2017-9-4 : Kaslo Bolide/Meteorite – by Rick Nowell

Last Sunday a huge fireball lit up Cranbrook’s whole western horizon.  From high up, first a swiftly moving ball of yellow light caught the eye.  It rapidly gained brightness, until it turned into a blue-white welding arc.  A small orange globule broke off and followed it along its wake.  Then it suddenly flared and a spray of brilliant white light flashed out and lit all the sky for miles around and casting shadows on the ground.  A large blue-white fireball zipped out of that dazzling light, with one smaller orange fireball chasing after it, slowing down and dropping over the horizon into the smoke haze until it dimmed out of sight.  Minutes later, a dull rumbling sound like thunder grumbled in the distance.

In disbelief a witness in Crawford Bay “almost ducked” as she saw it rocket close overhead, the eerie silent blue-white fireball and behind it two smaller reddish-orange balls falling away and arcing down not too far away to the North.  There was a quiet pause as she looked North wondering—what was that?  Then KRACK-WHAMMMM! recoiled to the tremendous crash of a sonic boom–so loud she felt it vibrate inside her chest, then a crackle and continuous waterfall of noise as the air tumbled back in to fill the tunnel of low pressure air the supersonic fireball had rammed through the sky.  For an endless twenty seconds this shook the house, rattling the windows, the garage doors and even the ground before dying away.  For a second she imagined it was a nuclear bomb blast.  I’m not kidding, it was that loud! she said.

Was it a small nuke?  NASA’s JPL website reported a monitoring satellite saw an air blast at 36km altitude equivalent to 0.13 kilotons of TNT.

Attachment KasloMeteor.gif above is a GIF slideshow with frames displayed every half second.  When viewed in webmail or on a web browser, it will play the animation.  Moon at lower left.  Photo credit COTR meteor cam 4 Sep 2017.

But videos show it was a meteor, a rock from outer space, with pieces falling off as it went along.

So, where did it hit the ground?  BC has a network of meteor cam stations watching to find where these hit.  The College of the Rockies has a meteor cam, and it tracked it for about ten seconds, starting from 11:11:26pm.   Six or more security cam videos saw it.  One good video from Spokane (near Gonzaga University) was used with the College video, and a photo from just South of Crawford Bay near the marina, to triangulate where the meteor hit and was able to give us a good idea.  Esko Lyytinen, a retired mathematician of the Finnish Fireball Network, kindly analyzed our video.  Summarized as follows:

The main 50kg piece would have hit about 5km East of Kaslo around: (49.8731 N,  116.8457 W).  “It flew directly over Crawford Bay but not as far as Meadow Creek”.  The main piece was last seen at 49.7603 N, 116.8350 W, still 18.9km high​.   The 100g sized fragment from the brightest flash would have hit 2.5 km South and 1km East of Riondel at around (49.7381 N, -116.8393 W).  The winds may have moved the main fragment about 750  m to the East and the 100 g fragments about 1.7 km to the East.  Thus the NE area of Crawford Bay would probably be favorable for finding fragments.  As well as from Gray Creek North to Crawford Bay along the road.   But fragments can veer in direction: after talking to witnesses, Dr. Alan Hildebrand is worried the main piece may have gone into Kootenay Lake. 

These fragmented meteors don’t make craters, craters are usually made by much larger solid nickel-iron ones.  This meteor was likely slowed down to around 200 km/h by the time it reached “dark flight”.  ​If the basket-ball sized 50kg chunk hit soft ground, it would have left a big dent about as deep as its diameter, then bounced up and landed on the surface again.   Unless it hit solid bedrock and shattered.  The smaller fragments (100g would be around golf ball sized) would have just bounced like normal rocks.

Meteorites that strike the ground are not smoking hot as depicted in Hollywood movies, so there is no need to worry about them starting a forest fire. They start off cold in outer space (about zero degrees C for meteoroids around Earth’s orbit).  Their outer surface gets white hot as it compresses the air into a plasma sheath, but this blowtorch heat is slow to penetrate the rock.  This hot layer fuses and evaporates and is blown off as droplets, dust and vapour before it can heat the inside.  So the inside remains cool during the brief 10 second fiery fall through the atmosphere. It’s rare to find a hot or warm meteorite, some have even been found with frost on them.  But the outside skin often has a one millimetre thick melted “fusion crust” with thumb-sized worn hollows.

Video Frame at 11:11:34.066 seconds showing fireball and pieces falling off along path (photo rotated).  Photo Credit R. Nowell, COTR Meteor Cam.

