Mile-long spaceships, evil robots, galactic warlords with maniacal laughs, and slimy green aliens with four brains and six armpits. Don't be alarmed but we're not alone...
	The hitchhiker's guide to the galaxy by Douglas Adams (1979) First book in The hitchhiker's guide to the galaxy series
	Noughts and crosses by Malorie Blackman (2001) First book in the Noughts and crosses series
	Fahrenheit 451 by Ray Bradbury (1953)
	Ender's game by Orson Scott Card (1985) First book in the Ender Wiggin series
	Enchantress from the stars by Sylvia Engdahl (1970)
	Flowers for Algernon by Daniel Keyes (1966)
	The knife of never letting go by Partrick Ness (2008) First book in the Chaos walking series
	Z for Zachariah by Robert C. O'Brien (1974)
	Delirium by Lauren Oliver (2011) First book in the Delirium series
	The adoration of Jenna Fox by Mary E. Pearson (2008) First book in the Jenna Fox chronicles series
	Mortal engines by Philip Reeve (2001) First book in the Predator cities series
	Unwind by Neal Shusterman (2008) First book in the Unwind dystology series
	The war of the worlds by H.G. Wells (1898)
	The day of the triffids by John Wyndham (1951)
	The Midwich cuckoos by John Wyndham (1957)
	Ship breaker by Paolo Bacigalupi (2010) First book in the Ship breaker series
	Genesis by Bernard Beckett (2006)
	Across the universe by Beth Revis (2011) First book in the Across the universe series
	The 5th wave by Rick Yancey (2013) First book in The 5th wave series