Could Aliens Build A Rocket To Escape A Super Earth?

Sure they could, but it would require vastly more work.
A Super Earth is a class of small terrestrial exoplanet which is 25%-100% larger in diameter than Earth. Many of these have been discovered and some are in the habitable zone of their parent starts. Which lead people to ask whether a civilization developing on these worlds might be trapped and unable to develop a space program
Using Universe Sandbox I show a few example Super Earths and then, in Kerbal Space Program we fly a massive rocket that can just escape.

[@imperialofficer6185]

Aliens from a low-mass world on their wooden rocket: "In the name of the Crown! Submit yer spices and dyes!"

[@sumreensultana1860]

Bruh

[@sumreensultana1860]

HUMAN:- AHHH WHAT THIS I LANDED ON Aliens :- noo you landed on wooden rockets i was gonna land it later Humans:- bruh bring those nukes now

[@jackeyboy6538]

Outer wilds type beat

[@theCodyReeder]

Another problem for re-entry is the atmosphere is going to be held tighter to the ground so the air density will rise very rapidly and I imagine it will be like hitting a wall.

[@scottmanley]

Yeah, scale height is going to be flatter, but I'm sure existing capsule aerodynamics would be enough to control descent using lift from heat shield.

[@tolga1cool]

Cody'sLab Wouldn't that be assuming they have the same amount of atmosphere as the earth. If such a huge planet had quite a large atmosphere it could still be quite high

[@HuntingTarg]

Glide path re-entry from deorbit burn. A hypersonic airframe should be able to handle it.

[@iamsick5204]

So if there was a mountain like Everest the top would pretty much be in space... So would it be easier to build a rail gun to get to space?

[@epicbastard1]

Super earths don't have big mountains, gravity keeps them relatively flat.

[@horstherbert35]

>"it looks for stars passing in front of the sun" well good luck with that

[@NineEyeRon]

Jim Panse pls don’t put stars in front of the sun

[@geemanbmw]

@@NineEyeRon lol

[@AgentTasmania]

It would be a very important discovery, though we'd probably see it before then

[@TheMoonRover]

@@No_Control Even so, he still misspoke. It looks for _planets_ passing in front of stars.

[@ironcito1101]

@@No_Control I'm sorry for the aliens, but _the_ sun is _our_ sun.

[@innsj6369]

*I can imagine what kind of things would seem incredibly difficult to those aliens, but easy to us.* "Not long ago we managed to start construction on our first space station. After 35 launches, it is 10x5x15 meters. We're pretty proud of it since it cost a lot of money." "Also, we are just starting to begin work on interplanetary probes. So far, none of our rockets can reach escape velocity, but we're working on it." "Our smallest orbital rocket is about 150 meters tall..." *Meanwhile, there's another alien species that lives on a low-g, low atmos pressure world.* "Oh yes, by the way we are having some trouble with our space program, the amount of rockets we are launching is slowly pushing our planet around." "Multistage rockets? Doesn't that just complicate things?" "Parachutes? Oh we tried those, they only work at high velocities. It's better to just slow down with the engines."

[@LloydieP]

Alexandre Fyne Cheers!

[@ancaplanaoriginal5303]

well, you still need a multi-stage rocket unless you want to fly around in space with a giant stick that consumes fuel and creates a shitton of inertia

[@applesaregoodeatings]

The parachute thing made me laugh

[@ThePrimalEarth]

that last point was just Elon musk talking

[@N3bu14Gr4y]

Elon Musk confirmed alien.

[@eegma5596]

*Humans* "Yeah, those aliens living on super-earths are trapped..." *Aliens from a low-mass world* "Yeah, those aliens living on 12,000 km wide planets are trapped..." *Aliens from a super-earth* "Just another comms satellite launching on a 5 000 ton rocket. Nothing special."

[@deathpick2]

though to be fair on a super earth they would have more land area to mine though how well they could get the fuel and metal would depend on how resource rich their planet is

[@sosig6445]

@@deathpick2 On avarage they'll easily have more manpower and resources

[@matchesburn]

*Aliens from a super-earth looking at a Saturn V* "Is this your guys' first sub-orbital rocket design?"

[@N3bu14Gr4y]

Actually, aliens on a Mars-sized planet would still say that our planet would have a radius of 24000 kilometers. Why? Because a meter is 1/10000000th the arc length from the north pole to the equator of the planet where it was defined. Half the radius means half the circumference, so a meter defined on such a world would be half as long as an Earth meter.

[@mattshap9731]

TinyFoxTom Did you just pull shit from your ass and hope we were all flies? The meter is defined by a literal universal constant as the exact distance traveled by light in a vacuum in 1 / 299,792,458th of a second.

[@jameshansen1903]

Ah, the majestic subcontinent of Florida.

[@freeman2399]

Satans dick?

[@drabberfrog]

I live in Florida

[@IexoPeoa]

@@drabberfrog Me too, I feel your pain.

[@n00b_n00b_]

@@IexoPeoa why?

[@thefederalrepublicoferusea3900]

@@n00b_n00b_ Florida is perpetually boiling

[@GareebScientist]

*There will be some civilization out there which is half the size of earth wondering if it's possible to launch a rocket from a planet twice its size*

[@GareebScientist]

Light hearted. Not to be taken seriously

[@gajbooks]

Inb4 we discover Outer Wilds World.

[@DumbSloth87]

You mean Kerbin? Yeah, we know about them.

[@GareebScientist]

DumbSloth87 I can neither confirm nor deny the same

[@GareebScientist]

gajbooks yes

[@epicbastard1]

They will not bother with space, until they realise they can nuke their enemies from the other side of the planet.

