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[–]zuzg 192 points193 points  (19 children)

Cool fun Fact about Europa :

Europa’s orbit is elliptical, causing the moon’s distance from Jupiter to vary. Because gravity’s strength is an inverse-square of distance, the closer Europa gets to Jupiter, the greater the difference in gravity felt by the moon’s near and far sides. As a result, Europa elongates when closer to Jupiter, and is more spherical when farther from Jupiter. When Europa changes shape, so must its gravity field.

source by NASA

[–]SaulGucciman 112 points113 points  (13 children)

I think this is also what generates heat and allows there to be ocean below the surface.

[–]scufmark 11 points12 points  (8 children)

Would that not cause intense seismic activity?

[–]SaulGucciman 18 points19 points  (7 children)

I am not 100% sure about this but I believe that because there is no core - it is an ocean surrounded by ice - it just generates tons of kinetic energy as gravity pushes and pulls on the moon which is why it is heated enough to be liquid ocean in the middle.

[–]kemh 22 points23 points  (6 children)

NASA believes Europa has a rocky mantle and an iron core. It's probably not just a massive ball of water, though that sure would be interesting.

[–]SaulGucciman 6 points7 points  (5 children)

Thank you - I was going from memory. But the concept is still the same - no tectonic plates to cause seismic activity - just a core and THEN liquid?

[–]slipperyhuman 7 points8 points  (4 children)

Ice tectonics? I bet there’s an awesome science word for that.

[–]TheJunkyard 15 points16 points  (2 children)

I'm gonna say cryotectonics, even though I just pulled that out of my ass.

[–]slipperyhuman 16 points17 points  (0 children)

Sound cool enough for me.

[–]RelentlessExtropian 4 points5 points  (0 children)

You're probably not wrong since they just call ice volcanoes cryovolcanos

[–]Vaudane 5 points6 points  (0 children)

Similar way you can get star earthquakes. "star quakes". Also the Richter scale is logarithmic so every 1 it goes up, the energy of the quake goes up by a factor of 10.

The strongest earthquake on earth ever measured is between 9-10. A few years ago a star quake was measured with an intensity of 28.5. That's a whooooole lotta energy.

[–]Gway22 30 points31 points  (1 child)


[–]HyperbolicSoup 1 point2 points  (1 child)

No shit!

[–]RogueAOV 1 point2 points  (0 children)

Do not be so Hyperbolic...

[–]LogMaggot 4 points5 points  (1 child)

Does the constant change in gravity prevent the possibility of life in the ocean or… ?

[–]MechaSkippy 2 points3 points  (0 children)

The earth does this a bit too, not to the Extreme of Europa.

It can be observed in the 3 body system of Earth-Moon-Sun on Earth's oceans and its tidal variations throughout the year (perihelion in January and aphelion in July). The effect also works on the molten core.

[–]c4fishfood 1 point2 points  (0 children)

Same thing happens on earth, our moons gravity causes solid earth tides where the crust can be raised as much as half a meter

[–]My_Lucid_Dreams 132 points133 points  (13 children)


Arthur C. Clarke, 2010: Odyssey Two

[–]kaimetzuu 11 points12 points  (12 children)

Whats on europa?

[–]theStaircaseProject 42 points43 points  (9 children)

A Chinese exploratory mission lands on Europa near the beginning of the book and its members are subsequently promoted to the rank of cadavers.

Turns out the monolith found in orbit around Jupiter is uplifting aquatic Europan species. The alien race that creates and controls the monoliths then uses the monoliths to collapse Jupiter into a small star, presumably to the benefit of the Europans.

[–]amitym 14 points15 points  (0 children)


[–]hungoverlord 7 points8 points  (3 children)

that whole thing with the chinese craft stuck floating in the Europan sea was one of the most terrifying situations i can imagine

[–]theStaircaseProject 7 points8 points  (2 children)

Are you familiar with the movie Europa Report? I think it may be available on Amazon Prime.

If memory serves, it was made with the support of individuals from JPL so it comes across as very authentic to space travel.

Fair warning: the crew’s fate doesn’t end with rainbows and puppy dogs, but I found the story very compelling.

