

"You were probably taught that the Sun is a typical star. FALSE!" THANK YOU. You are literally the first person I've heard besides my astronomy professor say that.

[@TheMarshmellowfellow]

I'm a n00b and thought that... sup. We are soooo lucky to be placed where we are in the galaxy; YET we take it all for granted. We monetize almost everything possible, murder innocents in the name of defense/resources, lock people up for smoking a harmless plant that provokes laughter- not violence, hold onto a book that supposedly speaks of God's rules and teachings but then you realize that all wars tend to start with difference in God(s) *I.E.* Guy1: Do you accept the Lord Jesus Christ as your Lord and savior? Guy2: I really can't, it's not in my culture- **Guy1 slits Guy2s throat** I really hope we one day have a chance to prove ourselves but it can't happen with everyone stuck to a screen, learning ignorance in massive doses. I at least take solace that there may be a world out there that is living in harmony. Billions of stars in our galaxy alone- there has to a world without war... I hope... that would suck if there isn't a utopia planet out there.

[@seanm7445]

I do hate it when my toddler emits deadly radiation.

[@mymyrrah]

I hate it when my little brother emits nuclear radiation and oozes nuclear waste.

[@goravm1365]

I know it's soo annoying

[@blackoak4978]

I think u mean *eminations* ☣😂

[@DocWolph]

Jack Jack Parr.

[@vifurawa2715]

Cryzyra Chaneco Lmao, but they just made a joke. I'm Filipino too, and I understand what karma means.

[@natep276]

The Sun is not a regular sized star? MY WHOLE LIFE IS A LIE!!! (I still liked the Hunger Games and Spongebob references) :)

[@ArmoredCricket]

People every time: These places are inhabitable. Life: Hold my beer.

[@TheEmolano]

Life can live everywhere, the question is where can it begin?

[@TheGuyWhoIsSitting]

I hope we figure out if we're not alone in the universe before I die.

[@xxbighotshotxx]

Me too!

[@Fabelaz]

Well, that's not a fast process.... But, just don't die tomorrow, k? And I actually hope that there still will be humanity on earth when I die...

[@9Mystere9]

Дмитрий Дронов I'd say your odds are about 7 billion to one(or better!)

[@Fabelaz]

9Mystere9 well, we have 2 big kids playing...

[@TheDSSlayer]

well since the scientists in our generation has discovered more then ever in the past century alone, i'd definitely think we got a good chance of sci technology to find other organisms out there! :)

[@slaughtz]

This episode just makes me appreciate life more.

[@jacobwebb8818]

I'm the only one in my family who finds science to be really enjoyable. I find it FASCINATING while my family is just like oh cool

[@timothyratedr4141]

me two

[@SkittleflakeKitty]

ikr?

[@sebastiansalve8753]

Same here

[@charlieplays8952]

Same with me

[@michaelcoulter1114]

Me too 😃

[@Michellelynn003]

Like Panem, or Michigan.. Haha

[@Adamas97]

This was an amazing video. So much information creatively presented.

[@BattleBunny1979]

I always love this stuff. I follow the planet discoveries with more interest than the general news.

[@bobjones4469]

Of course Earth is "perfect" for us, we were evolved to thrive on it. If there is life in other places in the universe who evolved to thrive in different conditions (in fact, such instances exist here on Earth), they would complain that the Earth is too hot or too cold for them.

[@physsnake]

+Bob Jones You're right. Those filthy humans that always think about themselves. What a selfish alien race.

[@physsnake]

+Bob Jones You're right. Those filthy humans that always think about themselves. What a selfish alien race.

[@farklemybrainsout]

+Bob Jones you dont have very much complex life forming in those volatile areas of earth. so its safe to assume that that if a planet was only all of those not so perfect areas, complex life would have a hard time forming.

[@astronomyguy976]

+Olivér Tabbouch just a theory, how fucking dumb Are You. Tell me how it was disproven, and while you're at it give me proof of god and Jesus remember the bible isn't proof GOOO

[@kierankincaid4581]

+Olivér Tabbouch the bible was written by people, it could have been illusions or people could have made it up for fame, you can't say that every human tells the truth, can you

[@SparkySywer]

I don't want to be caught dead anywhere, because then I'd be dead.

[@BSKX17]

Amazing video, SciSchow. Hank's presentation is at least half the greatness.

