Hxen.com's tips：Every day persisted can learn English well!-->■Learn English Everyday■
solar system - n. our sun and the planets that move around it
galaxy - n. any of the very large groups of stars that makes up the universe
Milky Way - n. the galaxy in which we live that contains the stars that make up the Milky Way
data - n. facts or information used usually to calculate, analyze, or plan something
surge - n. a sudden large increase
intersect - v. to meet and cross at one or more points
instability - n. the state of being likely to change
density - n. the quality of having parts that are close together