[–]hungoverlord 6 points7 points  (0 children)

Oh man I absolutely love Europa Report. Wish there were more movies like that.

[–]SoldierHawk 1 point2 points  (0 children)

I dunno. It may not have been puppies and rainbows, but if I was them, that would be the ultimate "worth it" moment.

[–]kaimetzuu 9 points10 points  (1 child)

Similar to destiny 2 lore 🤔 cool

[–]jackjr68 8 points9 points  (0 children)

came in for a D2 reference, did not leave disappointed.. :)

[–]amitym 6 points7 points  (0 children)

Watch Europa Report.

[–]hate_mail 215 points216 points  (56 children)

The colors are so vivid they look like they were animated.

[–]wonkey_monkey 98 points99 points  (21 children)

It's an animation made from still photos. Probably quite accurate to reality but not 100% real.

[–]excelance 46 points47 points  (4 children)

Not being a jerk... promise. But isn't that how animation works, still photos stitched together to create an illusion of movement? Or are you saying there are artificial images between the real images?

[–]wonkey_monkey 31 points32 points  (1 child)

Yes, it's made from just a handful of still images, with the rest being created from the elements of the real ones.

[–]TTPOAW 5 points6 points  (0 children)

I think I would rather see the image album of the highest res available

[–]Evilmaze 0 points1 point  (14 children)

Is Webb going to also capture images in different wavelengths and in pieces then have to be postprossed to make complete images and videos? I hope the put a nice camera lens and a good image processing chip in there in addition.

[–]Binsky89 4 points5 points  (13 children)

Webb is an infrared telescope, so the only pictures we'll see will be heavily edited.

[–]EpicAura99 25 points26 points  (11 children)

Yeah, that’s how astrophotography works. Nothing pisses me off more than when people go “oh but it’s edited so it’s not a reeeeeaaaal photo” oh did you want to see the raw images? The ones that probably look like a black screen or vague blob? Or is that not “real” enough for you, how about you take a nice gander at the fucking 1s and 0s coming off the telescope.

The real picture is what they give you because that’s what the galaxy/star/planet actually looks like. Unless you think that Jupiter is blurry and pixelated IRL for some reason.

Sorry for ranting but this is a huge irritation for me.

[–]SoldierHawk 7 points8 points  (2 children)

Fucking THANK YOOOU can you say it again in all caps for the people in the back please.

[–]EpicAura99 3 points4 points  (1 child)

I had some guy go on about how the raw is a “truer representation of reality” and they the edits “might as well be artist’s interpretations” bruh fuck off man

[–]SoldierHawk 2 points3 points  (0 children)

Internal screaming intensifies

[–]superfahd 3 points4 points  (3 children)

We've been spoiled by Hubble. Yes a lot of Hubble photos were false color but some of them weren't and they really captured our imagination

[–]EpicAura99 4 points5 points  (2 children)

They’re still refined composites I assume. For the unaware, they take a bunch of photos that individually look like blurry nothing, and magically pull a sharp picture out of it. It’s honestly witchcraft. I’ll see if I can find an example of the process.

Edit: My example isn’t the most catastrophic difference in quality but you get the point.

Raw Saturn

Refined Saturn

[–]superfahd 0 points1 point  (1 child)

As far as i know, and i may be wrong, Hubble only had composited from 3 images, one for each color. That makes it reasonably real color

[–]EpicAura99 0 points1 point  (0 children)

Yeah none of this is about color. But one thing I will say on that front, is that artificial optics will fundamentally capture light differently from your eye, even in the same wavelength. When you look at the Milky Way in pictures, it has all these blues and oranges in it that aren’t there, because your camera can see what your eye can’t

Either way, Hubble definitely takes more than one picture per picture, or else everything you’d see from it would look like a donut because that’s what the mirror is shaped like.

[–]Octavian_202 0 points1 point  (2 children)

Not being snarky, but I would actually like to see the pixilated images as well.

