The Oort cloud is a huge region of icy objects surrounding our Sun. We're not sure it exists, but we think it's where comets come from.
I've often seen the Oort cloud drawn as a vague round blob. But recently some people simulated it - and discovered that tidal forces from the Milky Way may pull it into a much more interesting shape!
It actually looks like a cartoon of a galaxy! But it's poking up at right angles to the plane of our galaxy, drawn in blue here. The red line is the plane that the planets mostly move in, called the 'ecliptic'.
According to our theories, the Oort cloud formed about 4.6 billion years ago when the Solar System was young. As the outer planets cleared their orbital neighborhood, billions of small icy objects were pushed into very eccentric orbits that come as close as 30 AU to the Sun and then shoot out as far as 1000 AU. (Remember, the Earth is 1 AU from the Sun.) Later, Galactic tidal forces slowly pulled these objects farther from the Sun and tilted their orbits. Encounters with nearby stars tend to randomize the orbits of these Oort cloud objects.
By now, the inner Oort cloud consists of objects 1000 to 10,000 AU from the Sun. It's more or less flat, roughly 15,000 AU across, tilted 30° to the ecliptic, and it looks like a spiral with two twisted arms.
The spiral structure was first noticed when they showed this simulation in the Hayden Planetarium in preparation for a new space show!
Physicists like to start by "assuming a spherical cow". But when they study something in detail, it's usually more complex. Even black holes usually have a disk, with jets shooting out.
The paper is free here:
https://iopscience.iop.org/article/10.3847/1538-4357/adbf9b