So I was watching an American docu about our Solar System and how our concept of it has changed radically in the last forty years.
Pluto got downgraded to 'dwarf planet' status because there are supposedly hundred of Plutonic objects out in the Kuiper Belt - we couldn't see them until recently.
Then there is the Heliosphere, Heliopause and Bow Shock protecting us from cosmic rays pumped out by nearby stars. I get all that.
Further out is the Oort Cloud where the comets live in eccentric orbits. Why do some of them decide to dive in toward the Sun, accelerating to 100 miles per second?
The astrophysicists reckon there is a large object out there disturbing the paths of the comets, called Nemesis. Is it a brown dwarf, or a gas giant?
Or is our own Oort Cloud disturbed by the Oort cloud of Alpha Centauri?
I bloody love space!