Author Question: ____ are crucial in determining the distance to objects that are far away, but still in the Milky ... (Read 58 times)

Evvie72 · **on:** Jul 27, 2018

____ are crucial in determining the distance to objects that are far away, but still in the Milky Way galaxy.

a. RR Lyrae stars
b. Cepheid variable stars
c. O and B stars
d. Emission nebulae
e. Supernovae

Question 2

Perigee is the point in ____.

a. the Moon's orbit when the Moon is farthest from Earth
b. an object's orbit around Earth when the object is closest to Earth
c. an object's orbit around Earth when the object is closest to the Sun
d. a planet's orbit when the planet is closest to its sun
e. a planet's orbit when the planet is farthest from its sun