The cosmic microwave background is:
A) redshifted in the direction of Earth's motion.
B) redshifted in the direction of the Sun's motion.
C) redshifted in the direction of the center of the Milky Way.
D) blueshifted in the direction of Earth's motion.
E) blueshifted in the direction of the Virgo Cluster.
Question 2
If the Sun were replaced by a one solar mass black hole:
A) all terrestrial planets would fall in immediately.
B) we would still orbit it in a period of one year.
C) we would immediately escape into deep space, driven out by its radiation.
D) our clocks would all stop.
E) life here would be unchanged.
Mira as seen from the Earth
Size comparison of Earth and Uranus
Comparative sizes of the Earth and the Moon
Earth’s history spans 4.5 billion years. Geologists and paleontologists have pieced together the his
Obliquity "Tilt of Earth on its axis"
The Oceans of Earth