[@dynamicworlds1]

Stoyan Todorov to be fair, that sounds a lot like us...Sputnik was built using the casing of a nuclear warhead to make a statement.

[@Not.Your.Business]

DynamicWorlds, you missed the joke, didn't ya?

[@migkillerphantom]

If every ICBM needs to be the size of a manned launch vehicle, they'll probably just stick to bombers and very fast cruise missiles.

[@wojtek4p4]

migkillerphantom It's good to have options. You can just use smaller nukes. Or just have a few of them in orbit. If launch vehicles have to be so big, you're better off creating a stockpile of nukes long before any potential attack.

[@KuraIthys]

Surely with atmospheres likely to be thicker, you'd gain relatively more from aerodynamic forces than you would on Earth. You'd likely design winged missiles if that were the case. (and perhaps use high altitude balloons in preference to satellites. I guess it really rather depends...

[@coryman125]

So aliens from a larger planet would be stronger (to cope with higher gravity), but have less space travel capability, and aliens from a smaller planet would be weaker but have easy access to space? Sounds like the basis for a sci-fi novel

[@SemNome-ds1qy]

coryman125 Unless they discover anti gravitation.

[@BaconHer0]

Stronger is relative. They might be slow hulking short creatures that are composed mainly of thick bones. They may also speak really slowly with little expression

[@_zurr]

Bacon With Excitement: It is nice to see the Elcor species being described so well by humans.

[@miskakopperoinen8408]

The aliens from a larger planet would also be stocky and relatively small, while creatures originating from low gravity would have less problems growing long limbs and large bodies. Think of minuscule bears, rhinos and armadillos for a giant planet and monstrously huge, thin-limbed and slender creatures (praying mantis, giraffe, harvestman spider) for lighter planets

[@coryman125]

Hm... Larger planet definitely sounds like the place for me then :P

[@speedy01247]

when he mentions the time editing and you realize that the rocket launch actually took 44 minutes to reach space.

[@acbthr3840]

By my reckoning, a first stage that uses air breathing jet engines, fixed wings, and takes off from a runway or big ramp would make much more sense on a planet like this. With the huge atmospheric pressure you can get more air moving through the engine to help with combustion and you also get WAY more lift from the wings. Even with the higher drag, it would probably be much more efficient

[@aauwhatitdo1582]

Yes.

[@katfox2004]

that would work on earth, by using the engines devoleped from project pluto to get so fast and high without using any fuel that its like launching a normal rocket up at the karman line

[@coolspruta]

The problem is, that a Super-Earth would have a less visible curvature and thus, a Super-Flat-Earth community, that would just ruin everything.

[@eekee6034]

The Flat Earth Society, moon landing deniers, and others have only really gained a (semi-)serious following as people lose confidence in authorities, including the "knowledge authority" of science.

[@aauwhatitdo1582]

lol.

[@thomasslone1964]

Yea, until the real scientists get involved and they stop killing them for saying stuff they don't like

[@forwhomthetacobelltolls9789]

Also the slimes

[@HarryS77]

It's okay, you can just fly up in a spaceship and oh I see the problem.

[@markmaurer6370]

Wouldn't you imagine that such a civilization would use airplanes of some sort as their first stage?

[@Ibyys]

I'd like to hear more about re-entry, and the scaling of its properties and effects in relation to the different variables of planets like super-earths. It's pretty apparent that the bigger the planet, the harder the re-entry, but you never fail to illuminate me to things I don't even know I don't know about things I frankly barely know anything about.

[@consultkeithyoung8982]

You can look at Allen Eggers (hope I'm spelling that right). It's what we used in Aerospace Engineering classes to calculate re entry.

[@CarFreeSegnitz]

I smell a business opportunity. Humanity should roam around the galaxy looking for aliens stuck on their super-Earths and sell them the technology to get them into space. Space elevators, rotating tethers, orbital rings... whatever. All technologies that they wouldn't be able to implement on their own.

[@NyoshaM]

if you have the ability to get there and there is the profit to take something from them, why don't just threaten to destroy surface from space?

[@digitalnomad9985]

"why don't just threaten to destroy surface from space?" Because to get something from them (other than information) you have to give them exit tech. If you piss them off, they can climb the exit tech and hurt you. There are likely to be more of them on the larger planet than there are currently on Earth, particularly more than you brought with you. Despotism is inefficient.

[@jesseward4115]

Because we shouldn't be evil SOBs.

[@michaelg4931]

+Jesse Ward >>> Ie, don't be Google ;-)

[@nekroneko]

We have concepts to share with you. Fancy some Third Wave Feminism?

[@mrJety89]

Whichever metric we take, earth is very lucky.

[@HuntingTarg]

Well, he could mean "Earth is very lucky to have us humans!" kzbin.info/www/bejne/pYSxf5SsZ8qMrc0

[@cmuller1441]

Festivejelly yes and no. People win the lottery every week. That doesn't mean the lucky ones are not lucky. And maybe we are not that lucky. A lot of people around the word are very poor and die of starvation and deseases that are curable (with enough money). The biggest killer on earth is... the mosquito...

[@mikicerise6250]

Earth gets periodically smashed by asteroids and other extinction causing events, and orbits a star destined to roast it in a billion years or so. I'm sure there are luckier planets. Imagine being native to Titan. Now that would be lucky.

[@PrivateSchemers1]

From a human-centric perspective, obviously it would be perfect.

