[X] My Assistant

[jaredGalen]

Looks like the streak spotted back in March is most likely a bit of a comet called Wiseman–Skiff. According to this article

Fantastic little addition to Spirits 'research portfolio.'

[dvandorn]

This discussion points out why I have a certain distrust of mathematical models that predict real-world behaviors -- they often don't account for the occurrences that lie on the shallow edges of the bell curve.

It's all well and good to talk about the number of joules generated when a body enters an atmosphere, and describe on paper what happens to such a body when that many joules of energy are transferred to it. But such a simple calculation doesn't take into account such facts as abalone describes -- golfball-sized objects that survive entry into Earth's atmosphere and whose deeper structures aren't even significantly heated.

Models are good ways to understand how the real world works -- as long as you constrain your expectations as to exactly what you'll let those models predict. The real world is "fuzzy," it includes chaotic phenomenah that cannot be predicted by models. And models are always more simplistic than the behaviors they attempt to predict -- any model complex enough to predict all of the observed phenomenah in the universe will be no less complex than the universe itself.

-the other Doug

[Bob Shaw]

So: Some 'minor' (10KPS!) velocity differences between Earth and Mars impacting objects, no effective oxidation, some intense heating but also rather *little* heating in some cases. Presumably, strange shock effects here and there, too.

But: (and this is a big one) There *is* a huge difference between the dynamics of an object zooming through the upper atmosphere of the Earth and one heading for Mars. And it's this: the Martian atmosphere is thinner than ours, and goes out a bit further, and so on (but in many ways would behave like our own at a very high altitude) but it *doesn't* have a 1Bar surface pressure. Objects won't hurtle in then shatter on the 'hard' lower atmosphere, then drift to a halt on the surface. Instead, they'll keep going and I'd wager that their terminal velocities are *not* as on Earth! Volume (and mass) rise as the cube of the diameter, while surface area goes up only by the square, so small objects should be far less effectively slowed on Mars. We're talking about small objects hitting HARD.

I suppose the buckshot effect on some rocks *might* be impact created, then...

...(eating words previously uttered!).


Of course, there's the Heat Shield meteorite to consider...