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.


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

2009 09 24 Kelowna-Yarrow Fireball

On the morning of the 24th of September I (Jeff) reported the following event to the BCMN list:

It occurred on September 24, at 09:56 UT which puts it at 02:56 PDT. It was very low on my SSW horizon. It was very slow moving with several bursts.

I then wrote Alan Hildebrand, and sent on the same information and asked him if he had any reports other than mine. He said not yet. I then sent him the movie of the bolide, a composite still picture of it and a light curve of the event. It seems most of my fireballs are low on my horizon so not that spectacular looking compared to a near zenith event.



Here is the light output graph; the total amplitude is the summation of all pixels above the triggering threshold.

Light Graph of the bolide


Ken Tapping, who would have a better view of it since his camera is south of mine reported back that he could not check his camera because he is out of town. No one else in our group recorded it. The terminal burst looked like it might have had a chance to be recorded by infrasound. I inquired Kris Walker and asked it was heard on the USArray infrasound array. He replied it had not.

Alan reported the fireball to the MIAC group and noted on human visual sighting from a person in Yarrow (west of Chilliwack), B.C. The report stated:

Yarrow BC
V2R 5C5
phone_home: 604-328-2864
date: 24/09/09
time: 02:50:00 am
cloud: none
latitude: 49.04585724220807
location: Just an estimate. It appeared to have landed in this mountain range.
longitude: -122.05484390258789
duration: 3
speed: Fast
flares: White ball with a colored centre. Large stadium sized bright dome of light on impact
colour: White
train: Yes, 0.5 sec
sound: Sharp
stime: 2

Note: The data folder is in the video data download category for West Kelowna/Sandia/2009_09




Sentinel Magnitude light output file

I asked Joe Chavez at Sandia National Labs what was contained in the single text file Sentinel outputs from the external video grabber.

It has this basic format:

From the Bolide of March 23, 2008

Event time: Sat 2008/03/22 04:26:41.04

-30     0       0   156.8   338.0
-29     0       0   156.8   338.0
-28     0       0   156.8   338.0
—- SNIP —-
233  1602   36538   226.4   329.6
234  1595   34884   225.4   330.2
235  1574   33285   224.5   330.7
236  1581   31824   223.6   331.3
237  1539   30273   222.5   331.9
238  1577   28940   221.4   332.3
239  1557   27557   220.3   332.8
240  1582   26090   218.9   332.9
241  1592   23868   217.2   333.3
242  1636   23007   215.7   333.3
243  1685   21843   214.1   333.4
244  1702   21038   212.6   333.6
245  1708   19880   211.1   333.6
246  1760   18637   209.6   333.6
—- SNIP —-

299     6       0   164.1   342.0
300     9       0   164.1   342.0
301     3       0   164.1   342.0

Joe informed me:

The first column shows frame counts, so each row represents about 1/30th of a second.  The recording begins 30 frames (one second) before the system is triggered.  The time stamp corresponds to the trigger time.

The second column shows the number of pixels that were above the threshold value.

The third column is a measure of the total amplitude and is computed by summing all pixel values above threshold.  Since this value may change depending on what hardware you use, you will need to calibrate it against a known light source.  We have done this by uncovering the shadow of the full moon over the sentinel camera and recording the amplitude response of the sentinel event.  If you measure the amplitude response of the full moon to be XM, you can calculate the magnitude of any event of amplitude X with following formula:

Magnitude = -12.6 – 2.5 * log10( X / XM ) 

This assumes that the magnitude of the full moon is –12.6

The fourth column lists the X coordinate of the centroid of the event, in pixel units.

The fifth column lists the Y coordinate of the centroid of the event, in pixel units.

I have a request in to find out if the new WSentinel (internal video card) light data file uses the same equation for magnitude estimates.

Update: September 04, 2010 17:42:24

Dick Spalding responded to my WSentinel inquiry:


Regarding your magnitude question, I think the scaling for the new video card system should be the same as for the Sentinel box systems. However, you should be aware that for very bright events, the camera’s auto-iris feature will begin to reduce lens aperture, thus reducing the apparent brightness of the event.  I don’t believe the full Moon causes the iris to be reduced, since planet brightness seems to be the same with or without the full Moon present.  Iris control is based on total light on the camera’s CCD chip.  So, a bright nearby light could potentially affect sensitivity by partially closing the iris.

