[Drew68]

He then used that data and applied it to the number of known “exoplanets” in our galaxy, which Italian scientist Claudio Maccone estimated to be around 15,785.

Huh?

There's probably around a trillion exoplanets in our galaxy. We've already found about 5,000 of them and really, we've just started looking.

We find exoplanets around ever star we've looked for them at and we've looked at around 3,000 stars. A few hundred billion more to go! If exoplanets are the rule and not the exception, this number will be huge.

[Krosan]

I think this misconception might come from a once-popular book “Rare Earth” published in 2000. It based its whole logic on a premise that with current telescopes we haven’t seen many planets and that must mean planets are extremely rare.

It was already largely bunk at the time of publishing, but we have gotten better telescopes now and seen that planets are not rare. We just couldn’t see them with the old stuff.