How do we know that there are intergalactic clouds between a distant quasar and us?
A) We see hydrogen emission lines at redshifts smaller than that of the quasar.
B) We see hydrogen absorption lines at redshifts smaller than that of the quasar.
C) We see hydrogen emission lines at redshifts greater than that of the quasar.
D) We see hydrogen absorption lines at redshifts greater than that of the quasar.
E) We see that the emission lines from the quasar are lessened by intervening gas and dust.
Question 2
According to Gwen back on Earth, about how long does it take Jackie to reach Vega?
A) about a month
B) about 10 years
C) about 25 years
D) about 100 years
E) about 1,000 years
Mammatus clouds
Dimmer Distant Supernova
Cloud Types: Low Clouds
Quasar
E chart for testing distant vision
Classification of Clouds According to Height and Form