[@jasonsinclair6949]

HE IS GOD THE CREATOR

[@dionemoolman]

I’ve been thinking of a science fiction story that revolves around this. It takes place on a super earth and it’s habitable moon. On both worlds there are humanoid species (thanks to panspermia and ancient civilisations) with rising civilisations. The super earth has gravity almost twice that of Earth, meaning they’re trapped there, while the moon has less than half Earth gravity so it’s super easy to get around. As a consequence, the civilisation on the planet is trapped and stagnant despite being much older.

[@veramae4098]

There's an old novel about a heavy planet, humans explore both from orbit and brief sorties to the surface. (Edit: googled and found it. "Mission of Gravity" by Hal Clement) Cool thing, intelligent centipede like creatures that live almost as if in Abbott's Flatland. I am so sorry I cannot remember the name of the novel. The centipede species is terrified of heights and hug the ground. Humans get stuck. Part they need accidentally came down far from the base. Make a deal with a centipede whose rather like Marco Polo or Henry the Navigator. Get a centi crew together and go get this part. In return we'll give you knowledge. Centi agrees and there's an amazing voyage into which the physics have all been worked out. (Only not possible is the size of the centi and the brain it would have to support to be intelligent. I know there's a biological law describing that relationship, can't remember that either!) At one point a human picks him up and moves him over an obstacle, then puts him down. Existential crisis, monstrous fear, you name it, and maybe he goes slightly nuts but now he's open to possibilities he never would have thought possible, or even moral, before.

[@milky_wayan]

super-Earth aliens might talk about going to low orbit like we talk about going to another star :o.

[@ulysisxtr]

RIP Jeb and Bob...

[@jesseward4115]

HIS NAME IS BILL! GET IT RIGHT! HE IS A GODDAMN HERO! YOU NEED TO SHOW SOME RESPECT!

[@-Rook-]

'F'

[@doodlebiscuits1750]

F

[@jonathannguyen561]

No your not, wait are you?

[@737smartin]

I can't believe @Scott Manley tricked me into watching what turned out to be a snuff film.

[@zapfanzapfan]

They might have to skip chemical rockets and go straight for the nuclear stuff to get off the ground. Project Orion instead of Apollo :-)

[@zapfanzapfan]

Project Orion, not NERVA. Orion was launching using nuclear bombs, it has enough thrust :-)

[@TheOneWhoMightBe]

A Space Fountain is another option. Then from the fountain you can build a ring and then you're really in business.

[@jarredallen3228]

Nuclear stuff actually gives you worse TWR than chemical (see en.wikipedia.org/wiki/Spacecraft_propulsion#Power_to_thrust_ratio). A rocket to take off from a super-Earth would have to have Solid-Fuel motors on the first stage to actually lift off the ground, and then nuclear stuff to do your circularization after the solid-fueled engines lift you up into the air. It's also much more reasonable to use NTRs (such as the NERVA) than Project Orion-type rockets. As fun as it is to use nuclear weapons for space exploration, they could cause a lot of harm if done in low orbit (imagine Starfish Prime happening everywhere, all of the time). With NTRs, you don't have to worry about that.

[@djinn666]

"If gravity is 2 g and T/M-ratio of 1,2 is enough, that means half of the blast-off mass will be engine." That's not what thrust-to-mass ratio means. The "mass" refers to ship mass, not reaction mass. To figure the amount of reaction mass you need to get to orbit, you have to look at Isp, which for the Orion can be measured in hours or days instead of seconds, which is the case for chemical rockets. The numbers you're quoting is probably for a ship designed to leave from Earth. That means the design calls for the smallest nuclear explosives that would work (0.03 kt). It's actually hard to make them that small, which why there's a lower limit for the size of Orion ships, but no practical upper limit. A design for a super earth would just use slightly increased the yields.

[@stefanr8232]

They just need to build one huge Orion rocket. Put all satellites, space stations, habitats and space manufacturing plants in one vehicle. The small Orion designs fit with the types of exploratory missions we do now or did in the 20th century. The designs for interstellar generation ships were much larger. There is plenty of thrust if you use full size bombs. You can also pack the bombs with reaction mass.

[@demiRaziel]

And that is why we need to find the gravity hack console command for the universe.

[@bobbobinson7788]

Really? You don't know a command that basic? It's obviously Ctrl+Alt+F13.

[@OverlordZephyros]

We need to find eezo to create a ... "Mass effect" (wink)

[@isaiahphillip4112]

MUUURPH

[@Yorickje1234]

No, that would be really destructive and complex. HyperEdit alone suffices.

[@passthebutterrobot2600]

basogoreng : I'm not sure it's possible to hack a universe from the inside, unless the engineers/Gods that built it deliberately made it possible.

[@chuckymcnubbin1518]

Well, if an alien civilisation did evolve on a plant that size where their scientists managed to get into orbit, you can pretty much guarantee, they'd have to deal with their version of flat earthers. 😂 😂 😂 😂.

[@brunos6599]

Flat-earth movement is a Muslim movement and you're a islamophobe for making fun of them.

[@Bob-jh6vk]

@@brunos6599 who asked

[@keeganharris186]

Mestre Shake what the hell are you talking about. The Muslims have nothing to do with it.

[@user-wq7qg9mh6r]

Mestre Shake amazing, everything you just said is wrong

[@sigmamale4147]

@Anant Tiwari he's trolling

[@OverlordZephyros]

The more hard a thing is... The better the tech they will create to overcome it. Necessity is the mother of all invention

[@v44n7]

Probably If they ever look at our rocket technology they would be laughting. Imagine a orion drive or amazing nuclear engine technolgy. They would see how we get to space & laugh! ha ha

[@knownas2017]

@@v44n7 Our Vacuum engines would destroy theirs, though. As it takes them longer to get to space the less research they would do for space engines. We'd have more time researching the topic than them, as we'd already be in space.

