[sniggers]

IANAPNA either, but a solid object like a planet blocks light differently than dust clouds. Dust clouds, even dense ones, still allow some wavelengths through that planets do not. I would guess that's what allows them to be confident that it's a planet.

[hackable_sand]

Huh...

I just realized I can start using IANA phonetically as a word.

Iana

I like that