[@angelic8632002]

Great episode!

[@poppingatz3839]

Keplar 62E must have some fucking scary alien sea monsters if the whole planet is water.... yiiikes

[@poppingatz3839]

alien megladons n shiit FKK DAAAT

[@dandremcgee1407]

imagine it-_-

[@dandremcgee1407]

zammmmmmmmmmmmmmmmmmmmM

[@cadebronson8949]

Poppin Gatz I think that's the playing it at subnautica is based off of

[@BikesOmega]

The theory that life can only exist on a rocky planet with a perfect amount of water such as ours only assumes that all life must be similar to Earth's. This is kind of unreasonable because any life separate from ours would be alien and completely different and could live under its own unique conditions.

[@AvWorgen]

the only thing that keeps us as an intelligent species and all that is because we are highly adaptive but we cant say that for planets to have life they need to have water and land and air and something to breathe there's probably aliens that use deadly gasses like we breathe and they probably dont need water to live because every lifeform should be able to adapt or else our universe is very weird

[@hxhxhgfd]

Granted, life could be very different from what we know, but so far earth life is the only kind we know exists and how to identify. It makes sense to look for earth like life first, because the only conditions we currently KNOW life could form in would be earth like conditions. With that set of criteria, it makes sense to (at least for now) look for planets that are earth like.

[@QuantumSeanyGlass]

The thing is, though, we aren't looking for life, we're looking for habitable planets, which we can live on. 2 quite different sets of criteria.

[@AvWorgen]

QuantumSeanyGlass here's a question then... if we are not looking for life and are just looking for habitable planets how are we going to get our food? i dont know about you but i would atleast find a planet with life and then find out if the lifeforms is edible then see if its a habitable planet because i dont think it will be that easy to transport food if we already have food problems still today so we either need quick transports or we need a very small population on the planet and let them live as cannibals

[@BadAssAwsomeness]

True life on another planet could have adapted to only live in water or to use some other type of gas besides oxygen to survive. But even finding planets like that can be difficult. Even the most simple and robust forms of life we have found could not survive the high levels of radiations found in most of the universe. Not to mention constant meteor strikes and temperature changes would make it impossible for life to evolve any further than single celled organisms.

[@thejerrymobile]

Why would we discount water worlds from the possibility of civilization? That's... That's geocentric! :P Seriously though, odds are that if we find life, it won't be life as we know it.

[@BigFella69]

And why not?

[@MadeinHell2]

There is one main reason people don't consider water worlds capable of harbouring civilization (not life, civilization, life is more than welcome there). It is really, like REALLY hard to make tools underwater. Not only is it an amazingly destructive and makes construction many times harder than on the good old solid ground. It also has a nasty tendency of making it nigh impossible to forge anything. You know how smiths toss those red hot iron bars into a bucket of water right after working with them? Now imagine the bucket of water is CONSTANTLY SURROUNDING YOU. Maybe some form of sci-fi organic-tech based civilisation might arise from oceans. But as far as we can tell. If anything intelligent ever grew up in the oceans, they would not have tools and probably would have stable housing. They wouldn't have writing and thus they wouldn't have civilization.

[@thejerrymobile]

You make valid points, but I was thinking more in terms of supporting alien life than being habitable by humans...

[@MadeinHell2]

thejerrymobile I wasn't talking about humans.

[@thejerrymobile]

MadeinHell2 I hadn't seen your comment. In response to your comment, it is an interesting rationale. It only proves that the possibility of forging would not be considered by any advanced hypothetical lifeforms. Given that we don't really have any evidence to go on here, I don't really have a counterargument beyond that.

[@Adam-qy6yc]

"Like Panem... Or, Michigan." As a resident of Detroit, I can confirm this analogy.

[@yarp1246]

Hank, I adore you. These are the best science/space-related videos I have ever come across, aside from Vsauce's. Thank you so much for making my days better by giving me mini doses of science-filled information. I think you're my favourite KZbinr.

[@daisyhinojosa23]

I wish this guy was my science teacher

[@hirodnazari2720]

Hey, De-Von Ambitious I wish you would shut up.

[@DeVonAmbitious]

Hirod Nazari Chill out a was joking with the woman not you.

[@iknowthings7367]

One of the best episodes of scishow ever! Funny & jam-packed with interesting!

