Glossary

A

B

C

D

E

F

G

H

I

J

K

L

M

N

O

P

Q

R

S

T

U

V

W

X

Y

Z

H

Hydrogen

element consisting of one electron and one proton
lightest of the elements
building block of the universe
stars form from massive clouds of hydrogen gas

Hubble's Law

law of physics that the farther a galaxy is from us, the faster it is moving away from us

Hypergalaxy

system consisting of a spiral galaxy surrounded by several dwarf white galaxies, often ellipticals