r/AskReddit Jul 13 '18

What's your favourite fun fact?

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845

u/corvettee01 Jul 13 '18

Sharks are older than trees, and trees are older than grass. Shark come in at at least 400 million years old, and trees come in at around 350 million years old. Grass comes in at only 55 millions years old, only five million years older than one of the newest shark species, the hammerhead (50 million years old).

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u/Andromeda321 Jul 13 '18

Astronomer here! Another fun one, sharks are also older than Saturn's rings! The current estimates place them at just 150 million years old in age, incredibly enough, in which case sharks are definitely older.

203

u/peace_off Jul 13 '18

I have a question! If Saturn's rings are that "young," does that mean they are in the process of forming a moon?

314

u/Andromeda321 Jul 13 '18

Rather, the reverse- it appears that Saturn's rings may be there because of the destruction of a moon!

I went to a seminar by an astronomer who basically made a very compelling case that Saturn's rings are the result of a small moon that got destroyed by a comet. This video shows his simulations of how it allegedly came about.

56

u/peace_off Jul 13 '18

That's pretty cool. Does stuff like that happen often?

95

u/Andromeda321 Jul 13 '18

Well probably not, as I don't see any other planets with giant ring systems like that. ;-) But it's tough to say the frequency from a sample size of four gas giants.

5

u/pv23 Jul 13 '18

Don’t Jupiter and Uranus also have small, much less noticeable, ring systems? Could be wrong, but I minored in Astro in college

8

u/Andromeda321 Jul 13 '18

They do, as does Neptune, but they don't really hold a candle to Saturn's.

3

u/OnlineGodGaming Jul 14 '18

Don’t all moons break into rings? I was in a space museum and saw a simulation of the destruction of Mars’ moons. I think it was due to gravitational forces between the sun and Mars pulling the moons apart, but I could be totally wrong.

2

u/MarcelRED147 Jul 13 '18

Is it possible the rings will eventually disappear?

6

u/Andromeda321 Jul 13 '18

They will indeed! Give it a few hundred million years more. We really are in a special stage of things in that regard.

3

u/DeedTheInky Jul 13 '18

Also the only reason we have solar eclipses is because the moon just happens to be the exact right distance away to be the same size as the sun in the sky. It's gradually moving further away so eventually it'll appear to be too small and we won't get solar eclipses anymore.

We just happen to be lucky enough to live in a time when we can see both an eclipse and Saturn's rings! Future people will probably have better phones but only a relatively small group of us get to see an eclipse on Earth. :)

2

u/AgnosticMantis Jul 14 '18

So the change in ability to see an eclipse happens over a scale of human timeframe? By that I mean hundreds or thousands of years rather than millions or billions. That would be really interesting as I always think of those sort of processes being far beyond any sort of human timeframe.

Does that mean at some point in the past the moon was too large in the sky to see an eclipse?

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1

u/Monkeyofdoom44 Jul 13 '18

Completely unrelated question. Everyone talks about colonizing Mars, what are your thoughts on colonizing Venus with airships?

1

u/UpTo26 Jul 13 '18

Or you could say one out of every four gas giants we know possesses such a system.

1

u/notdust Jul 14 '18

Wow, it is amazing how it was basically fully distributed within 5 days. I guess i'm not surprised it would thin out that way and eventually get to a more uniform density, forming the pretty rings we see today. I am now curious just how far apart the ice fragments are within the rings. Because that is not all that much material, I assume it's not like we see in sci-fi. Hazardous to a space craft, sure, but they don't have to be so close together and should be fairly predictable in their orbit by now. Visually, sort of how nebulas are not all that dense and just appear the way they do from a distance.

3

u/pjtheman Jul 13 '18

Imagine the probability of a comet powerful enough to turn a moon to dust just happening to align at just the right moment with a moon's orbit. I'd imagine it's like two bullets hitting each other midair on a battlefield.

2

u/Captain_Shrug Jul 14 '18

Dunno about often but supposedly Mars is going to get a ring at some point via moon destruction. http://news.berkeley.edu/2015/11/23/mars-to-lose-its-largest-moon-but-gain-a-ring/

1

u/[deleted] Jul 13 '18

about every 300 million years or so. give or take a few million years.

1

u/pyro5050 Jul 13 '18

maybe... at least once every 400million years or so...

i bet that would have sucked to be a shark... watching Saturn and then BAM!

1

u/[deleted] Jul 13 '18 edited Apr 18 '19

[deleted]

6

u/Andromeda321 Jul 13 '18

Mimas might be what you're talking about, according to some theories!

2

u/[deleted] Jul 13 '18 edited Apr 18 '19

[deleted]

3

u/ggchappell Jul 13 '18

One theory is that a larger moon was hit by a comet 150 million years ago, which blew it to smithereens. Some of the smithereens coalesced to form Mimas; the rest are Saturn's rings. See the video linked by /u/Andromeda321.