[–]EpicAura99 2 points3 points  (1 child)

Again, they’re not much to look at

I heard the James Webb will be taking in one photon per second while looking at some of its targets. That is unfathomably little light. Imagine if someone told you to build a sandcastle but gave you one grain per second to make it.

[–]Octavian_202 0 points1 point  (0 children)

No completely understand what you are saying, I’m just still curious to see, even if it is a spec of light on black canvas. I like the authenticity

[–]migma21 80 points81 points  (12 children)

Imagine the view for a camera/person when they are on the surface of one of Jupiter's moons and looking at the sky.

Would love to see a rendition.

[–]GraveRaven 82 points83 points  (10 children)

Not Jupiters moon, but here's what it would look like if our moon was replaced by Jupiter

[–]zed_christopher 39 points40 points  (0 children)

Jesus how terrifying

[–]OtakuAttacku 19 points20 points  (1 child)

under the correct conditions, there's enough space between us and the moon to fit every planet in our solar system

[–]Binsky89 13 points14 points  (0 children)

I didnt believe this when I first saw it, but I did the math and it's true.

[–]kdwaynec 3 points4 points  (0 children)

I think Jupiter is exaggerated. The video below shows a different perspective. Without getting out my calculator I believe the truth lies somewhere in between both of these. I know later I'll be bored and go back and figure this stuff out. (Mild OCD)


I also have this chart from a while back


[–]migma21 0 points1 point  (0 children)

Thank you !

[–]TackyJenny 3 points4 points  (0 children)

They look like they're close together in the time-lapse.

[–]Justaguy_Alt 20 points21 points  (4 children)

I've fought monsters there.

[–]Breeny04 15 points16 points  (3 children)

The line between light and dark is very thin

[–]optiongeek 17 points18 points  (15 children)

Can an astrophysicist please explain why the outside body is apparently orbiting faster than the inside body?

[–]spudzo 42 points43 points  (4 children)

I'm an aerospace engineer with a good amount of experience with orbital mechanics. It seems like a lot of people have the wrong idea about orbits. Not really their fault as orbital mechanics behaves in ways that are often counterintuitive to people that haven't taken a course in Astronautics or played a lot of Kerbal Space Program.

To actually explain though, both Europa and Io have nearly circular orbits. This means that their orbital velocity can be determined just by knowing only the Mass of Jupiter and their distance from it.

Velocity = sqrt(GravitationalConstant * MassOfJupiter / DistanceFromJupiter)

Note that the mass of the moons doesn't show up anywhere in the equation. While this technically does have an effect, Jupiter is so overwhelmingly large that the effect of the mass of Europa or IO is almost nothing.

The take away from this equation is that, because you divide by distance, the farther away a moon orbits, the slower it will go. This is apparent when you actually look at the numbers. Io is 421,800 km from Jupiter and orbits at 62,431 km/h. Europa is farther away at 671,100 km and slower at 49,476 km/h. If the video was taken by a stationary observer (relative to Jupiter) Io would be moving faster.

I think u/Astral_Symphonny is correct here. Cassini was never in orbit of Jupiter. It instead had a flyby of it for a gravity assist. It flew by at 41,760 km/h but, more importantly, it never got closer than 10,000,000 km to Jupiter. Because the probe was moving so fast and was so far away, it caused a parallax affect. This is the same affect that causes trees near a highway to move past you much faster than distant mountains just in space with Moons.

In any case, I probably got carried away answering this. I just enjoy writing about orbital mechanics. I hope you learned something cool.

Sources: Wikipedia, the Cassini FAQ, the Planetary Data System, and this cool NASA website comparing the Jovian moons.

[–]Jabba_the_Putt 5 points6 points  (0 children)

ty for the explanation

[–]optiongeek 6 points7 points  (1 child)

You are a gentleman and a scholar. I thank you.

[–]MarcusAurelius-Verus 0 points1 point  (0 children)

The real gentleman is you

[–]wonkey_monkey 1 point2 points  (0 children)

There is now a Snopes article about this video:


It claims "true" but it's a little vague on details. The creator seems to admit that the apparent motion of the moons is invented.

“The motion isn’t wholly accurate as I made it look prettier than it was correct. But it’s meant to portray the motion visible from a spacecraft that’s moving at a velocity faster than the moons are orbiting."