[@hajostork9351]

so, they'd go straight for nuclear lightbulbs, as chemical engines are just insufficient?

[@lowestpoint1047]

@@knownas2017 but they could optimize payloads, and invent some interesting efficient engines for that.

[@mikicerise6250]

Now imagine that your civilization lives inside a Super Europa. Good luck. ;)

[@Hogaboga101]

Difficulty: Nightmare

[@rohanpotdar908]

*launches chemical rocket* *blows up planet*

[@gonun69]

Now I wonder if there is a civilization out there on a planet with half the earths gravity thinking about how ridiculous it would be to launch rockets from a earth-sized planet.

[@nickchan6498]

Gonun since they use Ssto rockets

[@stephencourton3328]

Well except unlikely a planet half size of Earth in habitable zone retains enough atmosphere to develop intelligence.

[@floo1465]

Stephen Courton Titan has a very thick atmosphere, and it’s barely bigger than the Moon, and Mars used to have an Earth-like atmosphere until it lost it’s magnetic field.

[@JohnSmall314]

@@floo1465 Yes but Titan isn't in the habitable zone. It's kept its atmosphere because it's so far from the Sun.

[@rossdtool]

I was about to say "Beings from a planet half the size of Earth are......" until I read some comments and realised that is what everyone else said.

[@user-mr1um1cg5v]

Super-Earth or “I can’t-even-lift-my-foot-crappy-Earth” ? )))

[@grossersalat578]

Besides from the interesting content, the voice of Scott Manley with the music of Universe Sandbox is soooo chilling.

[@The_ANNOholic]

My favourite Earth is that one you see from the ISS

[@Axodus]

>Implying more than one Earth

[@JasonHenderson]

I read that as "my favorite view of our earth is from ISS"

[@Axodus]

"My favorite Earth" Implies there is more than one Earth, I just thought it was kinda funny.

[@theyellowdart6039]

Pixelgaming and Stuff since they decided to label these planets "super-Earths" there kind of are more than one earth.

[@Axodus]

+The Yellow Dart No, That doesn't make sense.

[@AlexanderGoncharenko]

*explosion* - I'm Scott Manley, fly safe!

[@tfsheahan2265]

Ironically, your admonition to "fly safe" comes seconds after the kerbal craft is shown blowing up on reentry. Looks like you could stand to follow your own instructions.

[@gnuthomson]

Great video as usual, Scott! One correction though. At 1:43 you said "stars passing in front of the sun". If that even happened to our sun, we'd be in deep trouble. Planet passing in front of a star sounds better and much less scary.

[@SeeThroughist]

LOL... it also irritates me when people talk about other Solar Systems... Sol is uniquely the name of our star... other stars have their own names... for example Sirius has a Sirius System it's not a Solar System... it's the Sirius System.

[@williamblack4006]

@@SeeThroughist Indeed, "Planetary System" is the correct term. Definition: A planetary system is a set of gravitationally bound non-stellar objects in orbit around a star or star system (star system, i.e. more than one star). Generally speaking, systems with one or more planets constitute a planetary system, although such systems may also consist of bodies such as dwarf planets, asteroids, natural satellites, meteoroids, comets, planetesimals and circumstellar disks. The Sun together with the planetary system revolving around it, including Earth, forms the Solar System.

[@sylvain7277]

Every time I imagine I'm the only one wondering something weird, there's a video about it and it's usually Scott who made it.

[@BrowenWhitefire]

What about balloon assisted launch? Would the higher gravity affect the density of the atmosphere at lower altitudes? Making it easier to get lift out of balloons? *fixed*

[@thermophile2106]

Maybe. There would probably be more total atmosphere, and it would have a sharper density gradient. But you would still have to reach orbital velocity, and keep from falling while accelerating horizontally. I was thinking a plane based launch might be better, because you can get some of the horizontal velocity. Especially if you have fancy futuristic SCRAM and RAM jets.

[@lurandir8230]

If you want to pull 10KM up 3 MTon Rocket, you need to create a baloon which is able to take volume of the 3 MTon of the air + its own weight at 10 KM up, where atmosphere is about 10 times less dense (in case of the earth amount and composition). This huge balloon would need to be stable enough and resilient enough for a safe super heavy rocket start... I think mountain top start is better in almost all parameters balloon start would have ;P (except balloon's ability to start from anywhere on the planet)

[@sleepib]

Not really, the hard part is the velocity, not the altitude.

[@bobbobinson7788]

How about launching a super-rocket, in a Massive RAM jet plane, off a giant platform being lifted by a Giga-balloon.

[@lurandir8230]

@sleepib sure, but to get high velocity you have to either carry a lot of fuel or accelerate in as close as possible to vacuum atmosphere, which you can get on high altitudes. I agree its pointless on earth as relatively "small" rockets can produce enough power to counter gravity for long enough to reach into high atmosphere. But the cost to reach there multiplies many times on super earth.

[@Cragrim]

Love this video, I've pondered about this before as well. Thank you for making it Scott!

[@5chr4pn3ll]

Senseless kerbal murder!

[@Narglepuff]

They died for science

[@tezer2d]

Im sure Scott is one of those human supremacists

[@mal2ksc]

Many kerbals died to bring you this message.

[@RichardAllen7753]

Oh the Kerbality!!

[@STKS1991]

Would aliens from a super earth even have a desire to leave? Twice as much atmosphere to look through when observing other planets/stars, maybe they don't even have a moon to be a carrot on a stick in the public's imagination. how might a species built for life at 2g survive in space or on return, bone density loss or cardiovascular muscle wasting could be fatal, a heart built to work at 2g might go overboard in micro gravity.

