The meteor shower ran from the Gobi, past the Arabian and Sinai, then clear through the Sahara.  Micrometeors buried themselves in the desert sands.  Not one struck road or oasis or city.

Hours later, more hit the mosaic of deserts that stretched down the American Southwest into Mexico. The Australian Outback came next, straight to South Africa.  Both strikes followed the same pattern.

Buried in a letter to the editor of a mid-major newspaper, someone noted that these were the deserts most visible from space.

From the points of impact, plant-life sprang forth.

Once the deserts had bloomed, alien insects came out of the ground.  The micrometeors had been eggs and seeds.

A symbiosis began, plant and bug each nourishing the other.

Curious people went into the new growth.  But these new lifeforms were extremophiles.  The merest touch was acidic.

People learned to stay away.

That’s when the spacecraft landed.