Aliens have declared a no-fly zone around our solar system

There are no other suns, so the absence of light means it is very difficult to find other planets (as they are black against a black background).

We are limited by the speed of light, it would take a long time to get anywhere without 'new technology'

Ever since The Big Bang the universe has been expanding, this means that the distance between out solar system and another is constantly increasing. This expansion is occurring at such a rate that we will never be able to go fast enough to overcome the increasing distance.

We live in a simulation that ends at the edge of our solar system

Jupiter

Venus

Mercury

Mars

Saturn

Megingjord

Orion's

Van Allen

Tellurium

Saturn V

Cosmonaut Mutilater

Command Module

Committee Made

Constitutional Managment

Construction Mode

Flat Earthers

Discworldians

Pratchettites

Machiavellians

Global Citizens