Tag Archives: tanka

Finally got to see fireworks

ROAR! Concussion–chest

and ears–a primal echo–

thousand tongues of flame,

magnesium-bright stars fall

to oohs and ahhs and silence.

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Filed under Poetry

Star stuff

meteorites

 

brilliant fiery streaks-

burning debris from solar

system formation.

truth is, falling stars aren’t stars

but lost cousins coming home.

 

 

Meteorites are natural objects composed of stone, metal, or a combination of the two that have survived their fall from space through our atmosphere. Most meteorites come from asteroids, a small percentage from Mars and the moon, a very few may even originate from comets.

 

Those that come from asteroids are the oldest objects that are available for direct study. (As opposed to the light from ancient stars, which we can see but not touch…) They date back about 4.5 billion years, to the first stages of the creation of the solar system. So they can give scientists insight into the processes that made our sun and its planets.

 

(FYI- Asteroids are not exploded planets, they’re the bits that never made it into planets, possibly because Jupiter’s gravitational pull was too strong for them to coalesce.)

Stone meteorites are mostly silicate rock very much like Earth’s crust. Iron meteorites are actually iron with different percentages of nickel. The stony-iron meteorites are just that. Though what’s really neat is that some have crystals of the gemstone peridot (or olivine) in them. So when you see a sample it’s this literally space age slice of metal with green gems embedded in it.

 

Just to confuse things–meteors–the ones you see in showers and normally are associated with the orbits of comets–don’t generally become meteorites. It’s very rare for there to be enough material to be recovered, the norm is complete vaporization.

 

Meteorites start as larger objects, called meteoroids. One would be travelling at around 67,500 mph when it hits our atmosphere and is slowed by the friction. The outer part melts off and the droplets are carried away–at this point, though slowed by the atmosphere it is still moving fast enough to create shock waves. As it cools and falls the melted surface forms a glassy coating known as a fusion crust. Once it (or its pieces if it explodes in the air) hit the ground it’s officially a meteorite.

 

Factoids:

 

40,000-60,000 tons of ‘extraterrestrial material’ fall to Earth every year. Most are almost dust grains, smaller than 1 mm.

 

Around a thousand meteorites bigger than a soccer ball strike the Earth’s atmosphere every day.

 

Yes, people have been hit by meteorites… I wonder if insurance covers that?

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Filed under Gems, Natural Science

Fossil Echoes

nature, she echoes

variation on a theme

of fractal design

changed over millennia

past fossils like growing leaves

 

Brachiopods (literally arm-foot) appeared at the beginning of the Cambrian and peaked during the Ordovician (490-445 mya).

What’s fascinating is that while most of them have gone extinct, some species of brachiopod are still around, so it’s a story of survival. Even though I’m working with fossils of creatures that died hundreds of millions of years ago, a number of their descendants and cousins are still on sea floors the world over. (Around 100 different genera still exist, over 5000 are known to have existed.)

Brachiopods are bottom feeding marine creatures with two shells. (You can see the lip of their joint nicely in the fossils I picked up.) They’re symmetrical when viewed from above, unlike bivalves.

Mine are members of the spiriferidia. I think they’re of the Mucrospirifer genus. Some of the rock hounds on deviantart are thinking along the same lines, but I don’t have a location of origin to narrow matters down.

The one I bought more recently was from southwest Ontario and identified as a Mucrospirifer thedfordensis from the mid Devonian. (That’s about 385 million years ago.) My previous stash were probably from the same general area. (I’ve been told New York State is another possible origin.) This genus reached its highest levels of number and diversity during this period, so it’s a probably a safe guess that all the ones I’ve worked with are all (loosely!) around the same age.

I’m not sure all of my original stash were of the same species to begin with; since some were chubbier like the thedfordensis and others were much slimmer, though they all share the same basic shape and nice curve. I don’t know how much variation existed between individuals of a species.

Mucrospirifer thedfordensis

(I’m not very good at identifying fossils beyond the general. Anyone know of a good, *simple* guide for fossils? I like playing with ammonites too but can never divide them into species either.)

They would have lived in soft mud on the sea floor and attached to the bottom with a fleshy stalk. They were found all over the world. Brachiopods took a hit at the end of the Devonian period, but a diverse number survived into the next hundred million years. A lot of brachiopod species went extinct during the Permian Mass Extinction ( about 251 mya), along with a lot of the other ‘classic’ species we’re familiar with–like the trilobites. The corals of the era were so badly destroyed it took over 10 million years for them to recover, and 150 million for biodiversity to bounce back to pre-extinction levels. (Some of the Mucrospirifers survived the Permian Mass Extinction and held on into the Jurassic period.)

Walking past the brachiopods on a dealer’s table en masse they reminded me of fallen ginkgo leaves. I decided that I had to play with that resemblance by wrapping them with ‘stems.’ Now I want more to experiment with, and to learn how to properly identify the little suckers. I’d really like to take the term butterfly shells literally and do a butterfly shaped wrap somehow.

(Yes, I wrote a tanka over a fossil, I wrote a few about different types actually…)

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Filed under Crafts, Natural Science