[@Patchuchan]

I think aliens on a super Earth would be more likely to try and use nuclear propulsion in their upper stages or even try something like project Orion.

[@WesleyG8857]

I love Scott Manley! Idk why it just dawned on me to sbscribe today when I have been watching you for 2 years... Better late than never, right? Keep it up!

[@Bibibosh]

Scott Manly - I want to say, i enjoy watching your videos! Your videos are brilliant!

[@patrickalm9705]

in this simulation does it take into account the fact that with a higher G environment structural design needs to compensate and therefore base mass on structure

[@alanowa123]

*just burned Bob and Jeb in super earth's atmosphere* Scott: fly safe! 😂😂😂

[@k3v1n73]

1:43 "star passing infront of the sun" yeah i guess we would be able to detect that. if we survive

[@andreass2301]

This was great, and on a topic I wish would get discussed more often whenever a new 'new Earth candidate' planet is found. Thanks for making the video, 9/10 (point lost for Kerbal butchery).

[@Sarge714]

Scott, on a Super Earth whose atmosphere is 14.7psi at the surface, wouldn't the Kármán line be lower since more mass would compress the atmosphere more? So instead of having to rise to 62 miles to reach space, you would only need to rise to lower height to reach space? So would you really need more fuel to reach space? This is a very interesting thought experiment, thank you. :-)

[@aspirerl4807]

You'd still need more deltav to reach orbit because of the size and gravity, atmosphere doesn't account for too much deltav losses, but yes it would save some deltav getting out

[@DenverStarkey]

escape velocity is not so much about leaving the planet in question's atmosphere , it's more about escaping the planet's gravitational pull. If earth had a tighter atmosphere that clung to the planet closer you'd stil have to reach a certain point away from the planet to not just be pulled back into it.

[@trygveplaustrum4634]

My gosh, I love exoplanets. Time to go play Project Discovery again...

[@cdrbmw]

You are awesome. Never stop posting videos

[@EnigmaverseElysium]

I always find myself liking your videos before I watch them, Mr Manley.

[@Biped]

12:18 i think you didn't mean fuel but velocity there. If it only where twice as much fuel the rocket equation wouldn't be that scary...

[@eugenesesmaiii3278]

Another interesting factor to consider would be the physical size of the alien population themselves. Double the gravity means they had to evolve a physical structure that allows them to move comfortably around their environment.

[@davidberry7115]

The linear scaling of surface gravity and radius just blew my mind. It seems so obvious looking at both the equations now but i would of never of drawn that connection.

[@SynSauce]

Lol the intro music threw me for a loop. I was like "this isn't Scott?!"

[@toastycrab5175]

"It looks for stars passing in front of the sun" what?

[@zelda_smile]

the sun is really far away

[@Axodus]

Uhhhhhh, The other sun.

[@scottofengland]

LOL yes i thought the same

[@HurricaneSA]

Maybe he just misspoke and meant to say "It looks for planets passing in front of the sun". Which would make a lot more sense. ;)

[@VinayPai]

I assume his misspoke, and meant to say planets passing in front of the star (i.e. their sun).

[@jimstafford9409]

Interesting video. I question one statement. however, There is no direct relationship of mass and radius. The mass depends on the nature (i.e. the density) of the elements constituting the planet (as well as the radius). I think what you meant was that surface gravity (but not escape velocity) varies inversely with the square of the radius. Accordingly, it is possible in theory to have a planet that has twice the mass of Earth (and therefore a much greater escape velocity) but whose surface gravity is equal to or less than that of Earth if it is metal deficient compared to Earth but has a larger radius to accommodate the overall greater mass. A planet with twice the mass of Earth and 1.415 the radius of Earth would have a surface gravity of approximately 1g despite a much higher escape velocity. Comments?

[@josephschaefer9163]

Because the radius is bigger, with the same surface gravity, the escape velocity is about 1/3 more

[@hajostork9351]

his assumption is that we talk about rocky planets, that is, the density of the rock being the same as here.

[@eekee6034]

My first thought is, "'Metal deficient' doesn't give me hopes for their space program." ;)

[@ThomasGrillo]

Oh, you cruel Manley, you! Not giving the poor super earthers a proper heat shield. LOL. Very interesting concept. Thanks for sharing this.

[@Cocoshunt]

Manley, yer a legend mate. Happy New Year

[@topsecret1837]

There’s an entirely different issue here in that with twice the gravity everything built INCLUDING the rocket would have to take the additional stresses and would weight even heavier than on earth just to stand upright.

[@habddz]

but they may have better materials or stuffs outside the periodic table For example, a not rare earth that is light and strong, and then they made alloys out of that thats not only 100 times stronger than steel, its 1000x lighter and has a melting point of 20 million celcius. We know soooo little about material science

[@Lucius_Chiaraviglio]

@@habddz No way. If the laws of physics are the same there, they will have the same elements available (although not necessarily in the same proportions).

[@eekee6034]

@@Lucius_Chiaraviglio The point is "we know so little about material science." The same is true of mathematics where top mathematicians will tell you that our knowledge is like small islands in a vast ocean of ignorance. Connecting the different "islands" of mathematics is a major goal. The result of all this is it would be surprising if an unrelated civilization produced exactly the same technologies we have.

[@Lucius_Chiaraviglio]

@@eekee6034 Even so, you can't get a much stronger (if at all stronger) chemical bond than what we have already found. So they might be able to make a slightly stronger material than carbon fiber for the same density, but not much stronger.

[@outspan87]

What about a spaceplane type of aircraft using as much lift as possible to get to orbit?

