Space junk?

[arthwollipot]

Here's a curious little story of a close call:

Unidentifed metal object falls through Gympie family's roof, narrowly missing baby bouncer

Quote:

A young family in Gympie has survived a bizarre ordeal after a heavy piece of metal crashed through the ceiling of their home overnight, narrowly missing their baby's bouncer.

Tenika Lawther said she was still in shock after the unidentified object rocketed through the roof and into their tiled floor just after seven o'clock last night.

She said her five-month-old daughter, Oceana Gardner, was sitting in the bouncer moments earlier and would have certainly been killed if she was struck by the metal that was around 3 centimetres in length.

"It was very scary," she said.

"If my daughter was sitting in her bouncer she would be dead."

There are plenty of pictures. Looks to me like something that could have been melted and resolidified at some point. It smashed straight through the roof and broke tiles as it hit, so it was moving at quite a clip.

Commence speculation!

[Michel H]

Yes, it may have been space junk, the energy of this little object was amazing. It doesn't look like an intact piece of equipment.

The police said it wasn't a matter for them, but a member of this family could have been seriously injured. They could contact the Australian Space Agency, or NASA.

It would perhaps be of some interest to know the weight of the metal object, I didn't find this information.

Wikipedia has a list of similar incidents:

Quote:

1979: portions of Skylab came down over Australia, and several pieces landed in the area around the Shire of Esperance, which fined NASA $400 for littering.[131]
...
2003: Columbia disaster, large parts of the spacecraft reached the ground and entire equipment systems remained intact.[137] ... In a rare case of property damage, a foot-long metal bracket smashed through the roof of a dentist office.[140]

(https://en.wikipedia.org/wiki/Space_debris#On_Earth)

An chemical analysis of the object could perhaps reveal its origin (kind of steel used and so on).

[theprestige]

Q. What's metal, travels at Mach 6, and strikes homes in Queensland Australia?

A. A Russian hypersonic missile aimed at houses in Ukraine.

[smartcooky]

Originally Posted by arthwollipot

Here's a curious little story of a close call:

Unidentifed metal object falls through Gympie family's roof, narrowly missing baby bouncer

There are plenty of pictures. Looks to me like something that could have been melted and resolidified at some point. It smashed straight through the roof and broke tiles as it hit, so it was moving at quite a clip.

Commence speculation!

Not seeing any pictures in the article you posted

ETA: OK, pictures show in Chrome, but not in Firefox.

That's not "space junk"... there is no indication of burning or scarring from re-entry.

[Skeptic Ginger]

Originally Posted by smartcooky

Not seeing any pictures in the article you posted

It's small, shiny silver colored.

Definitely not a meteorite but my vote would be space junk rather than something flying overhead due to the speed. Faster than terminal velocity?

I wonder if Oz has a All Sky Fireball Network like the US has?

Except I think that mostly catches night fireballs.

[arthwollipot]

I'd be surprised if they didn't send the object to some lab somewhere to be analysed.

Actually, I just realised what it looks like to me. You know those lead weights they attach when they balance your tyres? Lead would also be described as "heavy".

[smartcooky]

Originally Posted by Skeptic Ginger

It's small, shiny silver colored.

Definitely not a meteorite but my vote would be space junk rather than something flying overhead due to the speed. Faster than terminal velocity?

I wonder if Oz has a All Sky Fireball Network like the US has?

Except I think that mostly catches night fireballs.

For an object that size, whether it came from LEO, MEO or GEO or from a flight at, say 37,000ft would make no difference to its impact speed. This can be a hard concept to grasp. This video of a SpaceX booster landing might help .. watch the Stage 1 Telemetry on the bottom left. The video is cued to about 4 min at a point where the booster is still climbing to its maximum altitude, which can be seen by the velocity slowly reducing.

Now watch as the velocity slowly increases to about 8,000 km/h as the booster falls back toward the earth. That is too fast, and not slowing it down will cause severe structural damage to the engine bells, the octaweb and the grid fins.

