Huge asteroid almost hit earth NASA didn’t detect it until a day later

originally posted by: Grenade
a reply to: beyondknowledge

You pretty much just agreed with everything i said.

Everything except this:

"However, if you're still in any doubt that it's possible to hear a meteor 'whoosh' you can also research electrophonics and VLF sounds."

You could very well hear a meteor overhead even when it's travelling at supersonic speeds.

earthsky.org...

www.livescience.com...

But you won’t hear it when it is there. It will be ether on the ground, burnt into dust, or back in space before the sound is heard.

a reply to: beyondknowledge

Read the articles i provided.

"But sometimes, meteors seem to make a sound at the same time that they are being seen. These meteors would be seen and heard simultaneously. Is this possible? Yes, according to astronomers. There are what astronomers call “electrophonic meteors.”

Basically, the explanation is that these meteors give off very low frequency (VLF) radio waves, which travel at the speed of light. Even though you can’t directly hear radio waves, these waves can cause physical objects on the Earth’s surface to vibrate. The radio waves cause a sound, which our ears might interpret as the sizzle of a meteor shooting by."

originally posted by: SeaWorthy

originally posted by: Kreeate
Historically there have been meteorites that hit the Earth that were kilometers wide (and long) with little to no effect.*

A meteorite that is mere meters wide (and long) and that passed the Earth at a distance of about 193 000 kilometers is hardly a threat.

*Hitting a city directly will of course have significant impact. No pun intended.

I always take the info and do my own research. Difficult now to trust anything or anyone right!

Your example proves my reply above. The sound from overhead is heard 5 seconds after the object passes. It is only .86 seconds from impact when that object is overhead. You will hear the sound from above a full 95 seconds before you hear it hit if you do hear it hit.

I have never said it won’t be heard. I am saying if you hear it, you are in no danger.

a reply to: beyondknowledge

Yes, it appears we are both agreeing with each other.

Your tone seems to suggest i'm wrong about something but i've yet to figure out what.

originally posted by: Kreeate
a reply to: Faeded

Wait... what? Engrish?!

"has a diameter of around 42 to 94 m, with a diameter or around 68 m"

So which is it?

For the record, I know that is directly from the article, which makes me wonder about many, many things.

if we lived in flat land you would be right but we live in the 3rd dimension so two ovals off set by 90 degrees to each other create a 3d object

Meteors that can be heard have nothing to do with sound initially.
The meteor creates a plasma which imparts electrical energy into the atmosphere as VLF waves.
The VLF is radio spectrum and travels at light speed.
If the observer is in the right place, and usually close to a large metal building made of sheet metal, then the VLF interacts with the metal in a modal relationship and makes it vibrate. That is where the sound comes from, and usually sounds like a high frequency whine or woosh.

The time delay is then computed as the distance from the metal structure and observer at 1200fps. The VLF travel distance delay from hitting the metal structure at light speed is negligible.

Sonic boom phenomena, which IS sound energy only, only occurs very low in the atmosphere as the meteor is transitioning from cosmic to terminal velocity and is usually accompanied with the explosion of the meteor as well.

a reply to: charlyv

Agreed, still they create a sound. I never specified the frequency of the waveform or the process by by which it was created, just thought people might find it an interesting phenomenon.

My cynicism makes me wonder if someone, somewhere, knew about this space rock but opted to not bring it up till after it'd passed. I could be wrong, but it wouldn't surprise me.

a reply to: Faeded

That's not very big as asteroids go. Now if it was 68 kilometers on a size now that would have been scary.

a reply to: Grenade

Yea, cool I get that. I used to study it as well year ago and found it fascinating. Hard to find an opportunity to drop that data

originally posted by: Kreeate
a reply to: Faeded

Wait... what? Engrish?!

"has a diameter of around 42 to 94 m, with a diameter or around 68 m"

So which is it?

For the record, I know that is directly from the article, which makes me wonder about many, many things.

I'm thinking you assume a meteor to be perfectly round. It is fairly apparent from the article this meteor was not round at all, but rather cylindrical in shape (ellipsoidal to be more precise). I think the word missing from the article was the word "average". It should have said...'has a diameter of around 42m to 94m, with an "average" diameter around 68m'

In any case, as meteors go, this one was definitely big enough to do some serious damage! The meteor which exploded over Tunguska, Russia in 1908 was less than half the size of this one, and it wiped out 800 square miles of forest! So, this badboy could have easily taken out a major city and all it's inhabitants.