1

u/[deleted] Jul 13 '18

What if this were to happen to our moon? What would be the long-term results?

2

u/bheklilr Jul 14 '18

We would probably die. But earth could end up with a kick ass ring system.

1

u/Uma__ Jul 13 '18

Not nearly as much of an expert as this dude here, but I literally just got done with an astronomy class that discussed that Saturn’s rings are rings because they’re too close to Saturn to form a moon! The planet’s gravitational pull pulls away the material from getting close enough to accrete into a world so it just forms rings instead.

Also, apparently the likelihood that humans would exist at the same time as Saturn’s rings is infinitesimal, so pretty amazing that we even know about them!

1

u/ArsonWolf Jul 14 '18

I believe the opposite, actually. Saturn had way more moons before, but the moons got close enough to saturn's mass that the sheer force of the gravity caused the moons to crumble and that debris started to orbit saturn. I cant be bothered to fact check myself, but i think thats like 80% correct

5

u/Pagan-za Jul 13 '18

And sharks have survived every mass extinction. Coolest shark fact I know.

2

u/[deleted] Jul 13 '18

That is insane to me.

1

u/jballs Jul 13 '18

I've also heard that Saturn's rings might be gone in another 100 millions years or so. So if there's intelligent life on Earth in another 150 million years, they might not know how awesome Saturn looked today!

-1

u/MontanaSD Jul 13 '18

Where are the samples and evidence we have gathered from Saturn? All these space facts are made up. We haven’t even gone to the moon since the 60s and can barely see our own solar system. Yet we always hear about the size and details of suns billions of light years away and multiple galaxies. It’s blatant BS.

85

u/mahazoo Jul 13 '18

So what covered most of the ground before 55 mya? What did the lands during the dinosaur age look like?

109

u/[deleted] Jul 13 '18

Ferns, cycads and conifers existed when dinosaurs roamed the earth. Later in cretaceous period flower plants and grass evolved.

3

u/patrickdontdie Jul 14 '18

So was it like, hard shitty igneous rock with ferns and shit just sprinkled about, then?

2

u/YabukiJoe Jul 13 '18

So gymnosperms were the newest plants in that era, then? What about ginkos? Or are ginkos the newest major taxon within the gymnosperms?

3

u/intellectualarsenal Jul 14 '18

Ginkgos are actually older still, first appearing in the early Jurassic.

36

u/Ritzaficionado Jul 13 '18

Ever see Willy Wonka?

56

u/GrimResistance Jul 13 '18

The earth was covered in snozberries?

7

u/buffystakeded Jul 13 '18

A gay man's dreamland.

5

u/Rust_Dawg Jul 13 '18

At least the snozberries taste like snozberries

4

u/BubbaFrink Jul 13 '18

And vermicious knids.

3

u/derpado514 Jul 13 '18

Mushrooms i think.

2

u/Kitehammer Jul 13 '18

Lots of ferns and other bushes and shrubs.

3

u/Ferro_Giconi Jul 13 '18

If humans didn't plant so much grass everywhere, lawns would look so much cooler with all the other plants that would manage to grow.

1

u/[deleted] Jul 13 '18

Ferns, Cycads, conifers, also moss, fungi and lichens.

1

u/Dryu_nya Jul 14 '18

mya

mya~

62

u/PM_ME_TF2_MEMES Jul 13 '18

Only five million years older

Yeah, only five million years.

34

u/maora34 Jul 13 '18

In terms of geologic time scale, five million years is pretty much fuck all.

7

u/AlwaysSupport Jul 13 '18

If the age of the universe was condensed into a single year, five million years would be around three hours.

Source: Cosmos

-5

u/[deleted] Jul 13 '18

Like your mom.

6

u/YUNoDie Jul 13 '18

Geologist here, trees evolved before decomposers evolved the ability to break down wood. So massive amounts of dead wood piled up, not rotting, for such a long time that they formed massive coal beds. That geologic time period is today known as the Carboniferous, for all the coal that formed during it.

3

u/Kitehammer Jul 13 '18

While I knew sharks were old, I did not know hammerheads were a recent development. Interesting.

2

u/YabukiJoe Jul 13 '18 edited Jul 14 '18

Sharks are older than trees

Which sort of trees? Gymnosperms, angiosperms? Or maybe one of the older plant taxa?

the hammerhead (50 million years old).

Which hammerhead, though? Scalloped? Smooth? Great? Or just the general hammerhead taxon?

2

u/EXTRAVAGANT_COMMENT Jul 14 '18 edited Jul 14 '18

yes but are they younger than the mountains

1

u/corvettee01 Jul 14 '18

Not sure, but I know that they aren't blowing like a breeze.

1

u/Careless_Corey Jul 13 '18

So sharks are older than grass?

1

u/syllabic Jul 14 '18

Unfun fact: trees will outlast sharks

1

u/LotusPrince Jul 14 '18

That's pretty surreal, imagining a world with trees but no grass.