Quiz 1 - solar system Flashcards
solar system
the sun and the nonluminous objects that orbit it, including the planets, comets, and asteroids
astronomy
the study of the material universe beyond the earth’s atmosphere
galaxy
a very large collection of gas, dust, and stars orbiting a common center of mass
Milky Way
the hazy band of light that circles the sky, produced by the combined light of billions of stars
local group
nearby galaxies that are moving in concert with each other independent of the Hubble Flow expansion
supercluster
a cluster of galaxy clusters
asteroid
small rocky world; most located in an asteroid belt b/t Mars and Jupiter
comet
one of the small, icy bodies that orbit the sun and produce tails of gas and dust when they near the sun
meteoroid
a meteor that has survived it’s passage through the atmosphere and strikes the ground
ecliptic
the apparent path of the sun around the sky
star
a celestial object composed of gas held together by it’s own gravity and supported by nuclear fusion in its interior
light-year
the distance light travels in 1 year
astronomical unit
average distance from the earth to the sun
plutoid
dwarf planets
Hubble constant
a measure of the rate if expansion if the universe; about 70 km/s/parsec (velocity of recession/distance)
