What's the Name of That Book??? discussion

Read maybe between 2000-2005.

Science fiction book about this spaceship humans found orbiting somewhere. They board this ship that is like the size of a small state. It has this whole environment and ecosystem with plants and water. And as they are on it the whole system changes and crazy things happen.

@kiki this is a pretty generic description as such a theme is pretty common in SF. Any additional details you can provide such as whether you think this was an older book (even though you read in 2000-2005), any descriptions of the plants you may recall. Was the crew from one country? Many countries? All men? All women,? Mixed crew?

However, as a first guess I might suggest checking out: Rendezvous with Rama by Arthur C. Clarke.

"At first, only a few things are known about the celestial object that astronomers dub Rama. It is huge, weighing more than ten trillion tons. And it is hurtling through the solar system at an inconceivable speed. Then a space probe confirms the unthinkable: Rama is no natural object. It is, incredibly, an interstellar spacecraft. Space explorers and planet-bound scientists alike prepare for mankind's first encounter with alien intelligence. It will kindle their wildest dreams... and fan their darkest fears. For no one knows who the Ramans are or why they have come. And now the moment of rendezvous awaits — just behind a Raman airlock door."

Hi Brad!
YES! That's it!!! Thank you so much! It's been driving me nuts!

Glad I was able to help with this. You may already be aware but if you did enjoy the first book you may be pleased to learn that it is actually a series. The other books include:

Rama II
The Garden of Rama
Rama Revealed

Happy reading :-)