Book Search: Kid travels to another world; adapts by collecting soil?

Question

Searching for a science fiction book about a young boy (preteen/teen) that travels to another world/planet (maybe multiple worlds). While he is on the planet(s) he collects a soil sample. Something about the soil was significant to the plot. Perhaps it allowed him to adapt to the environment of the new world, or maybe it transformed him physically to appear like the native species.

Unfortunately, I cannot remember any more detail. Every few years I decide I'm going to figure out what book this was, but after scouring lists of sci-fi book indexes, nothing jumps out at me. This is my first shot trying to use the public hive mind.

I would have read it some time between 1992-1996. I was in elementary school at the time and the book would have been age appropriate. I imagine it was a pretty short book, but I don't think it was considered a "short story." I think it stood on it's own, not as part of a collection. My dad checked it out from the library for me and it was one of my early exposures to science fiction.

If anyone has thoughts on this, I would be excited to hear them. Thanks!

Answer 1

The Wonderful Flight to the Mushroom Planet, by Eleanor Cameron.

From Wikipedia:

When two boys find an ad in a newspaper asking for two young boys to build a spaceship, they quickly construct one out of old tin and scrap wood, and bring it to the advertiser. This man is the mysterious Mr. Tyco Bass, an inventor and scientist. Using his marvelous stroboscopic polarizing filter he shows the boys a previously undetected satellite of the Earth, which he calls Basidium-X. He refits their spaceship, giving them some special fuel he invented to power it, and tells them to fly to the mushroom planet (after getting their parents' permission). He warns them that their trip will only be successful if they bring a mascot.

When it is time for launch, they grab David's hen, Mrs. Pennyfeather, at the last moment for a mascot, and rocket into space. They find the planet of Basidium to be a small, verdant world covered in soft moss and tree-size mushrooms. They quickly meet some residents of the mushroom planet, small men with large heads and slightly green skin, of the same people as the mysterious Mr. Bass. They tell the boys that their planet has had a crisis and that everyone is slowly dying of a mysterious sickness. The boys meet up with the king of the planet, the Great Ta, and end up solving the natives' problem, before returning to Earth.

Been searching a long time myself.

Answer 2

I believe you're looking for The Transall Saga by Gary Paulsen.