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4K Video of lunar meteorite impact!

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#26 Joe F Gafford

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Posted 23 January 2019 - 11:37 PM

You can find more of these impactor images on the spaceweather.com website

 

Joe



#27 Codbear

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Posted 24 January 2019 - 01:24 AM

We can do some off-the-cuff calculations to get an idea of the energy involved here. From an astronomy article I read, they used the brightness of the flash with the distance to the Moon at that point and arrived at an approximate mass of about 4 kilograms for the meteor.

 

Assumptions: Mass - about 4 Kg (about 9 pounds)

Velocity:                     22 miles per second, or 35,000 meters/second (could easily have been twice or half that so I'm splitting it)

 

Kinetic Energy (KE) = 1/2 MV^2

 

KE = (.5)(4kg)(35,000)^2

 

Kinetic Energy = 2,450,000,000 Joules

 

So how can we express that in terms that we can relate to more easily?

 

How about my F150 slamming into the moon at about 3,500 mph...ok that's still a little tough!

 

Maybe this one? An 80,000 pound 18 wheeler smacking into the Moon at about 300 mph

 

Or lastly, what if we took the Einsteinian rout and decided to collect dust particles off all of our instrument's

objectives, mirrors and eyepieces and convert them to pure energy (if we could of course).

How many would we need to convert to pure energy to equal the energy of

our 18 wheeler going 300 mph...?

 

Only about 3,500 dust particles, or less than a thousandth of the weight of a penny...crazy stuff!!!


Edited by Codbear, 24 January 2019 - 05:36 PM.

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#28 doctordub

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Posted 24 January 2019 - 10:53 AM

Fantastic catch! 

CS

Jonathan


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#29 hamishbarker

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Posted 24 January 2019 - 04:30 PM

I guess next lunar eclipse recording video with a star analyser grating might be worth trying to catch an impact flash spectrum.
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#30 darthwyll

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Posted 24 January 2019 - 05:33 PM

Codbear that is some fantastic calculations. I'm no expert but, to me, the object size seems on the small side. My gut tells me this thing should have been about the size of a work-out ball or large beach ball. I have nothing to base this on, just visual observation and a guess. How are they calculating the size/mass?

I spent some more time with the data and did an overlay of the un-eclipsed moon and the impactor moon. I too pinpoint the crater to probably be in the Lagrange G or H area. But again, those are just my estimations. Isn't this fun! New video linked below. :)

 

https://youtu.be/mra2K6358yw



#31 darthwyll

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Posted 24 January 2019 - 05:36 PM

Also my original video has gone viral. 148,000 views in about 48 hours. Unreal!



#32 TOMDEY

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Posted 24 January 2019 - 05:52 PM

It was probably too small a meteorite to detect the site of impact, but I tried anyway as I performed a whole moon mosaic just after the whole eclipse ended.  Seeing was actually quite poor, so resolution is not great (probably best crater resolves were in the 3 to 4 km range with the flat lighting).  In any case, I overlaid a video frame of the impact over my mosaic, and then also performed an overlay at the same image scale as my scope with LRO data which is much clearer, but I wanted to see if I could detect any change.  I didn't detect anything, but it would be interesting to see if it were possible with a larger scope under much better lighting and seeing conditions would be able to.  I'll post what I have to see if anyone will find it useful to see if they can detect a new crater.

The image below is the whole moon with an overlay of the video image where the flash from the impact is noted somewhere close between Legrange H and Legrange C.

Here is the closeup of my image taken shortly after (obviously on the left), and then a section of LRO imagery on the right.  The flash is seen as a white overlay in both images.  I certainly didn't detect anything with my equipment, but hopefully it is possible someone else might be able to.

Cool stuff.  As far as detecting evidence of the impact crater from Earth, you can forget about it!  Most impactors range in size from a grain of sand to a small pebble, and according to NASA, even an impactor of about 5kg (fairly large by these standards) would "only" generate  a crater of about 9m in diameter.  LRO has detected some evidence of new impact craters, but from Earth all we get is the light flash.  Very cool that so many people managed to image the same event.  Not too surprising when you consider the popularity of a lunar eclipse, and the fact that it represents a good time to detect the flashes.  

Cool! Excellent that you did that... but an impact big enough to show an after-signature, detectable from earth... wolud have to be WAY bigger. There is one single historical observation, where a (I think it was a monk?) noted a lasting flare on the moon, that now seems coincident with a suspiciously "fresh" small crater, as imaged by lunar orbiters.    Tom



#33 Tom Glenn

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Posted 24 January 2019 - 06:22 PM

I'm no expert but, to me, the object size seems on the small side. My gut tells me this thing should have been about the size of a work-out ball or large beach ball. I have nothing to base this on, just visual observation and a guess. How are they calculating the size/mass?

