On 10/12/2015 9:03 AM, dlzc wrote:
How many solar systems have we investigated, such that we would know
the makeup of crustal elements of small rocky bodies?

I find it naive to be surprised here. We have to crank our various
empirical engines to make predictions, with insufficient data for
building them. I know it is "something to do" while waiting for
interstellar travel to become a reality, but...

David A. Smith

I don't think it's really the geology that's at issue here, rather the
chemistry. Specifically the isotopic chemistry. They mentioned the one
thing in this article about Plutonium-244. Their models don't show this
isotope being produced in normal supernova explosions, but they believe
it can be produced in neutron star-neutron star collisions.

Here's an earlier report, where a different team doing similar analysis,
except this time tracing Iron-58 and Iron-60 in meteorites, came to a
different conclusion, that we weren't produced in a supernova explosion.

Our Solar System Formed From The Cumulative Ashes Of Countless Stars,
Not One Supernova | Popular Science
http://www.popsci.com/science/articl...ova-study-says

So which report to believe? Not sure, too much detective work involved.

Yousuf Khan