Mars in fiction from red-colored vegetation, and Schiaparelli observed what he took to be linear features on the face of Mars, which he thought might be water channels. Because the Italian for channels is "canali", English translations tended to render the word as "canals", implying artificial construction. Lowell's books on Mars expanded on this notion of Martian canals, and a standard model of Mars as a drying, cooling, dying world was established. It was frequently speculated that ancient Martian civilizations had constructed irrigation works that spanned the planet in an attempt at saving their dying world. This concept spawned a large number of
Colonization of Mars protect astronauts and spacecraft from radiation. In September 2017, NASA reported radiation levels on the surface of the planet Mars were temporarily doubled, and were associated with an aurora 25-times brighter than any observed earlier, due to a massive, and unexpected, solar storm in the middle of the month. Mars requires less energy per unit mass (delta V) to reach from Earth than any planet except Venus. Using a Hohmann transfer orbit, a trip to Mars requires approximately nine months in space. Modified transfer trajectories that cut the travel time down to four to seven months in space are possible