Canadian Invasion

4 12 2008

I know you’ve seen this awesome video of a major bolide in Canada.

Here’s what you haven’t seen.

A guy I share a listserv with named Bruce McCurdy (Edmonton Space & Science Center) worked with a slew of folks to look for debris.  The official research crew was headed up by Dr. Alan Hildebrand, the leader of the team who investigated the famous Tagish Lake meteorite of January 2000.  The team also included Alister Ling, who co-writes The Sky Show with my good friend Martin Radcliffe in Astronomy Magazine (small world, huh?).  In all, a number of grad students, professors, astronomy club members, and a few other folks helped in the search.  They didn’t come back empty-handed…

marsden-meteorite-5

This was the largest of the pieces the team found.  Dozens of other gravel-sized meteorites were also collected, with practically all those found being handed over to the University of Alberta for analysis.  I have never gone on a meteorite hunt, but would certainly take a week off from work to do it if given the chance.

Bruce has set up a webpage with a slew of really cool pics from the search.  Before doing anything else today you MUST go there and check it out.

Bruce’s emails over the last few days have only thrown fuel on that fire.  Here’s a sample of what he’s been writing:

It’s been an exciting and tiring couple of days since last I wrote my first report Friday night from the Marsden Hotel in rural Saskatchewan. I’m now home safe and sound after two expeditions into the field to hunt for meteorites.

On Saturday morning Frank Florian and I continued our expedition as representatives of the Telus World of Science – Edmonton. We prowled the area by car, getting out to explore a few small ponds and examine various suspect rocks by the side of the road and in the ditches. Eventually we approached the farm where the original finds had been made. The farmer, Ian Mitchell, was hanging out at the entrance restricting access to just Dr. Hildebrand and his research crew from University of Calgary. He had met us the previous day during the media scrums when Frank had interviewed him on camera for a planned exhibit at TWoSE’s Space Place gallery, and I had passed him an RASC IYA2009 calendar in recognition of his good will towards the scientific community. Our own good will was repaid immediately, as rather than turn us away Ian said he realized we were serious in our pursuit, and directed us towards a remote group of beaver ponds in a corner of his property well away from other  searchers.

We headed in that direction, took a wrong turn and spent quite a little time on dry land exploring a cart path and a stubble field, still without success. There were many “meteor-wrongs” including terrestrial rocks, clods of dirt, vegetative matter such as wood chips, and animal droppings. With all my experience observing meteors I reassured Frank that we needed to persist, and that our patience would be rewarded. I added hopefully, “We need a little one for you, a little one for me, and a big one for the science centre!” Little did I know that was exactly how things would unfold.

Eventually we scrambled and slid down a steep and slippery embankment into the coulee where we located the beaver ponds. A preliminary scan turned up nothing, but on our second trip to the biggest pond Frank found a meteorite roughly 2-3 cm in all dimensions embedded in the ice. A  few minutes later I found one of the same size — what a thrill that was! A little while later I came across a somewhat larger specimen maybe twice as large that we had to chip free of the ice. Finally Frank found a very small meteorite of about 1 cubic cm.

We were running out of light so scrambled back up the embankment with our finds safely wrapped and stored. We returned to Ian Mitchell, who recorded our finds for Dr. Hildebrand but as I had hoped, told us to keep the meteorites we had found. We promised to bring them first to Dr. Chris Herd at the University of Alberta (Frank delivered them today), and once Chris is done with them, to use them for display purposes at the science centre. I am hopeful but not assured of getting “my” first, smaller fragment to use in conjunction with school and public talks. I expect I’ll be speaking frequently of the Lone Rock meteorites during IYA!

Tired and happy from our successful expedition, Frank and I returned to Edmonton late Saturday, our meteorites, images, and memories safely in tow. But at 6 the next morning, I was right back on the road, this time accompanying Edmonton RASCals Alister Ling and Franklin Loehde who were keen to do their own search. Even though I no longer had the “in” of officially representing the science centre I thought my local knowledge of the people and the area might be of use.