So at that point, they fire the "entry burn" for about 20 seconds to being it down to about 5,700 km/h.

Now watch what happens when the entry burn terminates.... the booster doesn't speed up again, it continues to slow down because now, its travelling at over its terminal velocity so its being slowed down by atmospheric drag, and it comes right down to below 700 km/h before the landing burn begins.

https://youtu.be/G6PdvRAHcdE?t=240

ETA: The object in the Gympie photos looks and sounds (from its description) to be about the size and mass of a pool ball. The terminal velocity of a pool ball is about 170 km/h, and it would reach that velocity within about 600 metres of being dropped, so it doesn't matter whether its dropped from 3300 ft or 33,000 feet or from the very edge of space... 330,000 ft. By the time it reaches the ground, it will not be travelling faster than 170 kph.

[TalosMarr]

To go through a layer of tin, a layer of sheet rock, and then barely chip the floor tile pretty much any metal wouldn't really have to be going that fast. That chip and the sheet rock can be done with average throwing force and the tin isn't much better as far as fast moving bits of metal are concerned. The silver color could in fact be transfer from passing through the tin.

As far as terminal velocity goes, if it's something like steel, assuming a spheroid cross section before being smooshed, the terminal velocity of the object would be somewhere around 165 mph / 266 km/h assuming I estimated the values correctly, easily enough to punch through tin and sheet rock.

Terminal velocity calculated here with values pulled from google.

[arthwollipot]

Originally Posted by smartcooky

By the time it reaches the ground, it will not be travelling faster than 170 kph.

That's still quite a clip to be landing right next to someone's kid. It was a close call.

[Skeptic Ginger]

Originally Posted by smartcooky

For an object that size, whether it came from LEO, MEO or GEO or from a flight at, say 37,000ft would make no difference to its impact speed.

Depends. Some meteors enter the atmosphere and explode in which case all the destined-to-be meteorites fall at terminal velocity.

But some come in with a velocity that exceeds terminal velocity and they don't slow down like one would see were it in free-fall.

[smartcooky]

Originally Posted by Skeptic Ginger

Depends. Some meteors enter the atmosphere and explode in which case all the destined-to-be meteorites fall at terminal velocity.

But some come in with a velocity that exceeds terminal velocity and they don't slow down like one would see were it in free-fall.

No, it doesn't depend at all. We are talking about a piece a space junk here - an object that may have been IN ORBIT - that's the key fact you have to remember. An orbital object such as a piece of a satellite, falling from orbit to the earth, can never, ever enter the atmosphere at more than orbital velocity... 27,000 km per hour (7.5 km/sec). It also always enters at a shallow angle, so its travel distance over the curve of its trajectory covers thousands of kilometres as it slows down.

Meteors arrive into the Earths atmosphere from ANY angle, and their velocities range between 11 km/sec and 72 km/sec, that's a MINIMUM of 40,000 km/h and a maximum over over a quarter of a million kilometres per hour!!

Let me give you a comparison.

A 1m diameter spherical object, with a density of 3000 km/m³ falling from orbit, reaching a terminal velocity of 360 km/h, and impacting a porous rock surface on the earth at 90°, will create a crater with a rim-to-rim diameter of 10.5 metres, with an energy of 7.85 x 10⁶ Joules.

The same object entering the earth's atmosphere from deep space at 90°, with the average velocity of a meteor (about 41 km/sec) would hardly even slow down. There would be massive heating, and assuming that the object didn't lose any appreciable mass from that heating, and assuming it actually survived all the way to impact, would make a crater with a rim-to-rim diameter of 117 meters. with over 175,000 times more energy- 1.32 x 10¹² Joules.

[Armitage72]

Year ago, a scrap yard in a city near where I used to work was getting sued by their neighbors because they would put cars into their metal shredder without adequate precautions, there would be an explosion, and metal debris would be hurled across the neighborhood. One of the arguments in their defense was that their shredder exploded a lot less often than others.

