20: Between the Stars - Gas and Dust in Space

Question 1

the cycling of mass in and out of the interstellar medium, including accretion of gas from intergalactic space, loss of gas back into intergalactic space, and conversion of interstellar gas into stars

Answer 1

baryon cycle

Question 2

atomic nuclei (mostly protons) and electrons that are observed to strike Earth’s atmosphere with exceedingly high energies

Answer 2

cosmic rays

Question 3

the region of ionized hydrogen in interstellar space

Answer 3

H II region

Question 4

tiny solid grains in interstellar space thought to consist of a core of rocklike material (silicates) or graphite surrounded by a mantle of ices; water, methane, and ammonia are probably the most abundant ices

Answer 4

interstellar dust

Question 5

the attenuation or absorption of light by dust in the interstellar medium

Answer 5

interstellar extinction

Question 6

the gas and dust between the stars in a galaxy (interstellar matter)

Answer 6

interstellar medium (ISM)

Question 7

a region of low-density, million degree gas in which the Sun and solar system are currently located

Answer 7

Local Bubble

Question 8

a slightly denser cloud inside the Local Bubble, inside which the Sun also lies

Answer 8

Local Fluff

Question 9

a large, dense, cold interstellar cloud - because of its size and density, this type of cloud can keep ultraviolet radiation from reaching its interior, where molecules are able to form

Answer 9

molecular cloud

Question 10

a cloud of interstellar gas or dust - the term is most often used for clouds that are seen to glow with visible light or infrared

Answer 10

nebula

Question 11

the reddening of starlight passing through interstellar dust because dust scatters blue light more effectively than red

Answer 11

reddening