Fireball and flash in the sky alarms Utahns

Originally posted by AirWitch
Even historically there seems no precedence for this (although our population and technology certainly make observation more likely).

But, are we entering an area of space that is dirtier than what we’ve previously been in? At this rate, we might just get hit by something larger in the next few years ... (2012 anyone?)

Just to address this part of your post, which I neglected to do before, and also to expand on what was said in the other thread I linked to in my previous relpy above:

You said it right there, but it's not just that we are better at detecting/photographing them...

As I have said many times in the past on this forum, if you come to this subject with out much prior knowledge of it, it can seem that there are more events like this, but what you should keep in mind are that a number of factors will have a heavy influence on your perception.

For an individual, seeing an event like this is usually a lucky once in a lifetime experience. Few get to see two, since events like this are random although they do happen fairly frequently somewhere in the world. Of course the world is a big place, and the vast majority of it's surface is sea or uninhabited. Most of our population is highly concentrated into small areas, and the rest is sparsely or even virtually uninhabited. Also, daylight probably hides a large proportion of events.

They were always occurring, but because there were not many cameras (CCTV, digi-cams, camera networks devoted to looking 24/7 for these kinds of events, US DoD satellites, etc...), we did not know just how frequent they were. Researchers themselves are only just becomming aware of the frequency of small sized objects like this, and that is partly due to better communications and news gathering.

Previously, if an event like this was observed in a locality, the local news would pick up on it (if that - sometimes it might just be written off as a "ufo sighting" since many people are unaware what a bright meteor/fireball can look like, and how confusing it can sometimes be for the uninitiated) and that was it. The mainstream news would never pick up on it.

Today, thanks partly to massive increase in fireballs captured on camera, and many competitive news networks hungry for ratings, exciting footage of a fireball will often result in it making the mainstream news.

For every one that does, there must be at least ten or twenty that are observed/reported that don't make the mainstream news, but those of us who follow these events hear about, and probably again at least as many that are not reported at all due to the reasons I mentioned above.

I don't think that there is any evidence to suggest that these type of events are becoming more frequent. I do think we are still trying to establish a "baseline" for the frequency of these types of events (something that might have been done by now if the US DoD was more willing to share data with scientists, but it's a prickly issue with world security potentially at stake!).

I also think the public needs some general education about these type of events to try and dispel many of the myths that are associated with them. My personal experience has been that even many experienced astronomers and sky watchers who do not specialize in this field are not aware of a whole host of aspects concerning meteors, so you are not alone in that respect.


After just having written all of that I read the link you posted. Nice find by the way - bookmarking the link for future reference!

[edit on 18-11-2009 by C.H.U.D.]

reply to post by NotTooHappy

Ditto here but on the south side of the house.
Thats exactly what it looked like here also.
It looked like huge spotlights shining on the house!
Lit everything up outside for a sec.
Extremely bright white light.
Weirdest thing I've seen in quite awhile....

Originally posted by C.H.U.D.
You should take the time to look at some examples of trains left by meteors before proclaiming that it can't be one.

I did that immediately after posting, because I realized that I didn't know what I was talking about and had probably just made a fool of myself. Note to self: next time look it up *before* posting, especially at ATS. :-)

However, the scientists at the authoritative website Spaceweather.com STILL say that a meteor train does not last for six hours, as this one apparently did. Which makes your statement quite accurate:

Originally posted by C.H.U.D.
it's near impossible that it was due to the same fireball though

Therefore my next question is, how long do *missile* contrails last?

Originally posted by OuttaHere
Therefore my next question is, how long do *missile* contrails last?

That's a little bit like asking how long a piece of string is...

Initially they would deform quite rapidly, much like a meteor train, but they can also hang around and trigger NLC (noctilucent cloud) displays, it's thought. The same is also suspected to be true for some larger meteors. That's why this case is a little baffling for everyone.

Personally, I would lay odds on it being a second fireball. However, it seems unlikely that an event causing a trail of that magnitude would not be heard or seen by at least someone. IMHO there is still enough structure in that trail that it can not have been produced less than 30 minutes (60 tops) before Don Brown snapped it.

Have a look at some of the cases here: aquarid.physics.uwo.ca...

I think the Tagish Lake Meteorite had quite a long and lingering trail that resembled this one, if memory serves.