[@octapusxft]

Maybe this video could make some people understand how precious and unique Earth is.

[@InterestingTed]

Agreed, I really like earth.

[@Broontroon]

but what if that keplar planet has fishies?

[@goodcolimgpu10]

crabsnake for lunch?

[@alecnolastname4362]

@@goodcolimgpu10 Yea because drastically manipulating and hunting new species to near extinction has worked out well for us.

[@EvolQ]

Because one luncheon puts an entire species at the brink of extinction

[@lucienpetersen9010]

Fishies!!!

[@MGSLurmey]

@@alecnolastname4362 Do you know what a crabsnake is? XD

[@free_spirit1]

Scischow! Hank! how about an episode about post traumatic stress disorder? Also, you still haven't done one about lysergic acid!

[@prankfiles]

In space?

[@free_spirit1]

***** YES!

[@symbolxchannel]

Why isn't this in Scishow Space?

[@Murdocisgod83]

Thumbs up! They make the channel and then don't post this video there? Perhaps they should explain if they plan to move all these videos at some point or whatever.

[@EkiAku]

I don't follow scishow space so I like some space on my regular scishow

[@charlie-cacticrafts1457]

If you read the description it says this is the last space video on this channel and from here forward space related videos will be on the other channel :)

[@EkiAku]

Charlotte Fryer ...aw I'm disappointed. >:

[@lordelliott42]

Charlotte Fryer You'd think they'd take this opportunity to promote the new channel one last time.

[@docopoper]

Wow, this was a really interesting video.

[@tojin666]

hey guys, love your show. the way you explain things is such a nice simple way, even throwing in some comedy (thank you Hank you always make me chuckle). Even my friend are picking up some of the stuff you talk about.

[@cophezzeslangin2794]

Channel is awesome, thank you guys for putting all of this info out for all of us

[@zekky1000]

I loved how you said false xD

[@Dharcnesss]

isnt this more material for SciShowSpace?

[@Sylrissa]

Was just thinking the same thing

[@BeatleFloydZeppelin]

Sometimes KZbin channels create a video weeks in advance, and upload it as a private video. Then, they make the video public when it is scheduled to be released. I am not entirely sure, but that could be what happened here.

[@TheSlepca018]

its better this way :)

[@ashablue78]

This was so cool! thanks for sharing your knowledge!!!

[@tomhamilton5707]

Fascinating and awesome as always Hank - thank you!

[@ewan.cartwright]

why wasn't this on SciShowSpace?

[@JellybellyWaffles]

I kind of thought SciShowSpace was made for these types of videos.

[@ewan.cartwright]

JellybellyWaffles exactly

[@manumercuri7207]

Let the conspiracy begin!!!

[@xxmastaxx21]

"This will be the last video covering a space related topic on this channel!" Which is immediately followed by a link to scishowspace. or so says the Description.

[@manumercuri7207]

People never read... Thats why KZbin is so popular! (Im also people)

[@LucysCorsetry]

Can Hank (or someone) explain how radiation is emitted from black holes when other forms of electromagnet radiation (e.g. visible light) can't escape beyond event horizon?

[@antivanti]

The radiation doesn't come from the black hole itself but from the matter which falls into it that gets accelerated to close to the speed of light as it spirals towards the black hole. I'm not sure about the exact mechanics but the important part to understand is that the radiation doesn't come from inside the event horizon (or apparent horizon.)

[@rockjohnson6610]

Do not question the black hole, sir. It defies logic.

[@uzimachi1]

The pull of the black hole is so radical that the stuff that spins just before the event horizon sometimes is tossed out at great speed. It's gravitational influence doesn't begin at the event horizon, but much earlier than that. Someone correct me if I'm wrong in that xD

[@krishanbansalphotos]

It's called "Hawking Radiation". Black holes emit a type of perfect black body radiation due to odd quantum effects.

[@antivanti]

krishan bansal Black holes do emit hawking radiation but that is extremely faint and not the cause behind quasars.

[@jeroenstrompf5064]

Amazing communication! Wonderful video!

[@ucigucimuci]

great one as always, thanks

[@Zubinrube]

Bro, you don't understand. I need my cheetahs and sunflowers. I NEED THEM. O.O

[@ToastyBoy17]

Jaguars and moonflowers are better.

