One day late last year, Dave Lavery - a roboticist who works for NASA and is currently on the Mars rover project - visited my university to give a talk. Before the event itself, he had kind of an informal conversation with some of the PhD students lying around the department.

I was sitting quietly in the corner of the Physics Department's Multi-Purpose Room (a combined seminar theatre, kitchen, event hall and, at that point in time, my surrogate office), working on my holiday project, and my supervisor asked me if I'd like to sit in. I'm very glad that I did - he was a fascinating person to listen to and had several entertaining anecdotes in his back pocket. One of these inspired the following.

By NASA/JPL/DLR [Public domain], via Wikimedia Commons

Some kind of trout

Lachlan Marnoch, 2018

The fish was minding her own business when a fissure opened in the ice above and she was sucked unceremoniously upward.

She wasn’t really a fish, of course. But she had fins, she had gills, and her shape was ideal for slicing through Europa’s subsurface oceans. The obvious difference, biochemistry aside, was her lack of eyes, and some deep-water Earth fish don’t have those anyway.

The rising current, drawn by the fissure’s opening, cared little for her taxonomic status as it propelled her through the ice. Battered against kilometres of frozen crust, she was finally blasted abruptly into space. Quite blind, she had no way to appreciate the grandeur of the moons wheeling about Jupiter’s furious visage, or of her smooth homeworld retreating below her - the offending cryovolcano already sealing itself over. Instead, the sudden vacuum induced violent decompression, heat leaked slowly from her body, and her gills flapped uselessly for absent water. She died wishing dearly for the pleasant warmth of the moon’s equatorial currents.

The fish’s frozen corpse tumbled into a Jovian orbit. Wrenched this way and that by the whims of the moons, thawed and refrozen by the radiation belts, she continued her unwilling voyage for years. Until, one day, SPLAT.

The pilot of the first manned flight to Jupiter blinked at the alien remains embedded in her front window. She turned to her co-pilot, his eyes as wide as hers.

Their transmission reached Earth forty-two point five minutes later. It was relayed from the Guizhou radiotelescope to Darwin Spaceflight Centre, then broadcast live for the whole world to hear:

“Uh, Darwin… we appear to have collided with some kind of trout. Please advise.”