More Life’s Coming #Alien #space #star #life #poem #poetry

Stromatolites

Pre-Cambrian fossil, 3.5 billion years old, but reminds me of a starry sky by Van Gough. Thanks to the US National Park Service

Life arose on Earth
In conditions fairly rare,
Yet as the universe matures
Life could be everywhere.

With star formation winding down,
Supernovae will dwindle,
Small dim stars proliferate,
More room for life to wiggle.

Impatient were our ancestors
Or maybe we’re just lucky
Self-replicating molecules
Simply weren’t too fussy.

Earth may be a pioneer
With most life future-tense,
Good news for astrobiologists
Five billion years hence.

By Kate Rauner

My schedule got away from me this week, so I’m posting my weekly poem late. I hope it’s worth the wait, and my thanks to smithsonianmag.com

#Life is Made of #Comet s – a #poem by Kate Rauner

Rosetta's_Philae_touchdown

Artist’s concept of Philae’s touchdown on Comet 67/P

A – ce – ta – mides,
Pro – pi – on – al – dehydes,
That’s what the spectrum’s made of.

Snips and snails
And puppy-dog tails,
That’s what boys are made of.

Ice and dust
And organic musts,
That’s what comets are made of.

Sugar and spice
And everything nice,
That’s what girls are made of

Brought to Earth
Eons ago
That’s what life is made of.

Thanks to Wikipedia for versions of the 19th century nursery rhyme. And to Rosetta , the first spacecraft to orbit a comet; to Philae, the first to achieve an almost-soft landing on one; and the “sexiest mass spectrum” ever for what comets are made of. [nationalgeographic.com]

Plate Tectonics, Life, and Luck

Opabinia from the Burgess Shale

Opabinia from the Burgess Shale

The Earth formed four and a half billion years ago and after a billion years of cooling the crust solidified and life appeared. Earth has been inhabited for most of its existence, but only five hundred million years ago does anything more complex than microbial mats and cyanobacteria appear in the fossil record. Then all the basic body plans that exist today evolved so quickly (in a geological sense of time) that the era is called the Cambrian Explosion. After three billion years of stasis, what changed?

Maybe the earth moved.

Repeatedly, the continents on Earth have clustered together into a single supercontinent, leaving a single superocean. Once again, about five hundred million years ago, tectonic forces broke a huge slab of continent off, creating a shallow ocean in warm equatorial latitudes while dredging up nutrients from deeper waters. The continents have merged and broken apart cyclically over geologic time, but this event was a perfect evolutionary opportunity. Life exploded in an orgy of multicellular diversity.

It’s the sort of unlikely situation that leads to thoughts that, even if life is common in the galaxy, complex life and especially intelligent life may be vanishingly rare. But plate tectonics seem to be related to planetary mass, so any rocky planet Earth-sized or larger may offer life the same chance. Just add water.

Read about the study by Ian Dalziel of the University of Texas Institute for Geophysics, published in the November issue of the journal Geology.