from the imagine-how-many-go-down-storm-drains dept.
Scientists have discovered significant numbers of "large" micrometeorites collected from the debris found in urban rooftop gutters:
For years, amateur astronomers have been suggesting that microscopic, spherical particles collected from their roofs are actually tiny meteorites, the dust that formed our Solar System fallen to Earth. Scientists took the claim at face value but ended up being the downers again, at least initially. [...] One of those amateurs is a Norwegian artist and jazz guitarist named Jon Larsen, who created a group called Project Stardust. Larsen managed two impressive feats to get the issue revisited. One, he convinced people in Oslo to gather materials from their roof gutters (although, oddly, one sample also came from Paris). And not just a few—material came in from buildings that collectively possessed 30,000 square meters of roof.
The second feat was that Larsen got a small international team of scientists (Belgian and UK) to take this seriously. Faced with about 300kg of roof debris, the authors separated the material using a combination of magnets and physical shape—micrometeorites are spherical because they melt during atmospheric entry and are shaped by the air. From that 300kg, the researchers isolated 500 particles, all just a few hundred micrometers across, that looked like they were micrometeorites. Forty-eight of them were chosen for detailed analysis. All 48 of them appear to be genuine micrometeorites.
An urban collection of modern-day large micrometeorites: Evidence for variations in the extraterrestrial dust flux through the Quaternary (open, DOI: 10.1130/G38352.1) (DX)
(Score: 2) by butthurt on Wednesday January 25 2017, @11:51PM
The article says:
[...] the sediment samples were processed by magnetic separation, washing with water, and size fraction separation.
Yet they say they identified forsterite, which is Mg2SiO4. I wouldn't expect that to be attracted to a magnet.
https://en.wikipedia.org/wiki/Forsterite [wikipedia.org]
(Score: 4, Informative) by takyon on Thursday January 26 2017, @12:05AM
In other words, micrometeorites aren't going to be pure Mg2SiO4, and may even be lumped in with some magnetic iron.
https://en.wikipedia.org/wiki/Micrometeorite [wikipedia.org]
[SIG] 10/28/2017: Soylent Upgrade v14 [soylentnews.org]
(Score: 0) by Anonymous Coward on Thursday January 26 2017, @12:16AM
They work like the tides. Tide comes in, tide goes out. You can't explain that.
(Score: 0) by Anonymous Coward on Thursday January 26 2017, @12:35AM
it can be explained only if you DO IT LIVE!
(Score: 2) by MichaelDavidCrawford on Wednesday January 25 2017, @11:57PM
"OK but why?"
"For SCIENCE!"
Yes I Have No Bananas. [gofundme.com]
(Score: 3, Funny) by bob_super on Thursday January 26 2017, @12:05AM
Sure, it you want to clean and fix my gutters, you can keep everything you find inside.
May I interest you in analyzing my shingles? You only need to replace the whole roof to collect them for free!
(Score: 3, Funny) by Gaaark on Thursday January 26 2017, @12:14AM
"She blinded me! With... her gutter debris!"
--- Please remind me if I haven't been civil to you: I'm channeling MDC. ---Gaaark 2.0 ---
(Score: 5, Interesting) by moondoctor on Thursday January 26 2017, @12:48AM
There's an awesome book about the earliest air mail pilots and their crazy ass stories. One of my favourites is a guy whose plane conks out midair and he puts it down on a tall plateau thing in Africa that's the size of a few football fields and got sheer drops on all sides. Finding all these little round rocks that are completely different from the mountain and knowing that no person or animal had ever been up where he was he realises what has happened. The rocks had to have come from above. The description of the top of this flat mountain as 'a tablecloth set out to catch apples falling from the sky' over hundreds of thousands of years (paraphrasing) always stuck with me.
(Score: 2) by edIII on Thursday January 26 2017, @01:01AM
That was pretty cool. Thanks for sharing that.
Technically, lunchtime is at any moment. It's just a wave function.
(Score: 1, Funny) by Anonymous Coward on Thursday January 26 2017, @01:51AM
they killed the micro-dinosours!
(Score: 2) by JoeMerchant on Thursday January 26 2017, @04:57AM
So, for each pound of roof gunk, you might have (on average) one tiny micrometeorite.
I wonder what the distribution was, did they keep the sources separate? Did the concentration vary by latitude? Did all the micrometeorites come from just one or two roofs, or were they more evenly distributed?
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(Score: 2) by Pslytely Psycho on Thursday January 26 2017, @07:15AM
Seems like the perfect follow up study. In this instance, I believe the goal was just to prove their existence. Now it's time for a more detailed study.
Alex Jones lawyer inspires new TV series: CSI Moron Division.
(Score: 2, Interesting) by Tara Li on Thursday January 26 2017, @03:50PM
It makes just about TOO much sense - why would professional astronomers even question it? They might argue that the concentration would be too low to be worth studying, but the fact that they would be there? It's just too sensible. I'm going to throw this one, I think, in the basket with red sprites, rogue waves, and meteorites themselves. Scientists are just too willing to dismiss "untrained observers".
(Score: 2) by sgleysti on Thursday January 26 2017, @07:28PM
It seems you're saying that they should have tested this sooner, and I'm totally with you. On the other hand, any claim, regardless of how much sense it makes, has no necessary correspondence with reality -- it must be substantiated by empirical evidence. I'm so happy they finally tested this; it's such a cool phenomenon. Also, good on the guy who pushed to get it tested and the volunteers who donated sample material.
(Score: 1) by Tara Li on Thursday January 26 2017, @08:29PM
Perhaps. And yet - each time a chemist creates a new compound, they don't immediately turn around and test it to make sure it obeys the law of gravity. The idea that it *wouldn't* would be the thing so unusual someone would want to test it to make sure.
These meteorites are the result of small droplets of melted material either being pulled off by turbulence, or condensing from vapor, or of meteoroids entering the atmosphere too slowly or too small to be greatly heated by air resistance. The details are worth studying to determine what proportions are which, but the basic idea is so obviously within the bounds of known physics that I can't understand why an astronomer might have said "no, such a thing does not exist".
I *can* see an astronomer saying "it mostly likely happens but the amounts would not be easily detected", but that's a whole different matter.