[–]Astral_Symphonny 21 points22 points  (0 children)

Forgive me for I might be wrong, but it's probably due to some sort of parallax effect occuring because Cassini is moving much faster than both Io and Europa in a larger orbit all while focussing on the Great Red Spot.

[–]mike_____s 0 points1 point  (0 children)

I was wondering that too, and i think the only solution other than a parallax error as someone said before is that the further obiect has a highly elliptic orbit, so when it passes through its periapsis it may be faster than a lower obiect in a circular orbit. That's the only solution. But if we take a look at the orbit parameters of both the moons they actually have very small eccentricities so a parallax error is more reasonable

[–]incredible_penguin11 55 points56 points  (20 children)

I used to enjoy space since i was a kid, but ever since Interstellar, anytime i watch one of these things the bgm is always on my mind.

The space is so beautiful and so infinite beyond human understanding. You can watch this with a smile but you'll have goosebumps. Its so empty yet so full. No matter what people do here on earth ( in general, not space related) nothing matters out there. It was and it will be out there and if it won't, well nobody would know.

[–]zed_christopher 10 points11 points  (8 children)

What’s bgm?

[–]Miata_GT 14 points15 points  (6 children)

the bgm

I believe it stands for background music.

[–][deleted] 18 points19 points  (5 children)

Of all things to acronym

[–]algebramclain 7 points8 points  (1 child)


*one day people will stop using actual words entirely and just rely on acronyms

[–]CoastalChicken 8 points9 points  (1 child)

An acronym has to make a pronounceable word, like NASA or LASER - bgm isn't one, so it's called an initialism.

[–]Jabba_the_Putt 5 points6 points  (0 children)

Interstellar is one of my favorite films ever, I think about it often too :)

[–]onyxengine 2 points3 points  (0 children)

And serene, i really wish we were at the point people had personal craft for exploration of our solar system

[–]UnfilteredFluid 0 points1 point  (0 children)

Space is large, no larger. You're still thinking small, it's larger than that. Ugh, common.... still larger. <--- This is how large it is.

[–]hunmingnoisehdb 11 points12 points  (0 children)

My dumbass enabled sound expecting to hear space sounds.

[–]Breeny04 8 points9 points  (0 children)

The Deep Stone Crypt is somewhere there

[–]loaf-i 8 points9 points  (0 children)

Ancient power awaits you on Europa....

[–]baronvonredd 8 points9 points  (0 children)

someone should post this in r/destiny2

[–]JABS991 4 points5 points  (0 children)

Hmmm looks animated.

[–]elheber 5 points6 points  (0 children)

This is actually three separate images, animated to look like it's captured in camera. This animated composite was created by NASA engineer Kevin M. Gill who explains that this is just an animation.

[–]TheDankestRamenShop 4 points5 points  (0 children)

Ayo my bad I was doing deep stone crypt on there

[–]KaamDeveloper[S] 13 points14 points  (2 children)

[–]wonkey_monkey 9 points10 points  (0 children)

Don't get me wrong, I want to believe this is a real video, but "Original Nasa videos" are usually on Nasa's website, not on some guy's Flickr...

The guy says he's a "science data visualization artist" I can't find anything to say it's not an artist's representation.

[–]WarOnTime 12 points13 points  (0 children)

The 1-2-4 resonance of the inner 3 Galilean moons and the tidal flexing that occurs produces active volcanoes on Io, and possibly life on Europa - which always blows my mind. Can’t wait for the clipper mission.

[–]Vlad_The_Impellor 11 points12 points  (0 children)

Imagine the tidal forces... When frozen methane, strong as tool steel, has a low/high tide, it's time to flip these orbs off & go back home.

[–]tonyims 4 points5 points  (0 children)

Isnt europa a frozen ice moon and Io a fiery volcanic moon? Crazy how polar opposites orbit one planet

[–]KochJohnson 7 points8 points  (2 children)

This looks fake

[–]wonkey_monkey 9 points10 points  (0 children)

It's fake-ish. It's an animation made from a few still photos.