Judging from factors like how high it fragmented, porosity, speed, cometary orbit from beyond Pluto,  Esko is betting it’s a common, stony non-metallic meteorite, a “chondrite”.  These are the most common types, they make up 86% of meteorites that are recovered.  Formed of dust, clay and small sand grains surrounding “chondrules”: small beads of silicate minerals like olivine and pyroxene.  (Olivine is a magnesium iron silicate common on Earth but quickly weathered).  May contain small amounts of magnetite, nickel-iron, or even flakes of metal.   Density about 3.5 g/cm^3 as heavy as basalt rock.  Very old, from primitive asteroids originating from the early solar system 4.5 billion years ago

Chondrite Meteorite.  Polished face showing chondrules and metal flakes.  Dark shiny fusion crust.  Photo Credit H. Raab, CC Wikipedia article. https://en.wikipedia.org/wiki/Chondrite

Since it had a cometary orbit of about 50AU, Esko supposes it may even be a carbonaceous chondrite with lighter density.  That is a rare type of primitive meteorite with organic compounds such as water, amino acids and hydrocarbons.

WHAT TO LOOK FOR: Chondrites:   Look for rocks that a magnet will stick to.  The surface may have a thin grayish fusion crust (a thin melted layer one or two millimetres thick) and scattered thumb sized hollows (worn away by atmospheric friction called regmaglypts).  Although rarer meteorites like the Tagish Lake carbonaceous chondrite meteorite looked like black charcoal briquettes.

 

Ignore layered sedimentary rocks (shale, limestone, dolomite) since these require an ocean to form, and this wouldn’t be found on an asteroid in outer space.  Also, if it has holes or bubbles inside (like pumice) that was likely from lava flows (basalt-magma) cooled with trapped volcanic gases, on Earth (although there are rare exceptions: a large asteroid like Vesta had volcanoes).  Also, ignore rocks containing quartz or calcite, since they form in high pressure, hot watery solutions.

 

Magnets: Since a lot of chondrite types contain iron oxides like magnetite, and some metal rich ones contain nickel-iron chondrules, a rare-earth magnet should stick to most.

 

Value:  If a hiker finds a piece, it could be worth a lot of bucks per gram or it may be disappointing. Common iron meteors are only $.50/gram to $5/gram, rarer stony meteorites $2 to $20/gram, and really rare ones $100 or $1000/gram or more, depending if they have embedded gems or if they’re from Mars or the Moon. And some meteors are dense and heavy, so they go a long way. For example, back in 2000, the rare carbonaceous chondrite meteor that landed on frozen Tagish Lake on the B.C.-Yukon border brought Jim Brook, the lodge owner who found it an estimated $850,000. The University of Alberta, with Canada’s second-largest meteorite collection, bought most of the meteorite.  For sample meteorite pricing, see http://www.meteorlab.com/METEORLAB2001dev/offering21o.htm

The Washington University in St. Louis has a great webpage showing all sorts of meteorites at http://meteorites.wustl.edu/id/metal2.htm.

If you do find a possible meteorite, send a photo to Dr. Hildebrand.  Note that American Meteor hunters have to report to the Canadian Customs, Canada has export restrictions on them.

[meteorite_flow_chart.gif]

Above is a flow chart guide designed by Deborah Guedes in Brazil to help identify a meteorite.  http://www.lpi.usra.edu/meetings/metsoc2010/pdf/5357.pdf  “Regmaglypts” are those worn-away thumb sized hollows in the surface.

 

The College meteor camera has seen large fireballs or bolides of over 100 kg that hit the ground about four times in the past six years.  The last was:
– December 20, 2014 over Canal Flats, BC hitting by Marconi Peak on White Swan Lake road. This was possibly a rare carbonaceous chondrite.
– September 26, 2011 over Banff, AB, hitting in the park.
– May 14, 2011 over Creston, BC, hitting by Duck Lake.

With shared videos from other ground stations in the BC Meteor network, like West Kelowna, Penticton, Courtney, Vancouver or Prince George, we can triangulate where these have impacted to within 2 or 3 kilometers. We then have a chance to find these rare meteorites and to find out what they contain.

College of the Rockies also belongs to the Sandia National Laboratory North American meteor network, and we upload videos of fireballs to there.”​

Rick Nowell
Astronomy Lab Tech
College of the Rockies

Radio Detection Basics – Software – JAnalyzer

 

JAnalyzer

 

This software was also written by Esko Lyytinen and his son Öllie. It too is freeware.This written in Java so it can be run on any system that has Java installed on it. I have run this on Windows XP, Linux, Unix, and on an Apple iMac (Pentium).

Janalyzer is a lot more flexible than it’s ancestor, mAnalyzer. The user can control fft bin sizes, timing, rates of image scans, and data output.

Like mAnlayzer, JAnalyzer has a small footprint, the executable .jar file is only 118 kb in size.

I usually run JAnalyzer so it produces 3 FFT spectrograms. The first is a time compressed image that contains a full 24 hours in a single line. The image can store a week’s with of data in one image. I do this so I can see aurora, Es, lightening, and other sources of interference. Having a weekly time compressed image also aids in seeing weekly trends. The image below original size is 1043 x 680.

