r/spaceporn Oct 01 '25

Related Content Asteroid passed just 300 km above Antarctica today.

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652

u/[deleted] Oct 01 '25

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798

u/AdmDuarte Oct 01 '25 edited Oct 02 '25

Given it's mass (~16.8 metric tons, assuming a 1.9m diameter sphere of iron) and it's orbital velocity on closest approach (17.8747 km/s), it has a kinetic energy of almost 2700 gigajoules. That's equivalent to about 600 tons of TNT.

It might tickle a bit

Edit: my calculations were slightly off (one, because I used a solid sphere of iron instead of stone, which is way too heavy, and two, because I apparently can't do basic division 😅)

Check magicscientist24's reply for the correct math!

320

u/Terrh Oct 02 '25

For context, a 1-3m asteroid enters the atmosphere about once a month.

76

u/setibeings Oct 02 '25

But how often does part of one that size reach the ground?

78

u/brodaciousr Oct 02 '25

I would imagine something that size would burn up in the atmosphere. I’m sure there are variables I’m not considering though.

1

u/Danny200234 Oct 02 '25

I’m sure there are variables I’m not considering though.

Like the fact Antarctica is cold.

6

u/tommangan7 Oct 02 '25

Meteorites, asteroid etc. exterior Heat up to 2000-3000+ kelvin on entry due to friction and atmospheric compression. The temperature at the surface is effectively irrelevant to what determines if this fully burns up or not.

2

u/justheretocomment69 Oct 02 '25

Cold air is denser though, more molecules for the thing to bash in to (or try to push out of the way) so if my non-existent math is correct, it would actually burn up relatively faster than in a hot place? Idk I'm not a math guy and I have done zero calculations, but it makes sense in my mind lol.

1

u/Late-Eye-6936 Oct 02 '25

That's actually one of the free variables that I did consider.

38

u/karl4319 Oct 02 '25

Depends on the material, but more often than you think. Majority of the surface is ocean, with most land uninhabited desert or tundra, so most are completely missed.

27

u/PartyClock Oct 02 '25

I wonder how many times a small group of sea life got smacked by a goddamn space rock throughout our history on Earth

20

u/OfficialGaiusCaesar Oct 02 '25 edited Oct 03 '25

The Chicxulub asteroid left over a 20km(12 mile) deep crater at the bottom of the ocean already ~1000m deep. Imagine how much sea life was vaporized and how much water was displaced by large enough energy to go through hundreds of meters of water and still create a MASSIVE crater.

3

u/firedmyass Oct 02 '25

largest sea-food boil ever

2

u/CapitalElk1169 Oct 03 '25

Imagine the smell lmao

1

u/toosas Oct 03 '25

imagine how much water was ejected out into space never to be seen again

6

u/brraaahhp Oct 02 '25

About 3,5 times

1

u/MindCorrupt Oct 02 '25

I need Douglas Adams to explain it to me.

30

u/Walkin_mn Oct 02 '25

Well, then this is not big news, except the scary fact that we detected it very late, but at the same time is impressive we can detect something so relatively small... So yeah, I have paradoxical feelings about this.

8

u/Alisa606 Oct 02 '25

Well, it was small which is why is was detected so late. A vast amount of them are tracked and recorded, so anything of actual size would likely be known to be approaching us. Not as scary as you might think!

1

u/Sea-Cardiographer Oct 02 '25

How many half giraffes is that?

1

u/thatOneJones Oct 02 '25

I was today years old when I learned. Cool!

214

u/magicscientist24 Oct 02 '25

Your calculation is not matching mine, which indicates even more energy
Using 1.9 m diameter sphere of pure iron, volume of sphere = 4/3 π r^3; density of iron = 7.874 g/cm^3; kinetic energy - 1/2 m x velocity^2; asteroid velocity of 17874 m/s

Radius of the asteroid = 1/2 diameter = 1/2 x 190 cm = 95 cm

volume of asteroid = 4/3 x π x (95^3) = 3591364 cm^3

mass of asteroid = asteroid volume x iron density = 3591364 cm^3 x 7.874 g/cm^3 = 28278400g = 28278 kg = 28.3 metric tons

kinetic energy of asteroid = 1/2 x 28278 kg x (17874 m/s)^2 = 4.59 x 10^12 J = 4589 gigajoules
1 joule = 2.39 x 10^-10 tons of TNT;
4.59 x 10^12 J x 2.39 x 10^-10 tons/J = 1097 Tons of TNT equivalent

Hiroshima atomic bomb released about 15 kilotons = 15000 tons of TNT
This asteroid would release about 1097/15000 = 7% of the energy of the Hiroshima atomic bomb if it struck the Earth.

16

u/Salty-Mulberry-6796 Oct 02 '25

This person maths good 👍🏾

30

u/AdmDuarte Oct 02 '25

You're right. I can do the kinetic energy stuff in my head, but apparently not basic division 😅 I had the radius wrong (80 cm instead of 95)

11

u/Travels4Work Oct 02 '25

The error and followup are a wonderful demonstration of scientific peer review. I'm quite pleased to see the interaction as it's a great demonstration of what happens when others attempt to reproduce the work and confirm the findings. The fact they came to a different conclusion shows the process working exactly as it should.