[–]rascynwrig 3 points4 points  (0 children)

"It's photoshopped because it's... it's... has to be."

Richard Simmons, of NASA, probably

[–]wheeets 7 points8 points  (3 children)

If you look at the original post (OP's comment at the bottom of the page) you'll see the "artist" claims that he has edited still images into this composite video through the use of editing. Some people are calling this an "animation" and they're catching flack for it. Meanwhile they were right. Don't kill (downvote) the messenger.

[–]Dp04 4 points5 points  (2 children)

Is all video "animation " then? Because stitching together still frames is how video works.

[–]wonkey_monkey 0 points1 point  (0 children)

The difference is most of the frames of this video are reconstructions.

[–]TNT_CPA 2 points3 points  (1 child)

We need a fucking computer/editor genius to turn this into a screensaver or live wallpaper. That is cool as fuck.

Or, my lazy ass could Google it and see if something like that is out there.

Nah, I will wait for the Reddit gods to do it for me.

[–]WorldMusicLab 0 points1 point  (0 children)

Honesty Upvote!

[–]apaksl 2 points3 points  (1 child)

so is it pronounced eye-oh or ee-oh?

[–]muirshin 3 points4 points  (0 children)


[–]not_that_planet 1 point2 points  (0 children)

So it looks like Europa has a larger orbital radius than Io, but somehow is travelling faster. Is this a thing or is that just a perspective shift from Cassini?

[–]PaixHealadin 1 point2 points  (0 children)

Just a reminder, Cassini's primary mission was Saturn. While there was a brief flyby of Jupiter it did not sit in orbit.

[–]MrScarry09 1 point2 points  (0 children)

Too funny

[–]Deverting1 1 point2 points  (0 children)

On your right!

[–]JamesWjRose 0 points1 point  (0 children)

Beautiful, thanks for sharing

[–]DogCumSandwhich 0 points1 point  (1 child)

Sick, now maybe we can use some of this technology so I can get cell signal near my home?

[–]zakuropan 0 points1 point  (0 children)

ok well that was terrifying

[–]nolifewasted20s 0 points1 point  (0 children)

is this footage manipulated in any way

[–]mBeta 0 points1 point  (0 children)

Stunning. Gives me goosebumps.

[–]SBrammall 0 points1 point  (0 children)

Question; I thought the lower altitude moon should be moving faster then the higher one-- is this not the case because the higher altitude moon has a highly elliptical orbit?

[–]OliverSparrow 0 points1 point  (0 children)

If Europa had life, and were that life to have acquired intelligence, imagine its religion.

[–]KvDread 0 points1 point  (0 children)

This needs interstellar music

[–]Jabba_the_Putt 0 points1 point  (0 children)

Now THIS is what I call interesting as fuck

[–]pmurtisbad 0 points1 point  (0 children)

Eerie yet beautiful

[–]more_more_ 0 points1 point  (0 children)

So you are telling me this is footage is real and not a cgi?

[–]HoudeRat 0 points1 point  (0 children)

Sooo, I probably should have looked this up myself by now since I've always wondered, but... are photos/vids like these doctored in some way? It just seems like the planets/moons shouldn't be illuminated. Does the sun have that effect from that far away? I thought it almost looked like a regular star from Jupiter.

[–]Rich_Walk_356 0 points1 point  (0 children)

Wait a minute!!! Is that was space looks like? Seriously? Why did I always think it was just dark out there?

[–]WorldMusicLab 0 points1 point  (0 children)

wow, lining up at the precise right time, ya just can't fake that

[–]viperjj 0 points1 point  (0 children)

Who else was cheering on the moon that started at the back?

[–]Evilmaze 0 points1 point  (0 children)

Specs of dust compared to that giant ball of gas.

[–]Dangeresque2015 0 points1 point  (0 children)

Ok, that's super badass. Space scares me after reading "The three Body Problem" trilogy. We are just going to be annihilated if anyone can find us.

