Millbillillie

[David Entwistle]

Manchester Museum's Millbillillie 14.4 g slice, purchased at the Tucson show in 1999.

N15104

Name: Millbillillie
This is an OFFICIAL meteorite name.
Abbreviation: There is no official abbreviation for this meteorite.
Observed fall: Yes
Year fell: 1960
Country: Australia

Classification: Eucrite-mmict

[David Entwistle]

[Corrections and additions welcomed to this bit... ]

As I understand it, the classification (Eucrite-mmict) shows that Millbillillie originated from a solar system body (possibly the minor planet Vesta) large enough to form a molten core, and for long enough to allow an iron core to separate from magma formed from molten rock. Being heavy, the iron core settled to the centre of the body, and the lighter magma floated around it in a process know as differentiation. It was the magma bit that then cooled and became the rock that forms the Eucrite meteorites. It was a chunk of this rock that was ejected during a subsequent impact and spent an age orbiting the Sun before crashing to Earth, in the case of Millbillillie, in 1960.

So, the Eucrites look similar to the basalt rocks that form in a similar way on Earth.

[msg-meteorites]

Sounds right to me David

A pretty neat succinct summing up of the process

Cheers

Martin

[David Entwistle]

A pretty neat succinct summing up of the process

Thanks Martin.

I have to say the Millbillillie slice doesn't look like a typical terrestrial basalt to me - it's got a coarser grain than the basalts I've seen, but I guess there's a lot more to a basalt than its appearance.

A quick search of NASA ADS suggests The eucrite / Vesta story, by Michael J Drake, as suitable source of further reading for anyone interested in getting a bit more detail.