24 hours a line

All echoes seen in the time compression are over dense echoes. Normal duration echos are not seen at this compression rate. A careful look shoes the long duration echoes in the first row which is August 9, 2010, start off rather spotty. As we approach the peak of the Perseids on the 13th we see more and more over dense echoes.  The light gray blocks are created by man made noise, washer and dryers, microwave ovens, and arching AC lines during high winds.

The second FFT image is an image of the past 24 hours as seen below. This helps me easily spot overdense echoes that I might be able to correlate with the all-sky video camera. Original image size is 964×2750.

Daily August 13th Perseid peak

 

The  image above shows many overdense, long duration echoes. It also shows the noisy periods as well. if you look carefully you’ll see an occasional carrier streaking across the pass band. Hint the last line of the image at 1200 UT. Hash marks are at 1 minute intervals. There are two lines per hour – the shorter line is the end of each hour.

The third FFT image is a fast scan. It usually scans at a rate of an image every three minutes. It can run faster so head echoes can be seen.

(Reminder add fast scan image here).

A cursor over the start of an echo will show the frequency of the echo as well as it’s start time. Moving the cursor to the end of the echo shows the end time.

I have JAnalyzer set to generate 3 text files. One is a 10 minute file which is similar but not the same as the mdata file mentioned in the mAnalyzer section. It records four sets of power bins and the counts and duration of each bin. It also produces an hourly report much like it’s mAnalyzer counter part, mhdata. If my research problem requires it, I have the program write a line for every echo heard.

The individual raw echo file format is:

2010-03-03 14:20:37.487, 00003, 02.29745, 03.03210
2010-03-03 14:21:13.626, 00013, 02.61173, 03.79104
2010-03-03 14:22:17.924, 00042, 03.09038, 04.30555
2010-03-03 14:22:42.468, 00002, 01.22930, 01.31838

YYYY-MM-DD HH:MM:SS.sss Time stamp beginning of echo

Duration of echo (timing depends on fft buffer size) To determine duration count you divide buffer size by sample rate. I run several buffer sizes at 8000 samples per second. Buffers can be 256, 512, 1024, and so on. For example a one unit of duration recorded with a 1024 at 8000 samples per second = 0.128 of a second or 128 ms. And unit for a bin of 256 at 8000 samples/sec =  0.032 sec or 32 ms

Mean Audio power in log(2)  (That is, the mean of the logarithmic values)

Maximum power in log(2)

Radio Detection Basics – Software – mAnalyzer

 

mAnalyzer

This software was written by Esko Lyytinen and his son Ölle. It is freeware. It is not used by many observers any more as it is getting a bit dated. It does however,  have several features going for it.

  1. It can be used on old, less capable computers running Windows95 and up.
  2. It has a very small foot print memory and hard drive wise
  3. It is not a cpu hog.
  4. It automatically records four amplitude ranges and records the duration of echoes for each amplitude category.
  5. It prints files every 10 minutes and hourly
  6. The file output format is supported by Colorgramme/Color Lab so can be used for automatic ftp to the RMOB live site.
  7. A 24 hour spectrogram image is saved at the end of the day.
  8. It has the ability to notch out a carrier in the echo count pass band if needed.
  9. Compares a 100 Hz pass band for echo signals and compares it to a nearby noise band.
  10. No scripts or programming needed, it’s plug and play.
  11. Runs for months without attention.

For the reasons listed above I run mAnalyzer in parallel with Spectrum Lab as cheap insurance.  It has saved critical data several times over the year when others have failed for various reasons.

Here is a sample of the 24 hour image produced by mAnalyzer (size has been reduced):

mANalyzer 24 hr

Blue hash marks are minute marks, light blue are ten minute markers, and red are the hourly markers. It takes two line per hour. This compressed time scale is an aide in seeing Es, sporadic E interference, aurora, and broadband noise that often affect the counts. This image was produced on 2010-01-03, the day of the Quadrantids peak. As can be seen there are two bands of clustered echo returns. Between the two is a few hours with less echoes than either side. This is a somewhat common occurrence caused by the radiant of the shower moving through the 45 degree elevations of the station’s site (maximum echoes at the two 45 degree points).

The format of the hourly result file (mhdata.txt) looks like this:

201001031000    10    0.043271    206
201001031100    11    0.043342    221
201001031200    12    0.052527    274
201001031300    13    0.051171    272
201001031400    14    0.052452    288

YYYYMMDDHHMM  UT hour  duration (percentage of period) and echo count for the hour.

