Astronomy Practice

formation of the Milky Way Galaxy

Big Bang

origin of the Sun

radioactive decay in Earth’s core

180°

90°

360°

30°

Earth revolves around the Sun

Orion rotates on its axis

Orion revolves around the Sun

Earth rotates on its axis

gravity and percent of water in the planet’s composition

distance from the Moon and percent of water in the planet’s composition

distance from the Moon and densities of materials making up the planet

gravity and densities of materials making up the planet

circular with Earth at one focus

circular with the Sun at one focus

elliptical with Earth at one focus

elliptical with the Sun at one focus

Saturn, period of revolution = 29.5 years

Venus, period of revolution = 224.7 days

Jupiter, period of revolution = 11.9 years

Mars, period of revolution = 687 days

low density and large diameter

high density and large diameter

low density and small diameter

high density and small diameter

red shifted due to a contracting universe

red shifted due to an expanding universe

blue shifted due to an expanding universe

blue shifted due to a contracting universe

a collection of stars orbiting the Sun

one of billions of galaxies in the universe

a star that originated 4,600 million years ago

an elliptical galaxy

the evaporation of water from a lake

the subduction at a plate boundary

an explosive volcanic eruption

an asteroid colliding with Earth