 

Apparently by the size and duration of the flash they can estimate the energy, and from there the size of the impactor.  Meteors tend to be fairly dense, some as much as 7-8 g/cm^3, although it looks like the average density is more like 4g/cm^3, and this one probably came from a comet, which is very low density.  So your beach ball estimate may be correct in terms of size, but the object didn't have very much mass.   A dense meteor the size of a large beach ball would weigh nearly 500kg, whereas this impactor is predicted to be much smaller...maybe 100x smaller in terms of mass.


Edited by Tom Glenn, 24 January 2019 - 06:22 PM.

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#34 Orion58

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Posted 26 January 2019 - 01:05 PM

Great catch!  I went through my data - I was taking single exposures with a modified DSLR.  I have captures at 22h41m23s and 22h41m50s (CST).  According to Sky & Telescope the impact occurred at 22h41m38s (CST) - right between the two....dang....

 

Nicely done.


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#35 Jeff B

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Posted 29 January 2019 - 10:45 AM

Actually one could calculate the kinetic energy involved if one wants to.  Assume the size of a basketball, the density if it's rock or metal and a speed.  KE = 1/2 x M x V-squared.  Do it joules.

 

Might be fun to convert it to kilotons of TNT.  Now, 4,184 joules of energy are released for each gram of TNT exploded.  Then convert the grams to pounds.  You may want to multiply by some fraction to account for losses in the explosion.

 

BOOM!  bombdrop.gif

 

And if you wanted to go full bore geek:

 

https://www.lpi.usra...usermanual.html

 

Have fun.

 

Great video!

 

Jeff



#36 David Knisely

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Posted 30 January 2019 - 09:25 PM

Silly question, why is there a light flash?  Is there enough of an atmosphere to cause a meteorite to burn up on entry?

 

Regards,

 

Dan 

 

No, the moon has no significant atmosphere, so despite the improper term "meteorite" being used, meteors or meteorites can't happen on the moon (unless, of course, someone was silly enough to raid a museum for one of its meteorites, put it on a rocket and send it to hit the moon :-) ).  When the meteoroid hit the moon, it was traveling at an extremely high speed (probably in the 20 to 30 km/sec range).  The kinetic energy of, say, a mere 4 kg (8.8 lbs) rocky body moving at 20 km/sec is a whopping 800 million Joules, and all that kinetic energy has to go somewhere.  In this case, it very rapidly heated the meteoroid and the lunar surface material immediately around it to a very high temperature, creating the little flash we saw from Earth.  The meteoroid itself was very probably destroyed on impact and some of the kinetic energy dispersed at impact probably also created a modest impact crater as well.  Clear skies to you.


Edited by David Knisely, 30 January 2019 - 09:32 PM.


#37 TOMDEY

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Posted 31 January 2019 - 04:13 AM

OOPS!

 

Well, for a moment, I thought I had a brilliant idea... and now it seems rather stupid:

 

Anyway, here it is; what do you think? >>>

 

>A few lunar orbiters that continuously monitor all of the moon for flashes at typical video rates or faster.
>One or more low-altitude lunar orbiters that micro-map all of the moon at high resolution, refresh e.g. once a month.
>analysis that correlates the above, looking for delta surface signatures at flash locations.
>additional exhaustive analysis that looks for any changes, anywhere on the lunar surface.

 

Actually, the top three are probably already being done, to some extent.
But the last one would be terribly difficult due to the ever-changing lunar illumination.

 

The dedicated program would be credited to my brilliance, but paid for by filthy-rich billionaires, who don't need so much money.   Tom, the magnanimous



#38 Jeff B

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Posted 02 February 2019 - 10:58 AM

We can do some off-the-cuff calculations to get an idea of the energy involved here. From an astronomy article I read, they used the brightness of the flash with the distance to the Moon at that point and arrived at an approximate mass of about 4 kilograms for the meteor.

 

Assumptions: Mass - about 4 Kg (about 9 pounds)

Velocity:                     22 miles per second, or 35,000 meters/second (could easily have been twice or half that so I'm splitting it)

 

Kinetic Energy (KE) = 1/2 MV^2

 

KE = (.5)(4kg)(35,000)^2

 

Kinetic Energy = 2,450,000,000 Joules

 

So how can we express that in terms that we can relate to more easily?

 

How about my F150 slamming into the moon at about 3,500 mph...ok that's still a little tough!

 

Maybe this one? An 80,000 pound 18 wheeler smacking into the Moon at about 300 mph

 

Or lastly, what if we took the Einsteinian rout and decided to collect dust particles off all of our instrument's

objectives, mirrors and eyepieces and convert them to pure energy (if we could of course).

How many would we need to convert to pure energy to equal the energy of

our 18 wheeler going 300 mph...?