[@David-zy1lr]

Maybe with an airbreathing ion engine! Edit: okay that would probably generate too much heat going 16 km/s

[@jerryricks8389]

That was a really fun discussion of several interesting topics!

[@jerrysedlacek6354]

a very intriguing idea on why we may not see as many aliens as one might expect, clever

[@TheExoplanetsChannel]

I bet some alien civilization has already done it, perhaps in another galaxy..

[@5995Oblivion]

Perhaps a long time ago.

[@jblakeplays2541]

Perhaps far, far away

[@SemNome-ds1qy]

Phearps in our Galaxy.

[@michaelt3172]

The Exoplanets Channel or in this galaxy

[@lurandir8230]

if they did, most likely in another galaxy, as alien civilizations building rockets on super earth are by definition subset of the alien civilizations, and that would statistically mean that our galaxy is fairly rich in space fearing civilizations which we did not observe up until now

[@3800TURBO]

I can imagine our planet as a tiny dot in some aliens telescope and them saying, do you think anything would live there?

[@starlight8260]

Scott, you are by far my favorite rocketman. Hat's off sir!

[@oberonpanopticon]

Nuclear pulse assisted launch: “At last! A worthy opponent! Our battle will be legendary!”

[@qqq1701]

A civilization on a planet like this might have come up with some kind of "exotic" propulsion system out of necessity that seems totally normal to them. They would look at our rockets and be amazed how advanced they are while our jaws drop at their gravity repulser field generators and what not.

[@Anvilshock]

Well, in a sense, we do have the necessity for "some kind of exotic propulsion system", too, and we have less gravity to develop it under, but do we have it yet? I don't see anything flying into orbit and deeper space that's not propelled by rocket motors.

[@mapesdhs597]

Indeed, there's a bit of wishful thinking here that since such a super-Earth species would "need" something better then somehow they would discover it (well, what exactly? They'd have the same materials as we do, and it's not as if we don't simulate higher pressure conditions all the time in materials science research), but there's no basis for such an assumption. The deeper irony is that most of our advanced propulsion technologies have been developed because of war, so perhaps these super-Earthers might have a better chance of breaking free of their planet if they're more like Klingons, forced to develop ever better tech much faster than we have. :)

[@maxime3648]

nuclear pulsed propulsion maybe, though they would need a lot of deserts to do that

[@Ezullof]

@mapesdhs We have no proof that technological progress is linear, because we only have one example - us. Maybe it is, and every civ in the universe is developping like we do. Maybe it's partly the case and all civs are roughly similar, with some differences based on environmental pressure (like how biological evolution works). And maybe wars aren't the only pressure that can make a civilization develop its rocket science. Maybe there are religious reasons, purely commercial ones, or even just for the sake of science. Maybe it's completely not linear, and there are civilizations that know space travel but not nuclear weapons. This is a completely speculative field, and there are as many possibilities as there are logical ideas about it. In the end it's quite similar to speculative history - could the state of humanity have been different? Or did we need to go roughly were we are now? What motivates technological progress?

[@TheVergile]

possibly, but that is science fiction talk. It is unlikely that technology as a whole would develop much differently. Id assume 80-90% of technology will be shared by most sentient species of the same development stage. Most sophisticated machinery requires a broad knowledge of a very wide field of science. It is extremely unlikely that any society able to tamper with gravity would not have a very firm understanding of chemical rocket propulsion. Science fiction likes to produce different alien civilisations with extremely different technologies or each with a very special exotic tech. But this just isnt the way technology works. Special fields always develop as extensions of a very broad base of scientific research. Science is interconnected.

[@zegreatpumpkinani9161]

My Dad was explaining to me a sci-fi book he had heard about involving the Fermi Paradox. Basically it explained that any civilization willing to broadcast their existence to the universe had been eradicated by other civilizations.

[@blintorzabat5798]

Flying to Valhalla. The Killing Star. The Dark Forest. Scary idea, hard to refute.

[@dampiir8910]

Thanks for all your wonderful videos, I know how much time and hard work can go into these so thank you!

[@Gokatgo]

As soon as I read the news article about the super earth I could not wait for your video! Bonus codyslab points

[@TheJimtanker]

Would a super Earth have a lower Karman line due to the increased gravity?Also,The SLS is a worthless money pit and will probably never fly. Too easy and more cost effective to use companies like SpaceX and Blue Origin.

[@planetrob555]

Before watching the video, I will say that YES, intelligent life on a "Super-Earth", or even intelligent life on a SUN, would evolve to know how to leave their orbit, or at least go into orbit. Why? Because we use what we have available to "us" to evolve. We overcome the obstacles that we are born in to make things...things like vehicles to go into, or leave, the orbit of the world "we" live on. Too many people just think in Earth Human terms. There's a lot more than that....I would surely bet....that exists out there.

[@digitalnomad9985]

You are discussing philosophy. This discussion is about (known) aerospace tech, applied to a different environment. Even if you're right, (And how can we establish whether you are?) you're off topic.

[@DogeFrom2014]

Digital Nomad The discussion of philosophy is highly relevant-if not crucial-to the understanding of applied science. I don't see any reason to refrain someone from bringing up epistemological questions, unless you are one of those people who believe that science and philosophy are completely unrelated (which is not the case...)

[@Exevium]

You went philosophical there... I like it.

[@KaylieRayne]

Another Great video, always learn something watching Scott.. But my question is.. How would someone living on a super earth would know any better? I mean if they had no idea they had a bigger planet or anything, going to orbit would just be normal for them with bigger rockets more power etc. I mean there could be someone out there explaining this to their youtube talking about a planet Earth size using more power to get to orbit. Thats what I love about the verse. Whats normal to us could be abnormal for something else.