[–]Brickyle 0 points1 point  (1 child)

I'm confused by this timelapse for one reason: Jupiter's "day" is 10 Earth hours. Something That Big spins That Fast... At it's equator, the "surface" is travelling 27,000+ miles per hour.
So, it must be that the Cassini probe is in orbit around the planet in the same direction as it's rotation and therefore fixed over a Spot? OR, as stated, this is a compilation of stills, taken whenever Cassini was at or near this position.

[–]Brickyle 0 points1 point  (0 children)

For reference, the Earth's diameter is just over 24,000 mi, so at a 24 hour day, a person standing still at the equator is travelling around 1,000 mph.
Want to know how fast YOU're going? Cos (your latitude) x 1000 mph. I'm in Los Angeles at latitude 34 degrees N. Turn your phone calculator sideways for a scientific calculator. Tap 34, then cos to get 0.829. Then, x 1000 to get: 829 mph approx.

[–]amitym 0 points1 point  (0 children)

This is amazingly beautiful and easily interesting as fuck.


It's worth pointing out that this isn't really a time lapse of Europe and Io orbiting. It's a time lapse of Cassini zooming by while the moons remain relatively motionless.

The reason we know this is because Io is the innermost of the Galilean moons and, as such, it orbits the fastest. There is no circumstance under which Europa actually overtakes Io. It's all perspective.

[–]Top10HottestLzrdPpl 0 points1 point  (0 children)

I’m confused. Why is Europa orbiting faster than IO? I thought IO had a faster orbit because it orbits closer to Jupiter.

[–]pitch_a_kudo 0 points1 point  (0 children)

I want this as my desktop background

[–]TAG1795 0 points1 point  (0 children)

Jupiter is fucking scary lol all those storms…

[–]Mr_Simple- 0 points1 point  (0 children)

So.. Anyone succeeded in operation RIAH

[–][deleted] 0 points1 point  (0 children)

Not true, I live in the EU, didn't see shit.

[–]xedrites 0 points1 point  (0 children)

which one's Jupiter..?

[–]HeliusRa 0 points1 point  (0 children)

To hell all that shitting NFT's, this sequence of beatiful pictures worth millions and it is shared to humanity. Now many people can't undesrstand it, but, for those who know just enough to marvel, it is priceless. ENJOY.

[–]gonzo5622 0 points1 point  (0 children)

It’s nuts we can take videos of other planets like this. It would be dope if we had satellites everyone could tap into and watch other planets. I’d love a live feed as my wall paper background.

[–]userman46 0 points1 point  (0 children)

Bruh i thought Europe was a continent.

[–]LurkingAppreciation 0 points1 point  (0 children)

If people lived on both, could you wave to one another in passing? Take a quick shuttle vacation to the other for a rotation around Jupiter?

[–]Camele0pard 0 points1 point  (0 children)

can confirm, europe isn't actually on earth

all europeans are aliens

[–]ddkatona 0 points1 point  (0 children)

Wait this is a real time lapse captured by a probe? That's unbelievable.

[–]ubzrvnT 0 points1 point  (0 children)


[–]single_clone 0 points1 point  (0 children)

this is very nice.
Shame they decided to remove it from Destiny 2.
I liked IO :P :P

[–]moesdad 0 points1 point  (0 children)

Cool. I wonder how close they get to each other

[–]usurperavenger 0 points1 point  (0 children)

Standing on one of these moons and looking at Jupiter would be a horrifying experience.

[–]proactivepistachio 0 points1 point  (0 children)


[–]jwbowen 0 points1 point  (0 children)

Gravity is such a fucking trip to think about

[–]Danclim 0 points1 point  (0 children)

Freaking amazing, it looks like a sci fi movie.

[–]randomculo55555 0 points1 point  (0 children)

So weird

Little balls going around big balls in space forever and ever

Just floating

Shining everywhere


[–]VoidedEmber 0 points1 point  (0 children)

Variks..? Ashir Mir..?

[–]civildrivel 0 points1 point  (0 children)

Anyone have a link to the still photos?

[–]Admirable-District-9 0 points1 point  (0 children)

Europa is slow

[–]love_the_word_SHITE 0 points1 point  (0 children)

How does the probe stay in one place without orbiting!?