[Trebuchet]

I see they're hoping insurance will cover it. I don't know how it is in Oz, but in the USA homeowners policies commonly exclude anything falling from the sky unless it's hail.

If I had found that first thing I'd be doing is checking with a magnet, followed by immersing in water to find the volume and weighing it to check the density. Color looks like aluminum.

[Skeptic Ginger]

Originally Posted by smartcooky

No, it doesn't depend at all. We are talking about a piece a space junk here - an object that may have been IN ORBIT - that's the key fact you have to remember. An orbital object such as a piece of a satellite, falling from orbit to the earth, can never, ever enter the atmosphere at more than orbital velocity... 27,000 km per hour (7.5 km/sec). It also always enters at a shallow angle, so its travel distance over the curve of its trajectory covers thousands of kilometres as it slows down.

Good point but there are 2 bits of evidence you aren't considering.

1) It had the force to go through the roof and IIRC to break some floor tiles. Do we know if said object at terminal velocity would have enough force to do that?

2) Isn't it possible what broke the space junk up and/or knocked the thing out of orbit could have imparted additional velocity to it?

Originally Posted by smartcooky

Meteors arrive into the Earths atmosphere from ANY angle, and their velocities range between 11 km/sec and 72 km/sec, that's a MINIMUM of 40,000 km/h and a maximum over over a quarter of a million kilometres per hour!!

Let me give you a comparison.

A 1m diameter spherical object, with a density of 3000 km/m³ falling from orbit, reaching a terminal velocity of 360 km/h, and impacting a porous rock surface on the earth at 90°, will create a crater with a rim-to-rim diameter of 10.5 metres, with an energy of 7.85 x 10⁶ Joules.

The same object entering the earth's atmosphere from deep space at 90°, with the average velocity of a meteor (about 41 km/sec) would hardly even slow down. There would be massive heating, and assuming that the object didn't lose any appreciable mass from that heating, and assuming it actually survived all the way to impact, would make a crater with a rim-to-rim diameter of 117 meters. with over 175,000 times more energy- 1.32 x 10¹² Joules.

Except for burning up on the way through the atmosphere, I'm not sure any of that applies but it's nice you know that stuff. Maybe you can comment on the force needed to crash through the roof.

We don't know the size of the object before it passed through the atmosphere.

[Skeptic Ginger]

Originally Posted by Trebuchet

I see they're hoping insurance will cover it. I don't know how it is in Oz, but in the USA homeowners policies commonly exclude anything falling from the sky unless it's hail.

If I had found that first thing I'd be doing is checking with a magnet, followed by immersing in water to find the volume and weighing it to check the density. Color looks like aluminum.

What would you be checking for? It clearly isn't a meteorite.

[Trebuchet]

I'd be curious as to what it's made of!

[RecoveringYuppy]

Originally Posted by Skeptic Ginger

1) It had the force to go through the roof and IIRC to break some floor tiles. Do we know if said object at terminal velocity would have enough force to do that?

Depends on what the roof is made of. There are plenty of roofs that could be penetrated by small objects falling at modest speeds.

Originally Posted by Skeptic Ginger

2) Isn't it possible what broke the space junk up and/or knocked the thing out of orbit could have imparted additional velocity to it?

At most, doubled it (with some caveats). But it's not really likely.

Originally Posted by Skeptic Ginger

What would you be checking for? It clearly isn't a meteorite.

How can you tell? Looks like just a hunk of metal to me. Meteorites can be that.

[Skeptic Ginger]

Originally Posted by RecoveringYuppy

...

How can you tell? Looks like just a hunk of metal to me. Meteorites can be that.

I can tell because I'm a meteorite hobbyist. I own a few and know what they do and don't look like. The metal in them is nickel-iron. None of them look like aluminum.

[RecoveringYuppy]

Originally Posted by Skeptic Ginger

I can tell because I'm a meteorite hobbyist. I own a few and know what they do and don't look like. The metal in them is nickel-iron. None of them look like aluminum.