[@killacookbook988]

When you talk about a possible intelligent life-form on another plane, it brings up another angle. The society on such a planet may not be fractured like humanity. It could be one big planet with sentient intelligence who can devote as many resources to a space program as needed. They may not have a monetary system, or even governance. It may not be needed. Also when you think of these societal and philosophical weights, you have to account for one more big thing. Humanity may never have been interested in going to space if not for international competition and the war machine. If an 'Alien' civilization didn't have these constructs would they even want, or need to go? It's true that ancient civilizations were fascinated by the stars and built entire cities to track or honor them. It really makes you wonder if intelligence didn't originally come from some cosmic force that we don't understand and can't measure. Or, if humanity and the intelligence on this rock didn't come here from another. I'm KilllaCookBook, Tube safe LOLZ! I love your science videos sooo much because they really challenge me to engage my mind like no text book ever could. Scott Manley for class president!

[@DogeFrom2014]

Such an underrated comment. We cannot understand other lifeforms without understanding the potential bio-social properties first.

[@microproductions6]

Another question: Would other civilizations have access to fuels like hydrocarbons for space travel and energy in general? I guess if there wasn't enough energy around the civilization would die off pretty early, and perhaps an intelligent civilization wouldn't even evolve if the conditions required to make hydrocarbons didn't exist. I guess this all relies on life evolving similar to how it did on Earth, especially plant life.

[@David-zy1lr]

Wouldn't there be much more petroleum due to the higher gravity?

[@microproductions6]

Not sure about due to higher gravity, but maybe due to there being more plants and organic matter because there would be more room to grow.

[@acbthr3840]

If they don't have access to fossil fuels I'd expect that there would be no industrial boom and technological progress would be far slower to start with. You'd probably need to develop rudimentary nuclear, wind or solar power to really get things off the ground.

[@GnanaPrakash86AP]

If there were no natural hydrocarbons, there are plenty of alternatives. They could just as easily focus on artificially made hydrocarbons or other sources of energy naturally available.

[@acbthr3840]

You can't make 'artificial hydrocarbons' without losing energy in the process.

[@NebbieNZ]

What I find amazing about the kepler data is while there was many planets found it was only looking at a very tiny piece of the sky.

[@kerbodynamicx472]

Aliens on a super earth: hmm, anti-gravity is sweet or we won’t make it to space!

[@MsMotron]

motor sports would be awsome thou on a super earth!

[@David-zy1lr]

It would be terrible. Sure it would be cool for downward slopes but they would not get any airtime

[@MsMotron]

so much downforce, such cornerspeeds, so much charge pressure, no need for turbos(probaply much thicker atmosphere)! everything would be awsome for petrolheads!

[@spawnof200]

no need for turbos? ofc there would be, turbos would just work even better!

[@timmytheguitarguy]

with denser atmosphere comes stronger air drag.

[@MsMotron]

also more effective aero and more powerful engines!

[@Shaden0040]

It is possible we are the first civilization that has evolved from life.

[@fred_derf]

The argument can be made that we are likely one of the first civilizations, the first round of stars needed to form, burn out and explode so that the raw materials needed for life could be gathered. So it's unlikely that there was life say, seven billion years ago (I'm likely way off on my stellar ages). But the concept that we are part of the initial phase of universal life is at least plausible. Who knows, another dozen billion years and the universe cold be crowded with life.

[@Shaden0040]

Our Sun is a 3rd or 4th generation star most likely. And since the news that Potassium is needed for life, and that it is rare in the universe at large from what we've found, it is most likely were are the first or one of the first widely separated life forms that has evolved intelligence and a civilization. At least as far as our galaxy goes. Larger galaxies may have life that has evolved intelligence and civilizations already, but they may be beyond our reach as of yet, to detect.

[@ilo3456]

It could also be that expansion is a lot more time consuming than we think or other species just don't have the curiosity we do, or they are in fact trapped in their planets held back by their own planet's gravity, there could be a galactic government that keeps primitive lifeforms blissfully unaware of the galactic situation, they could simply just not bother with us, maybe we are too scary for them, maybe they think we are not ready, maybe they just don't think we are a threat or helpful yet, there are many things we can say of why we haven't found any other sapient lifeforms like us, maybe we are in fact the first wave of lifeforms, and we are lucky enough to be in a planet perfect to propel us outwards, while others are struggling to work in their high gravity planets, while others have gone extinct due to unlucky planetary conditions, it could be that we are merely lucky or there is a higher intelligence creating experiments to find out which lifeforms are the best and then picks them up to be part of their galactic empire and adapts them to this new life. I know that I don't know shit.

[@ilo3456]

Based KekBot Well then tell me the secrets of FTL Travel please? Also if you avoid direct contact with species with technological capabilities far lower than yours, doesn't this make it so that other species are playing a loosing game of catch up since they are developing at most likely a slower or similar rate as the IC is? And is space combat as cool as it sounds or is it lame? Do you have windows in your spaceships? Do you use projectile or energy weapons? What are the requirements to join the IC? Is Earth considered worthy of contact or limited contact? If so what is the criteria the IC uses? Does your species value functionality over aesthetics? Is your species mammalian? Does your species practice religion? How many member species does the IC have? Does the IC have a standing navy or does it rely no member states to act as a sort of military levy in case of conflict? Could I visit the IC if I went through customs? Do you accept Mexican Passports? Could I get accepted into an alien school? What is the state of entertainment in the IC? What is the standard of living in the IC? How old is the IC? I am fascinated to have stablished first contact

[@ilo3456]

Based KekBot Fascinating, but couldn't we move spacecraft immediately at any point through simply moving between dimensional spaces? If we let's say wanted a spacecraft to move from one end of the Galaxy to the other, couldn't we simply plop a piece of the Space-Time Continuum and move it to another section of space, by moving between dimensions and instantly arriving at the destination?

