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A comment on The Hoba meteorite, estimated at 66 tons, left no crater when it fell to Earth.

Re:The Hoba meteorite, estimated at 66 tons, left no crater ... by leeoniya on Saturday November 10, 2018 @12:27PM (#18422307)
> Scientists have suggested that the massive rock apparently slowed down as it penetrated Earth’s atmosphere. It slowed so much that the Hoba reached a point of terminal velocity as it was about to impact the surface

i don't buy it.

why couldnt it be part of a bigger impactor, so if it was just a shard that broke off after impact and flew mostly horizontally before settling?

maybe it struck the top of a thick glacier that has since melted?

maybe there were 200m of water in that location then?

terminal velocity for a meteor is 200-400mph. 66 tons at that speed would at minimum leave it nowhere near the surface.

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Re:The Hoba meteorite, estimated at 66 tons, left no crater ... by posterboy on Saturday November 10, 2018 @01:26PM (#18422659)
> why couldnt it be part of a bigger impactor, so if it was just a shard that broke off after impact and flew mostly horizontally before settling?

I agree, there could be any number of explanations. I haven't seen many meteoroids but the rectangular shape appears peculiarly unnatural, more like a fragment of a shell.

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Re:The Hoba meteorite, estimated at 66 tons, left no crater ... by innagadadavida on Saturday November 10, 2018 @01:27PM (#18422663)
No one seems to have proposed that it could have been magnetic and it interacted with Earth's magnetic field.
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Re:The Hoba meteorite, estimated at 66 tons, left no crater ... by vanattab on Saturday November 10, 2018 @01:52PM (#18422817)
I don't think the earths magnetic field is anywhere near strong enough to seriously effect a meteorites velocity.
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Re:The Hoba meteorite, estimated at 66 tons, left no crater ... by dysan819 on Saturday November 10, 2018 @04:02PM (#18423490)
You don't have to guess, you can do the math.

While you're at it, watch this, it's fun (and related): https://www.youtube.com/watch?v=sENgdSF8ppA

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Re:The Hoba meteorite, estimated at 66 tons, left no crater ... by raverbashing on Sunday November 11, 2018 @01:24AM (#18425252)
Yes, you can do the math. But "practical" intuition gives you a good sense of possible orders of magnitude, though, sometimes fails.

A compass needle is easily moveable by hand. Even Lenz effect forces (when only driven by magnets) are weaker than the attraction forces of the same magnet (depending on the speed, of course) though going east->west the flux doesn't change much.

So my conclusion is that, even though it might have had a small effect on it, absolutely not enough to make it change velocity significantly.

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