[@qhack]

Is there some reason why this isn't on SciShow Space?

[@DaveBry]

I wondered that too, because I only saw the title in my inbox. Maybe they filmed it before SciShow Space launched, but why not release it on that channel?

[@mayamadolyn]

Nothing like a space video to make you feel truly special and insignificant at the exact same time.

[@twentylush]

I wonder who our father star was. What old star sacrificed it's own solar system to give birth to a life bearing planet.

[@tiffles3890]

+ZX Spectrum Gives you chills that he tore his planets and himself inside out, and its his remains that we eat, shit, bleed and spit.

[@javige03]

could explain rogue planets

[@LaineyBug2020]

Helios

[@LydiaXavier321]

Imagine if we went to Kepler-62E and found Admiral Ackbar.

[@carlw]

That's funny!

[@adam3609]

dont go... IT'S A TRAP

[@SensicalOxymoron]

Kepler 62-E is Kamino. Duh.

[@TheCosmosWins]

yes ^^^^

[@lucasgitzen2683]

This was one of the most succinct, organized, funny, and witty videos I've seen from SciShow. Highly informative and very entertaining!

[@bethjones3390]

This sci show episode was awesome!!! Please do more like this!

[@shakey215]

girls are about 26,000 light years away from my central bulge too...

[@brusquebuttrue589]

But are you into big black holes?

[@vip1691]

BrusqueButTrue He definitely has at least one.

[@L3xCin]

+Sotiris Krol You could say it's pretty 'holy'

[@JoeGP]

hey shouldn't this have been on the SciShow Space channel ?

[@HendoGaming90]

Awesome episode. Keep up the great work team Scishow.

[@TheBaldingPied]

as someone living in Michigan, I can agree with you.

[@mickeyj4996]

I don't know why the intro reminds me of Kim possible

[@MikhaelAhava]

What's it? Sounds familiar though

[@robinchesterfield42]

Oh, it does! Now that you mention it. The notes are similar to her "Kimmunicator" ringtone--not quite the same, but close. That's probably what's doing it. :)

[@SeanLumly]

As informative (and fun!) as this video was, I'm very sceptical about concrete claims of things that we don't yet know. Certainly the claims of what would constitute a nice 'neighbourhood' in space apply to life _as we know it_, but if history as taught us anything (even on this lonely planet), is that life is diverse and unpredictable. What if there were other forms of life than [earth] DNA based life? What if there was life that thrived in those hellish conditions mentioned? What if our time-scale of what constitutes a successful eco-system is wildly different than what potentially exists? What if our spatial scale of what a living-creature is, is infinitesimal? Not only would these questions make for a very interesting science fiction story, they also remind us to stop assuming that Earth holds a monopoly on life in the universe. As such, as we search the cosmos for neighbours, we should not restrict ourselves to looking for mirrors.

[@SeanLumly]

I'm not criticizing what we are doing in searching for life, and assessing the likelihood of its existence in various regions. Not by a long shot: I earnestly and enthusiastically support the impressive endeavours that are currently being undertaken. My argument is simply that it should be clear that we are looking for "life as we know it," considering we know next to nothing about what life may be in the universe.

[@colinprevatt9439]

Indeed, while I think your speculation is interesting and there may be other 'forms' of life that aren't based on DNA (for example 'life' based on pure energy in certain sci-fi films), you have to consider the evidence of the knowledge based on what we do know. Life works because carbon is a very versatile material, having four available electron positions (Hank actually does a video about carbon in regards to life on scishow). This allows for many configurations that are essential to life as we know it, although I have heard speculation that maybe life could be silicon based because of its similar valence of four. That aside though, you have to consider temperature as well. We have forms of life on earth that are adapted to very cold temperatures and very hot temperatures (or moderate temperatures like most macro-oranisms) but evidence suggests that they can't be adapted to both. Planets with wildly fluctuating temperatures probably would not be able to support life based on this. Lastly, you should take into consideration temperature limits in regards to chemical bonds. Even if something was not dna based, it would still have to deal with radiation and extreme heat breaking down the structure of their bodies. Okay maybe I got carried away and keep in mind I am also just speculating myself, but I think scientifically speaking 23 need to do research based on evidence of things we know instead of things we cannot yet fathom, and maybe later down the road perhaps other possibilities may be understandable.

