How did scientists determine an estimate of the number of planets greater than Sedna's size to exist in the Inner Oort Cloud?
In the article, New Dwarf Planet Found at Solar System's Edge, Hints at Possible Faraway 'Planet X' (Wall, 2014) where they report on research and observations performed by astronomers that discovered ...
Do all stars have an oort cloud like ours that will be filled with comets and other objects? If not, why are they not around every star?
Considering their distance from their parent stars, might Oort cloud object such as comets be exchanged between passing stars (assuming that other stars have similar Oort clouds)?