Here's some new footage of the event from a police cruiser's dash cam in Grand Junction, Colorado.




Slightly better quality here, but I don't know how to embed it here.
vp.mgnetwork.net...

Yeah i remember seeing the video for this impact?? I would think that there would be at least a few calls in about it

I have never seen a streak through the skies quite like that.

Nice post

The exact same thing happened in South Africa... tuesday night... weird??

www.news24.com...

Originally posted by 5 oClock
The sonic boom wasn't felt till about 5 min. after the flash. Wow! I understand that makes it pretty far awy but to be that bright to shut off the photocells to streetlights, I think that would also make it very large.

www.spaceweather.com...

Well in 5 minutes the sound would of travelled about 3,700 miles!!! - add to that the fact that it must of been in the atmosphere for the boom to be heard then hell yhea I'd say that was a biggie! - more likely though the 5 minutes is exaggerated - peoples perception of time changes dramatically when something exiting happens - it is notoriously unreliable for things like accidents and crimes, don't see why an exploding fire ball would be any different...

reply to post by Now_Then


Where do you get 3700 miles in 5 minutes? The sound would have to be traveling at 44400 miles per hour which is impossible. The speed of sound is roughly 700 mph at sea level in standard atmospheric conditions. The speed of sound is even slower as altitude increases. I'd check your math.

So, let's say that it was 700 mph. That means the sound is traveling about 11 miles a minute. So if he heard the sonic boom 5 minutes later that would put him about 60 miles from the explosion. Make sense?

[edit on 26-11-2009 by av8r007]

reply to post by av8r007


dammit your right - I was typing that while doing 3 other things at once right after waking up! - That's 5 x 740 = 3,700 That's 5 hours not 5 mins!!!!

To quote Mos... 'Egg and my face are in alignment'

Originally posted by 5 oClock
Wow! I understand that makes it pretty far awy but to be that bright to shut off the photocells to streetlights, I think that would also make it very large.

Not necessarily that "large", in terms of size anyway. Certainly bright though!

Bright meteors can exceed the brightness of the Sun, and I think there is a good chance that this one did, at least briefly! It's hardly surprising that the photo-sensors on street-lights would have been tripped.

In case anyone is wondering where all that brightness comes from, it's due to the speed of the object. The faster an object is going, the more kinetic energy it has. Asteroids are usually traveling at around 30 km/s relative to us when they hit, although I think this one was a bit more.

30 km/s is 67104 miles per hour, or 32 times faster than a high velocity rifle bullet (around 3000 fps). Something the size/weight of a standard can of coke, traveling at that speed, would probably have the kinetic energy of a truck going at 100 mph! (plucking figures out of the air here, but if someone wants to do the math...)

An asteroid like the one in question was probably a couple of meters across, and probably around 100-200 x the wight of a can of coke. Much of that weight would have been converted into light energy in a very short space of time when the object disintegrated.

It's mind boggling to think about it, but just imagine how bright an event like this might have been if the object had been 10x larger, and twice the speed! There are objects of this size and speed out there. Tunguska springs to mind!

[edit on 26-11-2009 by C.H.U.D.]

More footage...

Originally posted by C.H.U.D.
More footage...

Wow! I would love to see that!

Seriously I would be stood in a puddle of my own making grinning like an idiot and pointing skyward That's wicked!

reply to post by Now_Then


You and me too Now_Then...

Jaw firmly planted in the ground

Did you notice the way the lighting effect/color changed from frame to frame?

Talk about seeing the world in a new light!

Wow!

I would love to see that!

Seriously I would be stood in a puddle of my own making grinning like an idiot and pointing skyward

That's wicked!

Good GOD! That thing lit the Earth up as if it were day. That was wild. I think I would do same as you!

P.S. Star for you.

[edit on 26-11-2009 by av8r007]

If our solar system is going through the galactic center then isn't is going through a debris field basically? This might explain the increase in meteor activity.

reply to post by ViperFoxBat


Makes you wonder doesn't it? Going through a more debris ridden part of space would lend the Earth a little more risk wouldn't it? I'm not expert when it comes to things in space. Would make sense though. Though we do have two periods of high meteor activity in the spring and fall. Not sure what the exact weeks are.

Originally posted by ViperFoxBat
If our solar system is going through the galactic center then isn't is going through a debris field basically? This might explain the increase in meteor activity.