[@Othelbark]

"...remind us to stop assuming that Earth holds a monopoly on life in the universe." I'd just like to note that I don't know *anyone* who holds that assumption and I've never heard it expressed. I'm sure they exist but most people I know (myself included) actually assume the opposite based on the sheer enormity of the universe.

[@phyrath5]

Colin Prevatt There is a possibility that a life form based on Dark Matter could exist (it does make up more of the universe then normal matter). As Dark Matter doesn't seem to be affected by normal matter things like radiation might not be a concern for Dark Matter based life forms. Aside from that I pretty much agree with your comment.

[@NaZaRK3]

"Certainly the claims of what would constitute a nice 'neighbourhood' in space apply to life as we know it, but if history as taught us anything (even on this lonely planet), is that life is diverse and unpredictable." People who do this shit for life are aware of this, and i doubt you are aware of how dangerous the universe is for life, fortunately the universe is HUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUGE so life elsewhere than our solar system is very very very likely

[@jonn_mace_80_95_]

Great informative knowledge of some aspects on how our universe works.

[@strimer9]

I love SciShow. Thanks so much for everything you're teaching me.

[@schnapps77]

Isn't there a possibility that life elsewhere could be different in terms of what it needs to form and survive? Like we need oxygen, carbon, water, sunlight, etc. But life elsewhere in the universe could need only some or none of those things and could be completely different than we think.

[@TheSapientity]

Yes, but since we know how our sort of life works, we roughly know what hints to look for on other planets. Sure, there could be completely different forms of life out there, but would we really recognize it as such? I think that's how it works, I could be completely wrong.

[@TicTacMentheDouce]

We can't really know that, there are theories that there could maybe be life based on things like silicium or other close elements, But for what we know, those have lots of inconvenients compared to carbon, and we can't say for sure that it can exist. And I think it is worth mentionning that it is a lot more easier to look for something you know exists here and works, than something you don't know anything about :p

[@Novenae_CCG]

I dunno why oxygen, carbon and sunlight is so important (well, sunlight provides energy, of course. And you need energy to be alive), but water is a universal solvant. It's a unique element, in that it allows for many chemical reactions to take place, which don't happen in other substances, which is why water is a great place to look for life. EDIT: Water is also a very simple molecule, only requiring two hydrogen atoms (most of the matter in the universe is hydrogen) and 1 oxygen. And I remembered why carbon is good: It reacts very well with lots of different elements, giving it a significant advantage over other elements.

[@gabeat_]

The person who could discover an alternate evolution pathway would win an award named after them. Like Alfred Nobel.

[@bregorforgett4983]

Samuel Gabites Alfred Nobel didn't win some competition to have the Nobel prizes named after him. He was disgusted with what he did with his life, and with what people though of him (which he learned from an accidental early obituary post). He left most of his estate to CREATE the Nobel prizes.

[@s3blastois3]

We could make Atlantis in Kepler-62E, and make a FF7-like colony there.

[@s3blastois3]

By FF7, I meant that one place down underwater, where you played the submarine game.

[@ItoeKobayashi]

This was a very informative video! I learned a lot of interesting stuff! Thanks :D

[@fistmypenguin]

So nice to hear smart happy people who are passionate about the world, life, and everything!

[@nocapsallcaps9908]

Nice vid SciShow I was playing KSP while watching this...

[@tjgordon5]

NOCAPSallcaps- One of the more clever usernames I've seen. I'm a fan haha.

[@AnyOtherNamePlease]

I would love an update video!! :)

[@CADOIP]

AnyOtherNamePlease yup

[@jackmead7292]

Hank is one of the most entertaining science-internet-tainers ever

[@TRAVELLEROFWORLDS]

This episode is SO awesome. KEEP IT UP!

[@Halosty45]

I wanna play spore now.

[@linko9670]

God, my science class is apparently very misinformed.

[@PotatoMan007]

Wow, learned a lot! Thanks Hank 💗

[@johnnyratna9008]

You guys over at SciShow are AWESOME.

[@TheBhuvan002]

Someone make 2:21 into a gif

[@elizabethj1167]

TheBhuvan002 On it.