OK, well that's good to know but you wouldn't know what all of them look like, right? Metallic aluminum meteorites are very rare (I actually only know of one) but they do exist.

But I also wonder if that is what an aluminum meteorite would like. It appears too shiny IMO. I would expect aluminum to look more like the bottom of a soda can due to oxidation. That looks even shinier and more silvery IMO than aluminum foil.

To me that looks like it's potentially a very pure nickel-iron sample. Especially since I don't know how the photo was taken.

[arthwollipot]

Originally Posted by Trebuchet

I see they're hoping insurance will cover it. I don't know how it is in Oz, but in the USA homeowners policies commonly exclude anything falling from the sky unless it's hail.

If I had found that first thing I'd be doing is checking with a magnet, followed by immersing in water to find the volume and weighing it to check the density. Color looks like aluminum.

Finding out what kind of metal it is would be a good first step. I expect that there are a few analytical techniques that could narrow down the source of the metal, and that might give us some ideas about where it came from.

I doubt we'll hear much of a followup in the media, though, and I'm not sure how I'd keep up with it. I expect that this mystery will remain unsolved on this forum.

[smartcooky]

Originally Posted by Skeptic Ginger

Good point but there are 2 bits of evidence you aren't considering.

I had already considered and dismissed them because I didn't consider them worth mentioning, but ...

Originally Posted by Skeptic Ginger

1) It had the force to go through the roof and IIRC to break some floor tiles. Do we know if said object at terminal velocity would have enough force to do that?

Since it has to be at its terminal velocity or less, and it did punch through the roof, then the answer MUST be yes. If it is space junk, it cannot have exceeded its terminal velocity by the time it reached ground level. Nothing used by humans in space has sufficient mass and density to still be accelerating at impact.

Originally Posted by Skeptic Ginger

2) Isn't it possible what broke the space junk up and/or knocked the thing out of orbit could have imparted additional velocity to it?

No, its not, not even close.

Even if you are in orbit, with a gun with the highest muzzle velocity you can find, and fire a bullet straight down, it is doubtful this will even impart enough energy to make the bullet re-enter, let alone do so with enough energy to still be exceeding its terminal velocity in impact.

If an object in orbit (and therefore travelling at 27,000 km/h) is hit from behind by another object (which of course cannot itself be in orbit), that would cause the impacted object to speed up, which would cause it to be pushed into a higher orbit, not to re-enter.

To leave orbit and return to Eearth, you have to slow down, not speed up!

Originally Posted by Skeptic Ginger

Except for burning up on the way through the atmosphere

The object in question is melted but otherwise shows no sign of "burning up on the way through the atmosphere". Re-entered space junk shows marks such as pitting and scorching. This object show no such marks

Originally Posted by Skeptic Ginger

I'm not sure any of that applies but it's nice you know that stuff.

You'll learn a lot more by trying to understand what I have said and why I am saying it, rather then by being patronizing.

Originally Posted by Skeptic Ginger

Maybe you can comment on the force needed to crash through the roof.

Lets use a simple object, a ball bearing the size of a golf ball. Here's the details

Steel ball bearing: Diameter 4cm,
Density: 8000 kg/m³
Drop height: 2,500 feet
Terminal velocity (Vt): 413 km/h (114 m/s)
Time to Vt = 12 sec
Altitude of Vt: 300 feet
Target: Concrete roofing tile material - 78kg/m3
Damage to target: A crater with a rim-to-rim diameter of 3.41 meters.
Energy: 1.88 x 10³ Joules

NOTE: The crater size assumes the target is ALL concrete roofing tile material, e.g. a 1m thick 10m x 10m single roofing tile. The reality is that roofing tiles are only a couple of cm thick, so the ball bearing, will reach terminal velocity about 12 seconds after it is dropped, at an altitude of about 300. It does not matter how much higher it is dropped from, whether is, 30,000 feet or 330,000 feet (the edge of space) IT WILL NOT BE TRAVELLING FASTER THAN 413 km/h at impact!

