MarsX: A Novel Remembered Earth Universe Book 4 We will colonize Mars, just not in the way we think. The decision will be made for us. And out of desperation we will meet the challenge. But this staggering undertaking is only the beginning. Set in the author's Remembered Earth Universe, a collection of short stories, novellas, and novels extrapolating man's move into the Solar System, MarsX is not your ordinary kind of Mars colonization story. Note: Originally published as the novellas MarsX1, MarsX2, MarsX3. See the author's website for more information. Hard Science Fiction - Old School.