This is what I watched when I was growing up (it came out in the late 70s, so it was already around for a while by then though): Schoolhouse Rock, Interplanet Janet [0]. This is really how I knew the planets growing up. "Mars is red, and Jupiter's big, and saturn shows off its riiiiings, uranus is built on a funny tilt, and neptune is its twiiin, and pluto little pluto is the furthest planet from the suuuun, whoo hoooo"
When my brother was growing up (around 2001, so I was 11 at that point), they had this song [1]. Kind of jazzy and relaxing. It went over the planets a few times in the verses, slowly taking the time to walk the children through it, and the way Nick Jr worked back in the day, the same episode would be on 3-4 times in a row every day, so the kid could really take it in. I could recite it from my head to this day.
A couple years later (2005) you start getting songs like this [2], I'm glad I didn't have to rely on this for memorizing the planets? Still, it's only a minute long, I think this is when kids started to hit lower attention spans.
I was trying to see what kids have these days. Since I'm basically seeing children as early as 5-6 months given an iphone/ipad to watch youtube, I figured I'd start there.... 99% of children's programming online is really crappy garbage shovelled out for dirt cheap with usually disturbing imagery subliminally thrown in. For example, this video [3] (I couldn't get through all three minutes, it was too monotone, repetitive, and the mouths on still frame were buttholes)
Jumping away from YouTube (originated content), I did find a shorter video by "Netflix Jr." [4]. It came recommended by reddit parents. Fastpaced rapping, jumping around, but not badly animated but I do wonder if children would grasp all of the concepts from it.
Trying to find the latest one that came out, was this [5] that wasn't hard for me to get through like the second-to-the last one (and hey it mentioned pluto lol)
[0] https://www.youtube.com/watch?v=MGgajx1pGPU
[1] https://www.youtube.com/watch?v=zA8olJuyTyc
[2] https://www.youtube.com/watch?v=qgGbOrz3Bqk
[3] https://www.youtube.com/watch?v=mQrlgH97v94