A cult soviet classic that is cherished by lots of people, especially those who grew up with it. Although made in 1981 it still looks excellent. It's by far the best sci-fi cartoon out of the Soviet Union that has everything in it: exciting adventures, space travel, strange creatures, space pirates, suspense, excellent animation, great music and a brilliant story.
The story is based on one of the books by Kir Bulychev, a sci-fi writer, who wrote a whole series about Alice's adventures. Some of them were translated into English. And because it's based on book and a script that is written by the same writer the story is solid, so that even adults find it interesting. There are common characters in all of these stories and the central one is Alice, a little girl whose father, professor Seleznev, is a biologist working for a zoo. And since it's 22-d century and many distant star systems have been explored and space travel became very common, the zoo is filled with space animals from other planets and so Alice gets to fly with her father once in a while to explore unknown worlds - this time in search for rare animals. Another common characters across the books are space pirates that are always up to something bad and Alice, being a curious girl, always getting into some sort of dangerous adventure. Kids of the future are very advanced intellectually and physically, and so Alice is already doing some scientific research in some of the stories. I guess that's one of the things that draw kids to these stories.
A few words about the English versions of the film and where to find them. Original Russian version with English subtitles that are not particularly well translated and of poor video quality is available on YouTube http://youtu.be/cTxIp_pMOk4. There is also a dubbed English bootleg US version called Mystery of the third planet (dollar store version) 1987, which retained the full video and music but with some significantly altered dialogues and added narrative which are not original - it is still watchable. http://youtu.be/NWTPMCD3SeQ. I have a review of that. There is also a third version of the cartoon called Alice and the Mystery of The Third Planet (1995), another US bootleg dubbed version. This one had the original music and sound all removed, 8 minutes cut out from the beginning of the film and a new narrative added. The dialogues, however, are nearly identical to the original, which is the only good thing about this version. It's also available on YouTube http://youtu.be/3lEoewc7Yns. This is also watchable but I wouldn't recommend any of the two bootleg versions. I'm hoping to get a new subtitled English translation on YouTube soon in HD quality so check back soon.