Both versions were later released, by Saturn, in a double pack along with the sequel game Return to Earth. These were republished by Mikro-Gen.
Inlays, videos and/or downloads exist online to show that Mikro-Gen also released the double-pack for the Oric (16K or 48K), VIC20 (with 8K or 16K) and TI99/4A.
A version, copyrighted to Saturn Developments, exists for the C64. The port is credited to DJJWM of Newman Software. It's unclear if this version is official.
The C64 game (or potentially the VIC20 version) was unofficially remade by Brando Denicora as Saturn's 10 Moons and published by ICA (Italien Computer Adventures) in 1988.
[+] Users currently playing this game
"The game was later unofficially remade as Saturn's 10 Moons."
Why? It was already available for the C64 and it's not a particularly good game.
I haven't gotten the foggiest. But the remake is out there.
Fairly horrendous, but not at Mad Martha levels. At least this one tries to be an adventure.