Alas, our ~six-hour search turned up nary a meteorite among the three of us. We explored the train tracks and some small ponds on public land which may have already been picked over or else they were outside the fall zone. As chance had it at mid-day we encountered Les Johnson and family; the discoverers of the large 13 kg meteorite had decided to return it to the land owner, Al Mitchell (brother of Ian). Les took us to the exact point where he had discovered the monster, and there was a ~10 cm deep indentation on the ground in which the meteorite fit perfectly. Les said he had actually found it just beside the hole; it had hit and bounced out. As it happened Al Mitchell was still in the area, as was Dr. Alan Hildebrand of U. of C., Dr. Martin Beech of the University of Regina, and the big meteorite itself.

The door to private lands thus opened, Dr. Hildebrand could scarcely refuse our offer to help, and for the rest of the day we traipsed through parts of the A.Mitchell property, through grassland and cow pastures, areas of heavy brush and frozen marshes where a broken ankle was a misstep away. Franklin took a tumble at one point and I nearly fell a couple of times, but luckily no harm done.  We tried to focus particularly on frozen ponds where meteorites will not survive the spring thaw. Our search was more exhausting than exhaustive … I’m sure it would take a coordinated team of a hundred people a week to properly search the full extent of the fall area, some of which is completely unsearchable.

The temporary webpage Bruce threw up has some really awesome pictures on it, but I hope he soon puts up a detailed webpage with his detailed descriptions of the hunt.  I’ve written him before about how great I think his writing is.  His narratives over the last few days have electrified my jealousy neurons to have been where he was.  Maybe he should consider writing up an article for a science magazine.  I’m sure some editors would love to have a first-hand account…  I’m just thinkin’ here Bruce!

In the meantime, I want you to look at this picture and tell me if you can see something interesting about the ice surrounding the meteor.

ellen-milley-1

Something really simple, yet completely amazing to me is causing the raised ice-ring.  What color is that frozen pond?  Now what color is the meteor?  That rock wasn’t discovered until nine days after the fall.  Though the temperatures didn’t get above freezing in that time, the sunlight was absorbed more easily by the black-colored meteor, which warmed it to a temperature above freezing.  This melted the ice in direct contact, and the meteor sank a little — displacing the water under it.  That water flowed away from the rock on top of the ice and refroze into that raised ring shape!

Physics wins again!

A special thank you to Bruce McCurdy for allowing me to post his pictures and his words.

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3 responses

5 12 2008
Bruce

Thanks for the kind words, Terry, it has indeed been an exciting time.

A couple of small corrections: only a handful of specimens — as far as I know for sure, just the four fragments that Frank Florian and I found — have been turned over to the University of Alberta at this point. The research team is headed by the University of Calgary which is where I would imagine the lion’s share of the scientific haul will wind up. But I don’t have any real inside knowledge of the academic side of things.

Also, the largest specimen wasn’t found by any team, but a private individual who later turned it over to the land-owner. There have been other specimens found on public land which belong to the finders as keepsakes or as sale items; it’s up to them. There is no obligation to even report these. I expect unauthorized people have snuck on to private land as well, and walked out with who knows what? We’ll never be able to keep a complete record of this fall, which will likely yield meteorite finds for years to come.

As for writing up a report for a scientific magazine, I am currently writing my regular column for the Journal of the Royal Astronomical Society of Canada on this subject. Perhaps I will submit something to SkyNews or one of the majors as well. Thanks for the vote of confidence!

5 12 2008
Nick Jones

Mr. McCurdy, I am amazed by your work and completely agree with Terry about your writing. You have a real talent fr portraying “the hunt”. I also really enjoyed the videos and pictures. The proof that the biggest piece was the size of a head because it had a hat on mad me laugh for a good minute.
Johnson, I totally thought that the different colors caused the depression before you even asked. I realized it because my first thought was, wow is was still hot enough to melt the ice underneath it, but then it occurred to me that there would be a slightly larger hole in the ice than that if that was the case. Just slightly lager…

5 12 2008
Terry Johnson

Thanks for those clarifications, Bruce. And again thank you for keeping us updated on your search.

Nick, good call on the melting ice! That’s one situation in which black-body dynamics really stands out. Imagine melting ice in constant sub-zero temperatures just from being the right color.

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