This is a story of two very strange meteorites, one strange because of its bizarre differences
to anything else we’ve ever seen in meteorites, and one that is bizarre because of its eerie
similarity to something we most definitely have seen.
The first of these is the so-called Hypatia stone.
It was found in 1996, and seemingly associated with a unique apparently impact related yellow
glass, the Libyan Desert Glass, that is found in the same area of the Sahara desert.
This meteorite is thought to have originated when the nucleus of a comet impacted earth
about 28 million years ago.
But it soon became apparent that part of this material was extremely primitive, even for
material from a comet, so much so that it may predate the formation of our solar system.
Chemically, parts of the meteorite are very unlike the general makeup of our solar system.
For example, the meteorite has high levels of carbon, but very low levels of silicon
compared to the makeup of a typical asteroid, or earth, essentially opposite so.
The carbon compounds themselves in the meteorite are also unusual, called polyaromatic hydrocarbons,
these tend to be more associated with interstellar dust rather than solar system objects.
Another weird aspect of the meteorite is that it contains metal inclusions that include
things like metallic aluminum which in that form is extremely rare in the solar system.
While far from rare, most aluminum in the solar system occurs in compounds and locked
up ores.
Other chemical oddities in the stone include an association of nickel and phosphorus, with
very little iron, unlike normal meteorites where nickel and iron go hand in hand.
Much of the meteorite however isn’t like this, only parts of it, presumably because
the material collected together when the object formed, some of it from the solar nebula,
and some of it possibly dating from before the solar system formed.
All that’s really known about its formation is that the environment was cold, -196 celsius,
and could represent extrasolar material that was incorporated into the matrix of the meteorite.
But it could also be that the material represents some unknown differentiation in the early
solar nebula.
The other strange meteorite is the exact opposite of the Hypatia stone.Cataloged as NWA 5400,
this meteorite isn’t noteworthy for how strange it is, but how familiar.
While it’s exact origins can’t be pinned down definitively, while it’s certainly
a meteorite, oxygen isotopes found in this meteorite are very similar to the earth-moon
system, eerily so.
This could mean it has three possible origins.
It may just be chance, and that it’s from a parent body asteroid that just happens to
have similar isotope ratios to the moon and Earth, maybe it formed nearby.
Another possibility is that it’s a primitive rock from earth blasted off during the impact
that formed the moon, or at some other time, that wandered the solar system for billions
of years before returning home.
The third possibility is perhaps the most interesting, in that the rock might have originated
on Theia, the roughly Mars sized object that smacked into proto earth in a glancing blow
knocking the material off that would eventually form the moon.
There are problems with all three possibilities, one model of Theia suggests that it was probably
mostly ice having originated out around the frost line in the solar system, but this is
not known for certain.
But regardless, this is one strange meteorite, and it opens up the possibility that as we
explore the solar system, and find more meteorites here on earth, we might find pieces of earth’s
early history floating around in the solar system revealing information about our world,
evidence of which long ago weathered away or disappeared down here, or we might find
out information about the formation of other planets such as Venus and Mars when they were
in a much more primitive, and perhaps even habitable state.
And, as always, there is the possibility that studying such meteorites might also reveal
clues about panspermia, the idea that bodies in the solar system could have exchanged materials
that preserved life, and seeded it to multiple bodies in the solar system.
It’s even possible that early life on earth may not have originated here, but rather Mars.
While that’s speculation, the study of meteorites gives us a unique sampling of asteroids, comets
and objects across our solar system’s history.
And, with all of this talk about interstellar objects as of late, we might learn hands on
about distant planets in the milky way from the comfort of home.
Thanks for listening!
I am futurist and science fiction author John Michael Godier currently eyeing the universe
suspiciously for throwing rocks at us.
There was even one that fell in New York and took out a parked Chevy Malibu back in 1992.
How do you explain that to an insurance company, think I’ll pull the Lebaron in the garage
tonight and be sure to check out my books at your favorite online book retailer and
subscribe to my channel for regular, in-depth explorations into the interesting, weird and
unknown aspects of this amazing universe in which we live.