A planet isn't retrograde - retrograde means the direction a planet moves in relation to how we see it here on Earth or other perspectives. Planets sometimes appear to move backward due to Earth moving as well.
retrogade motion
Retrogade rotation
Short answer we don't know. But there are several theories, the best among them is that massive impacts or near misses during the formation of our solar system pushed the planets into the current orbits and rotations.
A dwarf planet it used to a be a planet
The planet that is nicknamed the 'sideways' planet is Uranus
Mercury.
retrogade motion
Valves
retrogade motion
Retrogade rotation
The retrogade motion of Mars happens because Mars is slower than Earth and occasionally we overtake it, so it appears to move backwards.
Short answer we don't know. But there are several theories, the best among them is that massive impacts or near misses during the formation of our solar system pushed the planets into the current orbits and rotations.
It is Venus , the nearest planet to our planet .
There is no planet which has a natural planet.
The planet that was an outer planet, but was more like an inner planet was Pluto because of its size. The planet Pluto is no longer considered to be a planet.
There is no planet that is called the "glossy planet".
A dwarf planet it used to a be a planet