1fa1dd55__Ion_Propulsion___Dawn_Mission__Grades_9_12
[Grades 5-8] Physical Science Properties of matter A substance has characteristic properties, such as density. [Dawn Instrumentation Module] Doppler shifts in radio waves are used to determine differences in mass concentration (i.e. density) in Ceres and Vesta [Grades 9-12] 
Physical Science
Education > Structure and Properties of Matter: Ion Propulsion | Dawn Mission
Grades 9-12