So, to answer your question, yes, I can comment on the "the force needed to crash through the roof." Dropped from even as little as 2500 feet, the 4cm steel bearing it would have punched straight though that roof and the ceiling (as described) without stopping, and would have struck the floor with sufficient force to crack them.

Originally Posted by Skeptic Ginger

We don't know the size of the object before it passed through the atmosphere.

True, but not relevant

Now, if you still don't get it, I give up. I'm not doing any more calculations for you. Here are references you need, you can do the calculations yourself

https://www.eaps.purdue.edu/impactcrater/crater_c.html

https://www.omnicalculator.com/physics/free-fall

https://www.gigacalculator.com/calcu...calculator.php

https://goodcalculators.com/sphere-calculator/

https://www.precisionballs.com/Ball_Bearing_Steel.php

http://hyperphysics.phy-astr.gsu.edu...irfri2.html#c3

[smartcooky]

I am almost 100% certain that this is NOT man made space junk. Its appearance doesn't match any of the descriptors that I know of.

If it is a meteorite, it is an exceedingly rare one.

[RecoveringYuppy]

Originally Posted by arthwollipot

I doubt we'll hear much of a followup in the media, though, and I'm not sure how I'd keep up with it. I expect that this mystery will remain unsolved on this forum.

You're closer to them than I am. Could you just run over and tell them about the International Meteor Organization? You could easily carry the minor equipment needed to do Trebuchet's density test.

[Skeptic Ginger]

Originally Posted by RecoveringYuppy

OK, well that's good to know but you wouldn't know what all of them look like, right? Metallic aluminum meteorites are very rare (I actually only know of one) but they do exist.

But I also wonder if that is what an aluminum meteorite would like. It appears too shiny IMO. I would expect aluminum to look more like the bottom of a soda can due to oxidation. That looks even shinier and more silvery IMO than aluminum foil.

To me that looks like it's potentially a very pure nickel-iron sample. Especially since I don't know how the photo was taken.

First, yes I do have a general idea of what they all look like.

Second, if you weren't sure, look at one image of it, not the least bit natural.

And third, I found a link to one meteorite with aluminum in it and it's not an aluminum looking rock.

Caltech: Three New Minerals Discovered in a Unique Meteorite

Quote:

The newly dubbed stolperite—so named in recognition of Stolper's "many fundamental contributions to petrology and meteorite research, and support for natural quasicrystal research," Ma says—is an alloy of metallic aluminum and copper (chemical formula: AlCu). Structurally, stolperite is arranged in a cubic form, with each copper atom at the center of a cube with aluminum atoms at all eight corners (and, likewise, each aluminum atom sits at the center of a cube of eight copper atoms).

"Normally we don't observe such aluminum-rich metal in space rocks because the aluminum would have reacted to form aluminum oxide," Ma says. This means that the likelihood of finding other stolperite samples is low. In fact, the Khatyrka meteorite is the only meteorite ever found that contains metallic aluminum; the meteorite fragment hosting the trio of new minerals is now in the holdings of the Smithsonian Institution National Museum of Natural History, which maintains a catalog of more than 600,000 specimens.

No way is there a meteorite that looks like aluminum. But go ahead, surprise me with a link. I love learning new things.

[Skeptic Ginger]

Originally Posted by smartcooky

You'll learn a lot more by trying to understand what I have said and why I am saying it, rather then by being patronizing.

[deleted what I would have said if it weren't for board rules] If anyone is being patronizing it's you. Sorry you went to all that trouble but I don't need a lesson in the physics of falling objects.

I have not changed my position that a meteoroid could hit space debris and impart velocity.

The consequences of collisions between spacecraft and a micrometeoroid or a piece of space debris can be catastrophic. Collisions take place at hyper-velocities of about 10 km/s with dissipation of huge kinetic energies for very small particles.

However, if more than terminal velocity wasn't necessary to puncture the roof and break floor tiles, (I do believe you on that), it's a moot point not worth any further discussion.

