'There were scores of the big flowers, in various stages of unfolding. Now, they reminded me of butterflies, just emerging from the chrysalis... wings crumpled, still feeble... I was getting closer and closer to the truth.

'But they were freezing – dying as quickly as they formed. Then, one after another, they dropped off from the parent buds. For a few moments they flopped around like fish stranded on dry land – and at last I realized exactly what they were. Those membranes weren't petals – they were fins, or their equivalent. This was the free-swimming, larval stage of the creature. Probably it spends much of its life rooted on the seabed, then sends these mobile offspring in search of new territory. Just like the corals of Earth's oceans.

'I knelt down to get a closer look at one of the little creatures. The beautiful colours were fading now, to a drab brown. Some of the petal-fins had snapped off, becoming brittle shards as they froze. But it was still moving feebly, and as I approached it tried to avoid me. I wondered how it sensed my presence.

'Then I noticed that the stamens – as I'd called them – all carried bright blue dots at their tips. They looked like tiny star sapphires – or the blue eyes along the mantle of a scallop – aware of light, but unable to form true images. As I watched, the vivid blue faded, the sapphires became dull, ordinary stones...

'Dr Floyd – or anyone else who is listening – I haven't much more time – Jupiter will soon block my signal. But I've almost finished.

'I knew then what I had to do. The cable to that thousand-watt lamp was hanging almost to the ground. I gave it a few tugs, and the light went out in a shower of sparks.