[@MisaelKpo]

s30.postimg.org/m8cksnf4v/False.gif

[@fossilfighters101]

MisaelKpo ReRocho It's beautiful. :)

[@InterestingTed]

MisaelKpo ReRocho Nicely done!

[@e60stevan]

TheBhuvan002 gif is dead

[@oxycominum]

Until I missread the title I was never aware of how close "Nicest" and "Incest" are. Scary.

[@nickoemord]

You do the best SciShow,... Shows. Keep it ^

[@perseuxx]

Amazing job with all this channels, congratulation

[@AngelofEresos]

I actually planned on making a game where you can fight natural disasters with a legendary katana containing the soul of an angel. There was a demon living in a black hole stirring up this trouble, but now i'm going to have him eventually upgrade it to a Quasar. That's gonna have a shitton of HP.

[@CLOYSTEROYSTER]

You should reference the meme 'Shoop dah Woop' for the demon; it doesn't have to be his name but if he is a quasar, i would be a humorous reference. :3

[@AngelofEresos]

He's an actual, though little known demon, named Malphas. Fucking with nature is kinda his shtick.

[@PinkFK2R]

Minute 3:52... My mind is blown...

[@NaZaRK3]

why?

[@PinkFK2R]

Because I love to listen when people talk about the galaxy :) It inspires me.

[@NaZaRK3]

OzzyAlexMason oookay, but why 3:52??

[@1waychild]

Most excellent video!!!

[@Rob-lw8to]

I bet Sebastian the crab is sat up there laughing at us .

[@20003771]

This should've been on the space channel....

[@cynarka850]

These episodes need to be wayyyy longer

[@lykensenbri9594]

I love how he describes Michigan. I live in Michigan and I looked outside and it's snowing like crazy

[@IoCalisto_]

People, and cheetahs, and sunflowers... U HIGH M8?

[@IoCalisto_]

wow he said it again...

[@araknidude]

"Like, a THOUSAND TIMES more energy than ALL THE STARS IN THE GALAXY... COMBINED!!"

[@Acquavallo]

This video was so great!

[@g00dvibes47]

Hank had the best educational personality on KZbin

[@Snailman3516]

I vote that we call Kepler 62e Kamino. I believe I speak for all of the star wars fans out there.

[@ShotgunLlama]

Could a tidally locked planet have a small habitable zone between the hot and cold sides?

[@ethansheehan1002]

Yes, in fact scientists have discovered a planet like that which could hold life

[@Axioanarchist]

In fact, it's Proxima-b - a tidal-locked planet orbiting close to the red dwarf Proxima Centauri mentioned in this very video.

[@miclarkson6825]

It is extremely close to us, as well. :)

[@blackoak4978]

It would depend on how u define habitable. Sure microbes could live there, but that isn't very useful to us. Odds are that any such area on such a planet would be a never-ending mega storm as they mentioned, as the cold atmosphere at the edge of the dark side met the superheated atmosphere of the hot side. It would be fanatic to study from orbit, but I wouldn't actually want to go there. Also, one variable that has a large effect on the "habitable zone" of a planet is how hot the planet is when it forms. A hotter planet can be habitable farther out while uninhabitable when closer in. A cooler planet with otherwise similar make up would be uninhabitable further out, but habitable closer in

[@heatherswanson1664]

arxiv.org/pdf/1405.1025.pdf "Life, if it manages to struggle along on such a planet, will be very hard or perhaps be underground. More likely a circular belt between the two sides - a sort of “twilight zone” - could be the place for life to evolve and flourish. In this dusk band around the planet, where star will be permanently hanging very low near the horizon or perhaps the stellar disc partially peeking above the horizon, with an ever-colourful red, yellow sky due to scattered light, the temperatures would be more moderate, right in between the hot and cold sides. However the heat on one side would cause the air to rise, creating a low pressure system, while the cold on the other side would cause the air to sink, creating a high pressure system. This would cause the planet to experience a constant and violent circulation of air, or, essentially a planet-wide hurricane. The constant air circulation would actually circulate the temperatures extensively and extremes in temperature would mitigate. Water cycles with huge rivers crossing from cold to hot side might make living there possible. "

[@ofek141]

I've been searching for a while a video which tries to explain the debate over the definition of a star,dwarf star,a moon and so on... if you'de so kind to even explain a very intriging concept of a black+white dwarf. except that - love your show so much, watchin' it daily and inspire me on so many levels.