[Skeptic Ginger]

Originally Posted by smartcooky

I am almost 100% certain that this is NOT man made space junk. Its appearance doesn't match any of the descriptors that I know of.

If it is a meteorite, it is an exceedingly rare one.

It's not a meteorite, even a rare one for a dozen reasons.

If it's not space debris then are you suggesting it fell off an aircraft of some kind?

Wouldn't some damage like that have been an issue with the craft?

[arthwollipot]

Originally Posted by RecoveringYuppy

You're closer to them than I am. Could you just run over and tell them about the International Meteor Organization? You could easily carry the minor equipment needed to do Trebuchet's density test.

According to Google Maps, it will take me 257 hours to get to Gympie by foot. I'd better get a bike so that I can do it in only 65 hours. Be right back.

[smartcooky]

Originally Posted by Skeptic Ginger

[deleted what I would have said if it weren't for board rules] If anyone is being patronizing it's you.

"but it's nice you know that stuff" is about as patronizing as it gets!!.

Originally Posted by Skeptic Ginger

Sorry you went to all that trouble but I don't need a lesson in the physics of falling objects.

Well yes, yes you do, because you clearly do not understand physics of falling objects. How do I know this - because the things you have been saying about falling objects are clearly, mathematically, scientifically and demonstrably WRONG!

Originally Posted by Skeptic Ginger

I have not changed my position that a meteoroid could hit space debris and impart velocity.

It could, but if it caused the space debris to increase its velocity, IT WOULD NOT RE_ENTER THE EARTH'S ATMOSPHERE.... PERIOD!!! This is Orbital Mechanics 101.

Your collision would be the second of two cases where Δv is applied to an object in orbit

1. When Δv is applied over a time much longer than the original orbital period (very low thrust applied continuously over several orbits) this results in the object going to a higher and slower (but still circular orbit)

2. When Δv is applied over a time much shorter than the original orbital period (high thrust applied for a short time, or as in your case, a collision) then the orbit of the object becomes more elliptical with the apogee being raised higher than the original orbit and the perigee remaining the same as the original orbit. This is the basis of what is known as a Hohmann transfer, and is commonly used when an object in LEO is being boosted to GEO.

...and I don't blame you for not understanding this. Orbital Mechanics is one of the most counter-intuitive things in space science. Not only do objects sometimes do the opposite of what your intuition tells you they should do, they some times do things your brain didn't even think of.

To be clear though, nothing....NOTHING can happen to a human made object in orbit that would make that object de-orbit, fall to Earth, and impact the Earth at a velocity greater than its terminal velocity. There is nothing, no material or object used in any space program with enough density packed into a small enough size, to not reach terminal velocity in Earths atmosphere.

Originally Posted by Skeptic Ginger

The consequences of collisions between spacecraft and a micrometeoroid or a piece of space debris can be catastrophic. Collisions take place at hyper-velocities of about 10 km/s with dissipation of huge kinetic energies for very small particles.

Interesting, but completely irrelevant to what is being discussed here. The hyper-velocities being talked about there are those of the meteoroid NOT the space debris.

[smartcooky]

Originally Posted by Skeptic Ginger

If it's not space debris then are you suggesting it fell off an aircraft of some kind?

This is certainly more likely than space junk

https://www.baltimoresun.com/news/bs...029-story.html

Like cars losing hub caps and mufflers on the highways, airplanes periodically shed objects such as aluminum skins, access panels, fuselage doors, red hot turbine blades, frozen sewage, and even whole engines.

Hurtling toward Earth at hundreds of miles per hour, such fall out has punched gaping holes in roofs, crushed cars into pancakes, plunged into crowded swimming pools, smashed school desks, showered people with human waste, sent glass shards shooting through living rooms and set houses on fire.

https://interestingengineering.com/t...an-you-thought

Originally Posted by Skeptic Ginger

Wouldn't some damage like that have been an issue with the craft?

Not necessarily.

