Whether a speck of dust is man-made or natural can be worked out from its trajectory.

ECONOMIST: Orbital debris

The capsules are made in ultra-clean conditions a speck of dust could ruin the effect.

ECONOMIST: Germany's export champions

Physically, the DNA carrying all that information is no bigger than a speck of dust.

BBC: DNA 'perfect for digital storage'

But the DNA was there it lay like a speck of dust at the bottom of the vial, almost impossible to see.

WSJ: Scientists Store King Speech, Shakespeare Sonnets in DNA