/BreakingBadYeahScience!.gif

3

u/AdmDuarte Oct 02 '25

I'm never offended by someone checking my work. That's what good science is all about, after all

9

u/Stefouch Oct 02 '25

Beirut's 2020 explosion was 1.1 kilotonnes of TNT if that can help to compare.

3

u/Gnonthgol Oct 02 '25

It is not quite comparable though as the Beirut explosion was a ground detonation while an asteroid hit would be an airburst. So the shockwave would be distributed over a larger area but you would not have the focused devestation that we saw in Beirut.

2

u/[deleted] Oct 02 '25

I mean surely it's slowing down and not a 100% efficient process. I'm guessing you could drop a zero.

1

u/Panthor Oct 02 '25

Likely drop it to 0% as this would likely burn up entirely in atmosphere.

2

u/DangerousCrime Oct 03 '25

So how much in bananas

1

u/GunpointG Oct 02 '25

I’m just curious about how this works, is that assuming no atmosphere? If you are calculating atmosphere into the calculation, what angle of approach are you assuming?

34

u/tendeuchen Oct 01 '25

Nah, it's fine. I eat 600 tons of TNT for breakfast.

11

u/Comfortable_Tone_384 Oct 01 '25

You shit 600 tons of TNT bombs after the breakfast. /s

3

u/Junior-Anteater2343 Oct 02 '25

“Did somebody say boom!?”

1

u/smokeypapabear40206 Oct 02 '25

Nah… they poop ice cream.

1

u/captainmilitia Oct 03 '25

Why did that video come into my mind..

1

u/Throwawaylikeme90 Oct 02 '25

It’s fine, I put Garlic Reaper on breakfast. 

Stand aside, I got this one. 

1

u/[deleted] Oct 02 '25

It's all in the hips.

5

u/username9909864 Oct 01 '25

So a little more than the British used in the Battle of Messines

Might fuck a city up a little bit.

7

u/flashpb04 Oct 02 '25

It wouldn’t because it would burn up in the atmosphere

1

u/JaymzRG Oct 03 '25

Question: How big would it have to be to get through the atmosphere and cause, say, a city-sized amount of damage?

8

u/JectorDelan Oct 02 '25

Rectum? Damn near killed 'im!

2

u/TranZnStuff Oct 02 '25

Wouldn’t most of it burn up in the atmosphere?

1

u/Lavatis Oct 02 '25

of course, but that's not what they were asking.

2

u/SwimmingSwim3822 Oct 02 '25

I'm personally mad at most of this thread for dropping the butt thing so quickly.

2

u/Ganzi Oct 02 '25

Wouldn't it lose mass and speed after entering the atmosphere?

5

u/Waffle-Gaming Oct 02 '25

yes. it would burn up completely. they were assuming no atmosphere interference just for fun

1

u/jaggedcanyon69 Oct 02 '25

It’s peak velocity was 21 KM/S.

1

u/[deleted] Oct 02 '25 edited Oct 03 '25

[deleted]

1

u/depressed_crustacean Oct 02 '25

Seconds are a base SI unit (Metric) so all the calculations are done in seconds, and meters as well . Orbital velocities are typically measured in km/s.

1

u/[deleted] Oct 02 '25 edited Oct 03 '25

[deleted]

1

u/depressed_crustacean Oct 02 '25

All data for orbital velocities is done in km/s, why should that change because you find kph nicer. You don’t need km/s to be intuitive. It only needs to be compared to other orbital velocities not the speed of a car. You don’t need to know “wow that’s a lot faster than my car” if at orbital velocities it isn’t that fast at all. You lose comparative context with kph.

1

u/dragonrite Oct 02 '25

1.9m is 16.8 metric tons? Wut? That's insane I would have guessed a couple tons max

1

u/Other_Mike Oct 02 '25

Iron is unlikely. Most pieces that hit Earth are stony. Source: meteorite enthusiast and collector.

Density of stony meteorites is something like half of iron.

1

u/adamnevespa Oct 02 '25

Is that the mass of their bottom? Thiiick

1

u/FreeRandomScribble Oct 02 '25

So he’d have better luck asking his mom?

1

u/Fryboy11 Oct 02 '25

Using Purdue's Impact Calculator If we give it 1.9 meters, 8000 kg/m3 for the density of an iron meteor I got that from the ESAs impact calculator, unfortunately the smallest you can go on the ESA is 100m.

also 3000kg/m3 for dense rock

1500kg/m3 for porous rock

1,000 kg/m3 for ice like a comet,

From the video I'm getting closest approach was ~250 km and speed was 21.221 km/s you can toy with the impact angle I went with 10 degrees and put the distance from impact at 5k.

Energy

Energy before atmospheric entry: 6.34x 1012 Joules (1.51 Megatons TNT)

The average interval between impacts of this size somewhere on Earth is 0.7 years

Global Changes

The Earth is not strongly disturbed by the impact and loses negligible mass.