[Skeptic Ginger]

Originally Posted by smartcooky

[snipped waste of time stuff]

I don't understand why you think my compliments are condescending. They were not intended to be so.

Oh well.

[smartcooky]

Originally Posted by Skeptic Ginger

I don't understand why you think my compliments are condescending. They were not intended to be so.

Oh well.

Your thinking that my directly addressing your claims and trying to answer your ******* questions was "waste of time stuff" tells me everything I need to know.

For me, this has been like dealing with an ill-behaved five year old!

[Jack by the hedge]

Before the thread reaches terminal velocity, I'd like to opine that the object looks like a flattened lump of soft metal. It's only 3cm across when flattened so maybe only enough to make a 15mm ball. Looks like aluminium but could be lead.

I might consider a source as down-to-earth as some local idiot taking pot shots at birds with a sling rather than look to space.

[MBDK]

Originally Posted by smartcooky

if it caused the space debris to increase its velocity, IT WOULD NOT RE_ENTER THE EARTH'S ATMOSPHERE.... PERIOD!!! This is Orbital Mechanics 101.

First of all, I thank you for the information provided, and absolutely concur that the object is not man-made space debris. However, to insert myself as devil's advocate, were an orbiting bit of such debris to be impacted by a faster-than-terminal-velocity object of significantly greater mass, I am certain there is an angle of approach that, should the collision be more or less elastic, could theoretically redirect the debris in a faster-than-terminal-velocity and direction that travels steeply into Earth's atmosphere.

That said, I am even more certain that any such collision would need to be nearly head-on, and wouldn't be remotely elastic, with the most likely result being the debris ending up as a newly amalgamated hitchhiker for the impactor.

[smartcooky]

Originally Posted by MBDK

First of all, I thank you for the information provided, and absolutely concur that the object is not man-made space debris. However, to insert myself as devil's advocate, were an orbiting bit of such debris to be impacted by a faster-than-terminal-velocity object of significantly greater mass, I am certain there is an angle of approach that, should the collision be more or less elastic, could theoretically redirect the debris in a faster-than-terminal-velocity and direction that travels steeply into Earth's atmosphere.

That said, I am even more certain that any such collision would need to be nearly head-on, and wouldn't be remotely elastic, with the most likely result being the debris ending up as a newly amalgamated hitchhiker for the impactor.

An orbiting piece of space junk the size of a golf ball, hit by an incoming meteor 100m across travelling at 40 km/sec?

OK, the piece of space junk would exceed its terminal velocity by virtue of it being embedded in the meteorite. But yeah, that's a bit like claiming your cat can do 850 km/h because it was once transported in a pet cage in the cargo hold of an airliner

[Darat]

Originally Posted by arthwollipot

According to Google Maps, it will take me 257 hours to get to Gympie by foot. I'd better get a bike so that I can do it in only 65 hours. Be right back.

That's next door to you on Australian scales!

[MBDK]

Originally Posted by smartcooky

An orbiting piece of space junk the size of a golf ball, hit by an incoming meteor 100m across travelling at 40 km/sec?

OK, the piece of space junk would exceed its terminal velocity by virtue of it being embedded in the meteorite. But yeah, that's a bit like claiming your cat can do 850 km/h because it was once transported in a pet cage in the cargo hold of an airliner

My cat says it's legit if he's the pilot. Sometimes, I think my cat may be smarter than me...

[JayUtah]

It's far more likely to be a part from an airplane.

[Trebuchet]

Originally Posted by JayUtah

It's far more likely to be a part from an airplane.

it looks melted to me. Parts falling off airplanes would retain their shape. I'm thinking a piece of a spacecraft.

[theprestige]

Originally Posted by Trebuchet

it looks melted to me. Parts falling off airplanes would retain their shape. I'm thinking a piece of a spacecraft.

Doesn't look melted to me. Just badly scraped. I'm liking the tire-balancing metal weight came loose from a passing car hypothesis.

[RecoveringYuppy]

What accounts for the "smoke" reported? Dust from roof?