Old magnetic fields and early planets

After an unexpected wackiness in my schedule, I’m finally able to grab some moments to start posting again. A vacation is definitely needed at some point. *grumble*

In spite of the schedule, I managed to watch a surprisingly good game yesterday, despite a bit of sloppiness displayed by both the Steelers and the Cards. I expected Pittsburgh to win, but found myself hoping for a Arizona victory after that amazing 100 yard touchdown yards. But I can’t deny that it was an amazing catch that won Pittsburgh the victory touchdown.

Speaking of collisions and formations, I came across this article showing that meteorites show evidence of their formation in an early magnetic field. This is significant because we know that the earth’s magnetic field is likely formed by the rotating molten core (moving charges, or currents give rise to magnetic fields). From the article:

Most meteorites don’t make it to Earth unscathed. After repeatedly smashing into other objects and traveling through Earth’s harsh atmosphere, they can be substantially altered before crash-landing on the planet. But not angrites — a group of 12 stony meteorites that, at an age of about 4.56 billion years old, are among the oldest-known rocks in the solar system and somehow “got here without being messed up,” says Benjamin Weiss, a planetary geologist at MIT in Cambridge, Mass. Because these meteorites are pristine, angrites retain information about the larger body from which they came.

Angrites are also interesting because they are made of basalt. On Earth, basalt forms from magma derived from the mantle. Scientists think angrites similarly erupted from the interior of a planetesimal, Weiss says. This similarity suggests that the planetesimal was likely structured with different layers — crust, mantle, core — just like Earth, he says, rather than being a homogenous chunk of rock, as scientists had thought was the case for most planetesimals.

So it looks like there is evidence that the possible early planet or planetesimals, the destruction of which may have resulted in some of the asteroids, may have been layered, similar to the earth (or a cake, onion, or Shrek). Layered enough to have a rotating molten core generating magnetic fields. This contrasts with thinking up to this point which had held that planet formation for these smaller solar system bodies was not as advanced, or structured. Beyond generating new questions (which is always good), this should further our understanding of early solar system formation.


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