galaxies
a large collection of stars, dust, and gas held together by gravity
what is a galaxy?
the location of our solar system (in relation to the Milky Way)
2 characteristics of inner planets (size and composition)
what is smaller and made mostly of rock?
2 characteristics of outer planets (size and composition)
what is larger and made mostly of gas?
the only star in our solar system
what is the sun?
a galaxy shaped like a pinwheel with many arms
what is a spiral galaxy?
the distance light can travel in one year
what is a light-year?
the smallest rocky planet
what is Mercury?
largest planet in our solar system
what is Jupiter?
a large, round object in space that orbits a star
what is a planet?
a rounded galaxy shaped like a stretched-out circle
what is an elliptical galaxy?
the region between the inner and outer planets
what is the asteroid belt?
the hottest planet in our solar system
the order of the outer planets
what is Jupiter, Saturn, Uranus, and Neptune?
a mixture of frozen gases, ice, dust, and rock that move in an elliptical orbit around the sun
what is a comet?
a galaxy with no distinct shape
what is an irregular galaxy?
astronomers believe the center of the Milky Way contains...
what is a black hole?
the order of the inner planets
what is Mercury, Venus, Earth, and Mars?
the outer planet with an extreme tilt; rotates on its side
what is Uranus?
a rock that revolves around the sun (often shaped like a potato)
what is an asteroid?
the closest major galaxy to the Milky Way
what is the Andromeda Galaxy?
the speed of light is...
what is 186,000 miles per second?
the inner planet with 2 moons
what is Mars?
the largest moon orbiting Saturn
what is Titan?
the year humans walked on the moon for the first time