[@GreyDeathVaccine]

You savage! You killed those poor Kerbals deliberately.

[@nicosmind3]

*Thanks Scott,* I've been wondering this question for years now :)

[@HurricaneSA]

The problem with these kind of questions is that we necessarily have to make certain assumptions which may be completely wrong. For example we're assuming that these aliens are at the same level of technological and scientific development that we are at. For all we know they could discover a super light metal or they could simply be more scientifically advanced and have figured out a better way of getting rockets off the ground than using copious amounts of fuel. I guess what I'm saying is that just because we don't have the means to do something does not mean every alien race are bound by the same shortcomings in knowledge. As for why aliens haven't popped in for a cup of tea, I think it's simply that we're very far from these possible habitable planets. They might be able to get off their planet just fine but they would be bound by the same laws of physics (as we understand it) so they wouldn't be able to travel faster than light and would thus have to invent the warp drive first. And even if they did invent the warp drive they'd have to know we exist. We only started broadcasting radio signals about a hundred years ago so it will be a long time before their equivalent of SETI discovers our little planet has a few intelligent people on it. ;)

[@ricomotions5416]

true

[@fred_derf]

The assumption isn't that the alien race is at our level of technology, it's a hypothetical of an alien race that has reached our level of technology. If you're going to propose an advanced unknown (to us) technology to get off the super-earth you might as well just call it magic. Oddly you attribute a magic technology to the hypothetical alien race to get off-planet but then restrict them to the known physical laws once they are in space. Even if such an alien race found a lightweight metal equivalent (say carbon fiber) they are still bound by the physical laws of chemistry. Hydrogen and oxygen combining isn't going to produce any more excess energy per mole on super-earth than here on earth. Their best bet for getting off planet may be nuclear (orion?) or some kind of ground-based-laser powered ablative engine. If their atmosphere was a lot higher in oxygen they may be able to save considerable weight by using a first stage atmosphere breathing rocket engine.

[@HuntingTarg]

So what you're really saying is, that we're asking the question "could WE launch a rocket into orbit from a super Earth?"

[@HurricaneSA]

I'm not saying they would have magic to get off the planet but we don't know what minerals exist on their planet hence my supposition that they might have access to some materials and/or fuel we don't. I'm also not saying they won't have warp like technology for sure but rather that that would be a greater problem to solve than getting off a heavy planet.

[@horacefairview5349]

We know all the good minerals already though. Physics is still the same for them. According to physics rockets are one of the very few ways of getting to orbit, they'd still have a de laval nozzle and would probably use hydrogen too.

[@clearlyepic9958]

Love how Scott Manley archives are being recommended to me now after Inspiration4… yeah, great point! The Fermi Paradox could just come down to simple physics of escaping a planet.

[@sandercohen5543]

The music in this is spot on. Spacey and chill, without that disney vibe. I put it on repeat when going to bed ^^

[@jerrysedlacek6354]

Thank You, definitely one of your best videos !

[@Skrillfreak]

What a great video. I had no idea that this planet was discovered by transit photometry. Also RIP Jebediah.

[@iamzid]

I had a limited amount of time and a dozen videos in my box. I could only watch one of the videos. I chose yours.

[@terapode]

Your videos are always very educational.

[@skuzlebut82]

I love what you do, Scott. Every video you produce is top notch. Aside from that, I wonder and I do believe that it is possible for another form of life to evolve without the need for water. We're looking for what it takes for life as we know it on Earth, however, who knows, after billions of years, life may have found a way using other elements and molecules. The ideas are endless and you sir, help us all keep an open mind.

[@carlosguevara5154]

I havent seen the video, but judging from the title.... THIS IS FREAKING AWESOME TOPIC... THANK YOU

[@thePronto]

Scott Manley - you are the science teacher I never had. But to be fair, my science teachers didn't have the tools you have.

[@herbertkeithmiller]

YOU SENT THEM UP KNOWING THEY WERE GOING TO DIE! Brave, noble kerbls to make such a sacrifice.

[@aaronsarnat]

Haha love the ending of this video. RIP Jeb & Bill!

[@rafeller9057]

I'm getting to you a year after the publish date, but I would love to see you do one on the most optimal planet for hosting a spacefaring civilization.

[@johnmanderson2060]

Good topic ! This factor is vital for selecting future missions to other planets 🪐

[@rayceeya8659]

Hey Scott, love the video, seems really topical right now, but got me thinking, twice the radius, and twice the gravity, how do these compare to twice the payload? Fiddling with those variables, which one requires the most or least launch vehicle. Just a passing thought.

[@njrasmussen5515]

Very good video you snuck some science in there LOL not just playing a game awesome

[@favesongslist]

Thanks so much for this, It is a problem that has been on my mind every time these super Earths being discovered, so interesting to know at 2x Earth's gravity it is possible to launch a satellite using chemical powered rockets. Could you do an analysis for nuclear powered rockets pls.

[@wallyhare8616]

Scott Manley i just want to know what program you are using

[@orchdork775]

I feel like a great movie or book plot would be some astronauts landing on a super earth knowing once they get there they can never leave. Maybe earth is no longer habitable and humans are living in a huge spacecraft in the search for a new planet, so the astronauts go investigate the super earth to see if it's habitable before trapping all of humankind on it. Could be a cool story.

[@powersurge91]

@scott Manley, I am wondering if the intro jingle with the Ukelele was made by Skye or just from a music production program?

[@scottmanley]

It was me.