Teachers and parents, here's something your kids might enjoy.
Paxi - the Red Planet is a little video in which Paxi isn't a little green man from Mars, but a space alien that ends up on Mars. It's made by ESA (European Space Agency). It gives some facts about Mars and Mars exploration without getting technical or being overly long.
But Paxi does have a British accent, so I don't know if that would be a problem for North American children. You can turn on captioning, but it's so awful that I blush with embarrassment on ESA's behalf. No one would understand the video from that. A few examples, with caption words followed by what was actually said.
I'm Pike see I'm PaxiMy spaceship glad keep navigation system My spaceship galactic navigation systemI'm lost without it there's a positive ahead I'm lost without it. Look. There's a planet up aheadI hope they're friendly ice at the polls I hope they're friendly. There's ice at the poles