The 10 minute file (mdata.txt) has this format:

201001031400,0.956661,0.015585,0.016652,0.010675,0.000427,0.000000,0.000000,27.817250,   11,   19,   15,    1,    0
201001031410,0.945536,0.018368,0.022426,0.013669,0.000000,0.000000,0.000000,28.487399,   15,   17,   20,    0,    0
201001031420,0.950897,0.015585,0.024125,0.009394,0.000000,0.000000,0.000000,27.483348,   12,   20,   14,    0,    0
201001031430,0.942357,0.022630,0.025833,0.008540,0.000213,0.000000,0.000427,27.523708,   17,   19,   12,    1,    0
201001031440,0.952818,0.020068,0.020709,0.005978,0.000000,0.000000,0.000427,27.587142,   19,   16,   12,    0,    0
201001031450,0.936166,0.021136,0.023271,0.019214,0.000213,0.000000,0.000000,28.522844,   12,   16,   19,    1,    0
201001031500,0.963691,0.016446,0.013242,0.006621,0.000000,0.000000,0.000000,27.663178,   20,   19,   10,    0,    0

Left to right:

  1. YYYYMMDDHHMM
  2. Percentage of time with no signal
  3. Percentage of time with Level 1 echoes 1-10 dB
  4. Percentage of time with Level 2 echoes 11-20 dB
  5. Percentage of time with Level 3 echoes 21-30 dB
  6. Percentage of time with Level 4 echoes 31-40 dB
  7. Percentage of time with Level 5 echoes > 40 dB Not used
  8. Percentage of time with with possible noise or interference
  9. Audio Index shows jumps if receiver volume control or sound card sound input changes.
  10. Level 1 echo counts 1-10 dB
  11. Level 2 echo counts 11-20 dB
  12. Level 3 echo counts  21-30 dB
  13. Level 4 echo counts 31-40 dB
  14. Level 5 echo counts > 40 dB Not used

2015-11-13 : WT1190F – Play by Play BLOG

015-11-13 : 10:21 PST. Splashdown was last night at 22:19  PST in SRI LANKA off coast of Matara. Was late evening on USA Westcoast Thursday. Please enjoy my Blog. This is a conversation between young post-grad scientist Subath Amaradasa of the “Near Earth Objects” Team at the University of Ruhuna, who is on ground with French scientists from European Space Agency and William Smith who is the Hoyle-Shield coordinator at Cattle Point DARK SKY Urban Star Park, Victoria, Canada.

PS There will be a post script to the Snoopy event. Snoopy is almost certainly the Apollo 10 lunar lander – aka Snoopy. Its orbit which reaches way past the moon, makes this almost certain. No wonder it burned out. Very high speed entering the upper atmosphere. Ten times the speed of the fastest bullet on earth. Being small and with no shielding, no wonder it quickly burned out. Thanks to Rick Nowell for inspiring Subath Amaradasa and his “Near Earth Object” team at the University of Ruhuna in Matara, Sri Lanka.

The AllSky Meteor Cam at the College of the Rockies in Cranbrook BC

AllSky Geminids Stack 11 Frames

 

 

 

 

 

 

 

 

 

This is the College All-sky meteor cam showing the eleven brightest Dec 15 meteors stacked on one frame, from 7pm until 2am when it clouded over. North at top of photo and East to the left. Two bright fireballs on the horizon! That trail of dots there is Jupiter rising. Some clumps of dots are just aircraft strobes.

AllSky Geminids Stack 11 Frames

 

 

 

 

 

 

 

 

 

And here’s the 11 meteor stack for Dec 14 from 9pm until 1:15am, when it clouded over. About the same each evening.

Geminid Meteor StreakAnd just for fun, here’s all the photos stacked from the camera watching Ursa Minor over a 43 minute period, taken with 30 second exposures, 28mm f/2.5 lens, 1000 ISO.

Geminids from Invermere By Robert Ede

Geminids from Invermere

This photo was taken facing South, showing Orion before the Moon rose, from Invermere by Robert Ede. He says: I saw some beauties. A few with smoke trails.

WT1190F – Play by Play BLOG

2015-11-13 : 10:21 PST. Splashdown was last night at 22:19  PST in SRI LANKA off coast of Matara. Was late evening on USA Westcoast Thursday. Please enjoy my Blog. This is a conversation between young post-grad scientist Subath Amaradasa of the “Near Earth Objects” Team at the University of Ruhuna, who is on ground with French scientists from European Space Agency and William Smith who is the Hoyle-Shield coordinator at Cattle Point DARK SKY Urban Star Park, Victoria, Canada.

 

PS There will be a post script to the Snoopy event. Snoopy is almost certainly the Apollo 10 lunar lander – aka Snoopy. Its orbit which reaches way past the moon, makes this almost certain. No wonder it burned out. Very high speed entering the upper atmosphere. Ten times the speed of the fastest bullet on earth. Being small and with no shielding, no wonder it quickly burned out. Thanks to Rick Nowell for inspiring Subath Amaradasa and his “Near Earth Object” team at the University of Ruhuna in Matara, Sri Lanka.