Also, these HiCam HB-710E cameras have a built-in automatic gain control (AGC), which increases electronic gain as the scene becomes darker. For the typical dark sky, the gain is at the maximum permitted by the screwdriver AGC setting on the camera back.  Turning that setting to its maximum clockwise position gives the camera maximum sensitivity.  However, the resulting electronic noise produces an image with lots of “snow”, which forces trigger thresholds to be set higher.  Cameras that we ship usually have their AGC control backed off to a level that puts the snow below the default trigger threshold.  At that setting, I don’t think the presence of the full Moon causes the electronic gain to be reduced. Whether that’s true could be tested by lowering the threshold until random triggering on the snow begins to occur on a dark sky, then repeating with the full Moon in view.  I have not done that test.

Dick Spalding

Other papers on the calibration of an all sky lens

Here are more papers on all-sky lens calibration:

A new positional astrometric method for all-sky cameras.

This link will take you to the SAO/NASA ADS Astronomy Abstract Service where you can download the pdf. Below the abstract select Printing Options and then Print Whole Paper. Next press the send pdf button. A download of the pdf will follow.

Segon, Darmir, (2009) How many stars are needed for a good camera calibration? WGN 37:3, pp. 80-83.

Houghton, John (2008) Lens Calibration Using the Stars. Web page.






Sentinel Camera Calibration

In December of 2008, after a series of back of the envelope type discussions on how to calibrate a Sentinel camera, Ken formalized the discussions in a pdf. To see Ken’s method Click here for Ken’s original paper on how we can calibrate the Sentinel camera.

As a footnote I (Jeff) did a work through with my camera system. After the spreadsheet was made and a small Python program run Ken took my results and plotted it to see how his model stood up. Here are those results.


Hi Jeff,

I could not resist having a quick look. Your data is lovely. I simply plotted

R = sqrt((x-x0)2+(y-y0)2)

against zenith angle.

In the first plot I assumed the camera zenith was (371,240), and in the second I optimized it, and got (370,231). This of course would be the camera zenith not the centre of the frame.

HOWEVER: Look at the nice clean plot and good correlation. I think you can use the camera zenith method and ignore trying to find the centre of the frame; they are obviously very close because the plot, including the very slight nonlinearity due to the fisheye effect, integrates so cleanly.

The very slight fisheye effect can be approximated more than adequately by a 2nd-order polynomial, as Martin Connors said it would.

I would say, for your system, you should be able to simply calculate R and use the equation to get the zenith angle, and then do a rotation to find the azimuth error…. job done.





2009 11 08 Prince George Fireball

On November 8, 2009, Wayne, at RDL Observatory, reported a capture of a bright fireball to our network. He told us:

Late night capture, direction of travel westward. Event seen at Telkwa BC. UFO analyzer places impact area some where in the Terrace / Telkwa area but calibration of ufo analyzer is uncertain.  Witness at Telkwa said phosphor like drops falling between him and hill 1 mile to his north.  No Sound heard. enjoy

Wayne sent a movie of the event to the BCMN group. You can view it here:


Upon receipt of Wayne’s report Brower wrote Alan Hildebrand, Coordinator of the Canadian Fireball Reporting Centre, and asked if he was getting any additional reports of the event. He said he had not heard of the event.

In between e-mails Hildebrand checked back in his mail and found the alert Wayne had sent earlier. (It’s always  good to follow up if you don’t hear back).

CBC carried and article the next day. You can view the article by clicking here.

On November 9th Hidlebrand (personal communication to Brower) summarized to the MIAC group. The fireball was:

  1. Seen widely.
  2. It caused explosive booms and cast ground shadows.
  3. He estimated the fireball to be in the  -17 to -18 magnitude range.
  4. Estimate ‘conservatively in 100 kg to 1 tonne order of magnitude’.
  5. Had an east to west motion (and apparently some south to north and at least modestly steep) which would be reasonable for prefall orbits.
  6. Was probably a meteorite dropper.

No other BCMN camera recorded the fireball.


Sentinel III system in photos

The Camera and Housing

The housing for the camera, the anti-dew heater, the thermostat, and fan are all housed inside a PVC tube and toilet flange.
As packed for shipping. Stands approximately 0.5 meter tall.

Top shipping end removed reveals the camera and baffle.

Top Baffle

The Rainbow L163VDC4P fisheye lens mounted on the camera body. Note the PVC stiffener rods with coax cable running through it..

fisheye lens