 

Only about 3,500 dust particles, or less than a thousandth of the weight of a penny...crazy stuff!!!

Hey, I didn't see your post but using the conversion of 4,184 joules of energy are released for each gram of TNT exploded, I get ~1290 pounds of TNT.  I think your assumed weight is a bit low if the assessment is that it was basket ball sized but the amount of TNT yield scales directly with weight.  So a blast of anywhere from 1 to 10 tons of TNT.  

 

There have been photos taken from orbit of the lunar impact sites of the spent Saturn V S-IVB third stages.  I believe there were some TNT equivalent yields calculated for those too, much bigger mass but also much slower impact.

 

Jeff


Edited by Jeff B, 02 February 2019 - 10:59 AM.

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#39 Codbear

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Posted 02 February 2019 - 08:34 PM

Jeff,

 

I got the 9 lb quote from an interview with an astronomer at an observatory in Chile. Yes, since the mass is linear and the velocity is squared, a lot of speed makes up for a little mass pretty easily.

 

I couldn't help but notice that the energy yield for 1 gram of TNT is almost exactly 1,000 times the specific heat of water (4.186 joules/gram per C*)...wonder if there is some underlying relationship there

that doesn't meet the eye.



#40 Knygathin

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Posted 06 February 2019 - 01:16 PM

... according to NASA, even an impactor of about 5kg (fairly large by these standards) would "only" generate  a crater of about 9m in diameter. ...  

 

It sounds odd to me that a 5kg meteorite hitting the Moon with such enormous speed and the tremendous release of energy on impact, not should cause a crater much larger than 9m in diameter?! The moon-dust should be pushed "hundreds" of meters to the sides!?

 

Has any observer actually ever witnessed in their telescope (at high magnification) a meteroite impact along with the instant appearance of a new crater on the Moon surface?


Edited by Knygathin, 06 February 2019 - 01:21 PM.


#41 Knygathin

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Posted 06 February 2019 - 01:25 PM

It sounds odd to me that a 5kg meteorite hitting the Moon with such enormous speed and the tremendous release of energy on impact, not should cause a crater much larger than 9m in diameter?! The moon-dust should be pushed "hundreds" of meters to the sides!

Perhaps it is because there is no atmosphere gas, ... only vacuum. But still ...?



#42 Tom Glenn

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Posted 07 February 2019 - 04:38 AM

It sounds odd to me that a 5kg meteorite hitting the Moon with such enormous speed and the tremendous release of energy on impact, not should cause a crater much larger than 9m in diameter?! The moon-dust should be pushed "hundreds" of meters to the sides!?

 

Has any observer actually ever witnessed in their telescope (at high magnification) a meteroite impact along with the instant appearance of a new crater on the Moon surface?

9m is a pretty impressive crater for an impactor that is only 5 kg.  In this case I think the impactor is believed to have been part of a comet, which is actually not very dense, but if it had been an iron rich impactor, a 5kg object would be quite small in volume, only slightly larger than a softball in size.  So a ~30 foot crater is pretty big considering.   

 

Regarding witnessing a new impact crater 9m in diameter, that's not possible from Earth.  Just to put things into perspective, it's not easy to visually resolve craters below 1.5km in diameter, even in telescopes above 8 inches in diameter.  Conditions have to be very good, and even then it's challenging on the eyes.  Imaging can resolve somewhat smaller craters, but even here, most scopes top out at about 1km on the Moon in good conditions, until you go above 10 inches in aperture.  At this point, the atmosphere is extremely limiting, such that there aren't many images taken with Earth-bound telescopes that resolve craters under 500m diameter.  I have seen a few examples of sub-500m craters resolved from Earth-bound telescopes, but they are from scopes above 20 inches in diameter and operating under good conditions with a skilled imager (often 1m aperture scopes at professional observatories).  Even Hubble has a theoretical limiting resolution that equates to about a 90m distance on the Moon.  So to clearly resolve a new impact crater of 9m diameter, you would either need a space telescope like Hubble with 10x the aperture (this would be 24m!), or you need to get much closer to the Moon.  The Lunar Reconnaissance Orbiter is orbiting at ~50km altitude, and can resolve down to about a meter, so that is what we would need here.  


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#43 Knygathin

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Posted 07 February 2019 - 07:11 AM

Thank you Tom. I wonder though if someone ever was lucky enough to observe the happening of a new impact crater that was large enough to be seen in his/hers telescope? The Moon's surface is riddled with them.



#44 aeroman4907

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Posted 13 February 2019 - 07:29 PM

I found some imagery taken with the 1m Chilescope that possibly has crater resolves somewhere in the 400 to 450 meter range.  Tom is indeed correct, you need to have the LRO to detect such craters.




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