Patches of space where there are more rocks than normal would be inevitable, just as we would expect to see periods where the rate of these kind of events are low. That's nature.

There is a good reason however why we can rule out the galactic center as a source for these events we are seeing...

When an object orbits our Earth it is limited to within a certain speed range (up to around 10-11 km/s). Too slow, and Earth's gravity will cause it to enter the atmosphere and "burn up", just like a bit of decaying space-junk. Too fast and the object would escape Earth's gravity, and enter an orbit around our Sun.

The same principal also applies to objects in orbit around our Sun. Any object that is in orbit around our Sun, that collides with our atmosphere, will have a relative velocity in the range 11-72km/s.

If you look at objects that are in orbit around the galactic center, the same is also true. The minimum relative velocity of these objects would be at least 72km/s, and probably quite a bit more!

This jump in relative velocity would be extremely obvious to those of us who are familiar with meteors, but there is no evidence of that in this or any other well documented large fireball case.

So we can determine the origin of these objects as originating in our solar system on the basis of velocity alone, and in some cases where the meteor has been photographed, we can also calculate their orbits, which invariably originate in the asteroid belt.

That is not to say observers do not see galactic meteors from time to time, but usually they are caused by micro-meteoroids, and are more impressive for their apparent speed rather than brightness/size.



Edit to add some links to back up what I'm saying

Meteoroids travel around the sun in a variety of orbits and at various velocities. The fastest ones move at about 26 miles per second (42 kilometers per second) through space in the vicinity of Earth's orbit. The earth travels at about 18 miles per second (29 kilometers per second). Thus, when meteoroids meet the Earth's atmosphere head-on (which would only occur if the meteor were in a retrograde orbit), the combined speed may reach about 44 miles per second (71 kilometers per second).

Source: wikipedia

What do we know about real interstellar rocks? What, you say, are
there real interstellar rocks? Yes. In New Zealand there is a facility
called the Advanced Meteor Orbit Radar (or AMOR for short). It tracks
and determines the velocities and orbital properties of approximately
1,000 meteors per day. Of those 1000 meteors per day, about 2 are
interstellar in origin --- they have velocities in excess of the 72.43
km/sec which is the upper limit for bodies gravitationally bound to the
Sun at the distance of the Earth's orbit.

Source: meteorite-list mail archive


Continued:

Especially fascinating is the fact that when interstellar meteors
are plotted on the celestial chart and false colored for frequency, a
big "hot spot" develops smack dab on the location of beta Pictoris, a
star 51 light years away which is believed to be a solar system in
formation, with a big dusty disc which has been photographed.

The AMOR radars cover only 3% to 4% of the Earth's surface, of
course, so the 2 interstellar meteors per day that it observes means
that there must be 50 interstellar meteors per day falling to Earth in
total. And since the interstellar nature of these meteors is revealed
solely by their speed in excess of the perfect retrograde encounter,
there must also be detections of an equal number of prograde interstellar
meteors whose speeds are less than critical and so "escape the net." That
means there are really more like a total of 100 interstellar meteors
reaching the Earth per day.

If you draw a sphere centered on the Sun with a radius equal to the
Earth's distance from the Sun, you have created a surface that an
interstellar meteor has to cross to hit the Earth. (Actually, it has to
cross it twice, once inbound and once outbound.) If you cover the sphere
of the Earth's orbit with patches the size of the collisional cross
section of the Earth, it takes about 2 billion patches to cover the
sphere, which means that the Earth has about a one in a billion chance
of of being hit by any object that crosses the sphere (twice, remember).
If 100 interstellar meteors hit the Earth per day, then that means
that 100 billion interstellar meteors cross the sphere of the Earth's
orbit every day, or 18 trillion interstellar meteors per year. You know,
that's a one hell of a lot of interstellar meteors!

Of course, they're little meteors, about 40 microns in size. It
would take 1,500,000 of them to weigh a gram. A gram is about what a one centimeter interstellar meteor would weigh.

We can compute the likelihood of a bigger (or smaller) object that
the ones we observe by using the power law. The power law says that in a
randomly produced assembly of different sizes of objects each size class
possesses equal mass. For example, in a population of asteroids with
1000 one kilometer ones, there will be only 100 two kilometer ones and
only 10 four kilometer ones. The numbers are declining but the mass in
each class is the same. This techniques is widely used and accepted in a
variety of applications.

