Pluto’s atmosphere has been studied since the 1980s, using spectroscopy and stellar occultation (watching starlight flicker as Pluto passed in front of it). It wasn’t a surprise when New Horizons observed it.
I wasn’t thinking about the atmosphere. I meant in general, Pluto surprised more than other first fly-bys. Uranus is obviously extra weird in a lot of ways but who was expecting Pluto to be as interesting?
Short answer? Because it does. It doesn’t take much to be visible compared to space.
I don’t think any planet1 has surprised us more than Pluto.
1 I know. If anyone gets pedantic, they’re reclassified as a dwarf clown.
Pluto’s atmosphere has been studied since the 1980s, using spectroscopy and stellar occultation (watching starlight flicker as Pluto passed in front of it). It wasn’t a surprise when New Horizons observed it.
I wasn’t thinking about the atmosphere. I meant in general, Pluto surprised more than other first fly-bys. Uranus is obviously extra weird in a lot of ways but who was expecting Pluto to be as interesting?
Oh wow that’s really cool! I didn’t know.
It’s about one millionth of the pressure of earth’s atmosphere at sea level.