Zodiac series, book 1

Rhoma Grace is a 16-year-old student from House Cancer with an unusual way of reading the stars. While her classmates use measurements to make accurate astrological predictions, she looks up at the night sky and makes up stories. When a violent blast strikes the moons of Cancer, sending its ocean planet off-kilter and killing thousands of citizens-including its beloved Guardian-Rho is more surprised than anyone when she is named the House's new l...