solar system vocab crossword

colliding particles in the early solar system merged together.
the apparent backward movement of a planet.
an oval shape that is centered on two points instead of a single point.
the earth's average distance from the sun.
the shape of a planet's elliptical orbit.
four inner planets, are similar in density to earth and have solid, rocky surfaces.
planet wide system of cliffs.
planets that are all very large, ranging from 15 to more that 300 times the mass of earth
the layer below the liquid hydrogen.
low, warm, dark-colored clouds that sink.
high, cool, light-colored clouds that rise.
an object due to its own gravity, spherical in shape, orbits the sun, is not a satellite, and has not cleared the area of its orbit of smaller debris.
an asteroid fragment, or any other interplanetary material.
a streak of light produced by friction and compression.
the part of a meteoroid that hits the ground.
small solar system bodies that are mostly made of rock and ice that lies out side the orbit of Neptune.
icy bodies that have highly eccentric orbits around the sun.
streaks of light produced by burned up particles left behind from a comet.