[@AnanyGupta]

good to know... thanks for the video

[@IoCalisto_]

"Nice safe, supermasive blackhole". ALRIGHT

[@Dracorex13]

>Expected video on the likelihood of planets being inhabitable (preferably with a mention of Drake's Equation) >Received video on the likelihood of PLANETS FORMING AT ALL PERIOD

[@dammitdanFTW]

What's your point? Did hank forget to rendezvous with you prior to filming again? There is nothing worse than when we have to watch another scishow without dracorex13's approval.

[@Dracorex13]

ebkdan I mean no disrespect. The all caps is to be imagined being spoken with the awe of someone who has had his mind blown, because that's what this video did. I had no clue that planetary formation was such a sensitive process.

[@dammitdanFTW]

Dracorex13 my apologies. I misinterpreted your comment. Go science!

[@ElCLASICO1137]

one of my favorite episodes of scishow is this one!

[@outlouis2054]

Excellent video

[@MGShadow1989]

One term missed here is the Goldilocks Zone, a specific distance from a specific type of star that in theory allows a planet to be just the right conditions for life to form. The description of, not to warm, not too cold, not too big, not too small - most people get the referance; main point, it's an extremely specific set of conditions that even our own planet isn't quite settled. The life of the earth has gone though a ridiculous number of changes, volcanos causing earth to actually become inhabitable for a while with the mixture of acid rain and sulphurous clouds both blocking out the sun and reducing the oxygen level to practically nothing - this was repeated almost exactly with the meteor that killed the dinosaurs; essentially a galactic reset button. Next we have the ice age, not inhabitable, but in terms of how much it changed the earth it ranks pretty high. What I am getting at is this. A planet we look at now that could potentially support life but doesn't, either has, or it might at some point; and it could be the most seemingly insignificant change that could cause life to form. Knowing how much luck was involved in the evolution of life on earth is the main reason I get so annoyed by any form of conflict, be it a war or just an arguement over something like sport for example.

[@MGShadow1989]

Read the wording again... lol Inhabitable means it doesn't support life, I said it's not inhabitable - sort of a double negative. The ice age was a habitable climate, but it was harsh; on the land as well which was my main point.

[@sectorcodec]

I was taught the sun was an average star :(

[@MKHsma]

The Sun is of an average size :) .. Not too big, or too small. However there are A LOT more small (red dwarf) stars than there are averaged sized or giant stars out there in the known universe :)

[@xxhellspawnedxx]

It is, size-wise. I mean, on the spectrum of the smallest star to the biggest star, our sun ends up somewhere towards the middle. But it's not average if you take into account how many stars are smaller and larger than ours, as Hank stated.

[@samuelgarcia8396]

Youre pretty.

[@lonestarr1490]

Welcome to the difference of average vs. mean ;)

[@veganchaatparty]

Super Superb!! Super Superb!! Super Superb!! Super Thanks for Sharing!!

[@nilslevsen5522]

Great episode

[@SneakyNinja122]

Space excitment is TERRIBLE needs to be on a t shirt

[@asterixgallier8102]

With some deadly x-ray burst burning the letters down.

[@chengwong3307]

Earth is so perfect compared to the rest of the universe. But we are still destroying ourselves and this planet...

[@godofwinetits3826]

Cheng Wong , you would say earth is perfect because thats the planet you were born, but if you look at people living and dying in harsh environments you wouldn't say that

[@chengwong3307]

aris oreta Have you watched the video? I'm referring to that.

[@jhosioja]

Cheng Wong We may be destroying ourselves, but we can't do shit to the planet. Even if we manage to wipe out 95% of the species along with ourselves, it'll be like the 5th time that's happened in the last billion years. It'll recover. We'll just be gone.

[@CreationTribe]

Cheng Wong you mean perfect for us. I'd say the universe is pretty perfect everywhere, and that includes not being perfect for us in a vast many places. heh - I'm just being a jack-hole :P

[@thedeutschblitz6900]

+jhosioja I love people like you that say "HA no were not" to those kinds of people it makes me laugh

[@justinwarthen]

Great show

[@GabriellaBlack]

Thanks, Mr. SciShow. I learned something new.

[@pandorasflame7742]

I'm somewhat disappointed that the other candidates weren't mentioned.