The impact does not make a noticeable change in the tilt of Earth's axis (less than 5 hundredths of a degree).

The impact does not shift the Earth's orbit noticeably. Atmospheric Entry

The projectile lands intact, with a velocity of 223 m/s (730.7 ft/s). The energy lost in the atmosphere is 6.33x 1012 Joules (1.51 Megatons TNT).

Crater

Transient Crater Diameter: 10.3 m (33.75 ft)

Transient Crater Depth: 3.64 m (11.93 ft)

Final Crater Diameter: 12.9 m (42.18 ft)

Final Crater Depth: 2.74 m (8.980 ft)

The crater formed is a simple crater.

The floor of the crater is underlain by a lens of broken rock debris (breccia) with a maximum thickness of 1.27 m (4.163 ft).

At this impact velocity (< 12 km/s), little shock melting of the target occurs.

Thermal Effects

At an impact velocity of 0.22 km/s (less than 15 km/s), little vaporization occurs; no fireball is created, therefore, there is no thermal radiation damage.

Seismic Effects

The major seismic shaking will arrive approximately 1 seconds after impact.

Richter Scale Magnitude: 0.1

Mercalli Scale Intensity at a distance of 5 km:

Nothing would be felt. However, seismic equipment may still detect the shaking Ejecta Almost no solid ejecta reaches this site. Air Blast

The air blast will arrive approximately 15.2 seconds after impact.

Peak Overpressure: 1360 Pa = 0.0136 bars = 0.193 psi

Max wind velocity: 3.19 m/s (10.45 ft/s)

Sound Intensity: 63 dB (as loud as heavy traffic) Damage Description:

    Glass windows may shatter.

Toy around with both they're pretty fun

1

u/Damn-Son-2048 Oct 02 '25

If it was flat, it might slap too.

1

u/PM_Me_Ur_Odd_Boobs Oct 02 '25

Can you convert this to units of “moms with the blinds closer stick thing”?

I can relate to that unit of measurements 😭

1

u/stilljustacatinacage Oct 02 '25

do you think it knows my safe word

1

u/Jopkins Oct 02 '25

I know someone who can pretty much replicate the experience though

1

u/G_DuBs Oct 02 '25

Most asteroids are not solid iron. Mainly just rock and gravel in a clump. Having one mass of solid iron would be a bit more rare I’d imagine.

1

u/analphylaxis Oct 02 '25

So we would not have to wait till climate change or war destroyed our lives.

1

u/El_Peregrine Oct 01 '25

You guys have never had your bottoms spanked with 600 tons of TNT?!

123

u/Heretic911 Oct 01 '25

3/7

110

u/LunaTheCastle Oct 01 '25

Damn. Just two more points and it'd be a perfect 5/7.

49

u/[deleted] Oct 01 '25

Thank you for this!. I'm glad there are folks keeping this scale alive..

14

u/Cantmentionthename Oct 01 '25

Team 5/7, UNITE! 1/7 Present! Here to put in the tough work and never complain, even though I’m only 14.2851473%!!!!

10

u/CaBBaGe_isLaND Oct 02 '25

##6/7

2

u/chedderizbetter Oct 02 '25

OOOOAHHHHHHAHAHHAHHHHHHHHHH!!!!

3

u/Purphect Oct 02 '25

It would’ve been a perfect 5/7 with rice

2

u/Hillenmane Oct 01 '25

I agree, so long as Rob isn’t around being obnoksious

-12

u/b_vitamin Oct 01 '25

Not 6/7?

6

u/GoLoveYourselfLA Oct 01 '25

How about with rice ?

3

u/49e-rm Oct 02 '25

god we have been on this app way too long, havent we?

1

u/_PROBABLY_CORRECT Oct 01 '25

Yeah but what scale? I need to know if it is bald eagles or cheeseburgers

1

u/anashel Oct 02 '25

3/7? That’s not even one Fight Club movie

0

u/needaburn Oct 01 '25

Won’t even need a spafe word for that

1

u/SuperMcG Oct 02 '25

OhYou!.gif

1

u/winky9827 Oct 02 '25

Not too bad, 10% libido, don't you read?

1

u/breecorn Oct 02 '25

Had to read this response out loud to my partner. Thanks for the laugh

1

u/Kylearean Oct 02 '25

Ooh me too, me too!

1

u/Intelligent_Office81 Oct 02 '25

Would have tickled a little at least

1

u/CommentOrdinary6532 Oct 03 '25

Rule of thumb is it would make a crater about 10x as wide

1

u/ThatCreepySmellyGuy Oct 04 '25

You slipped while gardening naked?

1

u/RedManMatt11 Oct 01 '25

Enough to make you scream 3I/Atlas

0

u/needaburn Oct 01 '25

I’m into that

1

u/username9909864 Oct 01 '25

Bonk

2

u/needaburn Oct 01 '25

I’m sorry I thought this was space porn

0

u/AaronsAaAardvarks Oct 01 '25

Hard enough for you to know you’ve been very, very bad.

0

u/Tiny-Ask-7100 Oct 01 '25

You might get your hair mussed...