How did I miss these three last year? Jules Verne was a French author who was an early proponent of the science fiction genre because he was writing about air, sea and underwater travel long before modes of transport had been invented to do this. His exciting novels are certainly not written for eight year olds but when you see versions of Eighty Days Around the World like the Usborne Reading one you can understand why eight year olds are devouring them.
American author illustrator Anne Rockwell has written and illustrated many books, but I think she is at her best when she does non-fiction books for very young readers. Her series about transport: Trains; Bikes: Big Wheels; Planes; Boats etc are ideal for preschoolers especially when they are accompanied by books that include photographs. Her newer titles about the environment which are part of the Let's Read About Science series also have a place in classroom unit libraries. See Why Are the Ice Caps Melting? and What's So Bad About Gasoline?
And thirdly, English author Malorie Blackman. She is an award winning writer of novels for adolescents. Her novels tackle some tough issues and challenging subjects. But, it is possible to introduce younger children to Malorie Blackman's writing. She has done written several bridging novels for series such as Corgi Pups, the Whizziwig series and several picture books.