It will be a symbolic step of life from Earth, leaving Earth, and growing somewhere else.

If you look at our own planet Earth, for half of its history, life was microscopic. It's the first step to more complicated life.

You just walk past to get somewhere else,

He had a charm about him sometimes, a warmth that was irresistible, like sunshine. He planted Saffy triumphantly on the pavement, opened the taxi door, slung in his bag, gave a huge film-star wave, called, "All right, Peter? Good weekend?" to the taxi driver, who knew him well and considered him a lovely man, and was free.
"Back to the hard life," he said to Peter, and stretched out his legs.
Back to the real life, he meant. The real world where there were no children lurking under tables, no wives wiping their noses on the ironing, no guinea pigs on the lawn, nor hamsters in the bedrooms, and no paper bags full of leaking tomato sandwiches.

She had to go," said Rose.
"It was because of her angel," said Indigo.
"And because of Granddad," added Caddy.
"And because of her nose stud."
"And because her name isn't on the color chart."
"She's lonely," said Rose. "That's why.

It's sort of a crime scene investigation. There was life here. ... We've got to pull that out.