Ten Billion to One

We've found more than six thousand planets around other stars, and almost none of them have we ever actually seen. We know them the way you'd know someone from a fingerprint rather than a face: their masses, their orbits, the length of their years, all inferred from the way a star wobbles or dims. The one picture we want most, a world like Earth around a star like the Sun, close enough to read its air for signs of life, doesn't exist — and not because our telescopes are too small. It comes down to a single ratio, ten billion to one, the glare of a star set against the faint planet beside it. This first episode is about that ratio, and about the fork it forces on everyone who tries to beat it: to block a star's overwhelming light, do you do it inside your telescope, or out in the dark, far in front of it?