So, if the sphere of the Earth's orbit is crossed by 36 trillion
(36,000,000,000,000) 40 micron interstellar meteors per year, there will
be about 36,000 one centimeter ones crossing it per year. Since the
Earth has a one in a billion chance of being hit by such objects, that
would imply the Earth is struck by a 1-cm interstellar meteor every
27,778 years. During that same time, it would have a one in ten chance
of being hit by a 2-cm object, a one in a hundred chance of being hit by
a 4-cm object, and so on. The total can be adjusted by a factor of
1.11111... (ain't decimals grand?)

That brings the mean time between hits of a 1-cm or larger
interstellar meteor to 25,000 years. 25,000 years is a long time... but
it sure as hell ain't as long as a billion years.

One objection might be that dust-sized particles may be
over-represented because collisional efficiency increases as the
particle sizes get smaller. The frequency of 1-cm interstellar meteors
calculated by the power law is less that 1/300 of 1%, considerably
smaller than the incidence of 1-cm and larger objects in the infall of
asteroidal dust and conventional meteorites to the Earth.

Of course, the other real problem is that interstellar rocks are
moving fast. A landing on Earth is going to be tricky. But NOT impossible...
UNQUOTE

And, of course, these odds are derived from the very, very quiet
interstellar neighborhood we are in right now. At many times in the past, the Sun has spent tens of millions of years travelling through much more crowded stellar environments where the odds of an interstellar rock arriving would be hundreds or even thousands of times greater than they are now.


Sterling K. Webb

Source: meteorite-list mail archive


There has even been at least one reported case where an intergalactic meteor particle was detected.


[edit on 27-11-2009 by C.H.U.D.]

For some reason, I thought this footage had been posted on this thread, but it must have been one of the other threads on this subject.

This is the best footage of all, and I recommend downloading it (Right-click link, choose 'Save Link As...', and rename file to video.flv) and watching it with a suitable FLV player like this one



I captured frames from the first clip in the footage to produce the following sequence of images:



Here's a rundown of notable points and features in the frames:

Frame 1
Before the meteor appears.

Frame 2
The meteor appears at the top of the frame, and is already bright enough to light the surrounding landscape up as if it were a moonlit night.

Frame 3
The meteor continues to brighten. The sky appears as if it is just before dawn.

Frame 4
The surrounding landscape is lit up like a hazy early-dawn morning.

Frame 5
Most of the sky is now so bright, that the camera's sensor is overloaded.

Frame 6
Almost all of the frame/sensor is overwhelmed with the brightness.

Frame 7
The fireball is now so bright that the camera's sensor is completely overwhelmed.

Frame 8
There is a brief flicker as the light level starts to drop.

Frame 9
Once the light levels drop down enough that the camera's sensor is no longer saturated with light, the remnants of the fireball can be seen glowing in the sky. See below for a close-up.

Frame 10
Just a glowing persistent train is left in the sky where the fireball exploded.

Frame 11
The train has all but vanished.


Here is a close-up of frame 9:


Unlike most other meteor photographs which capture the motion of a meteor over time, this one shows the glowing plasma cloud created by the meteor after the event, as it's cooling down.

The upper part of the glowing train (the tail) is where the meteor probably hit a lower and and increasingly dense patch of atmosphere, and the forces on it would have built up to the point where the meteoroid could no longer endure them. The meteoroid appears to have started to disintegrate at the point labeled "A" (probably around 11 to 27 km), and the point of peak light production would have been at the point I've labeled "B".

At the point labeled "C", you can see the trail produced by a surviving fragment, which is usually a good indicator that something may have made it to the ground. Here's an example caught on a high frame rate camera Source: Fireball event of October 15, 2008.

Calculations estimate meteor lit up 500,000 miles

SALT LAKE CITY -- Space buffs have some astounding new calculations about the gigantic fireball that lit up our part of the west two weeks ago. They now estimate the meteor lit up 500,000 square miles bright as day, and they've learned a lot more by studying some spectacular images.

A lot of what people thought is turning out to be wrong. The Nov. 18 fireball was apparently much higher and farther away than it appeared, never closer than 120 miles to Salt Lake City, which makes its brightness all the more amazing.

Source: ksl.com