Planets
A planet has nearly a ___________ shape.
Spherical
The solid inner part of a comet is the _______.
The amount of time it takes the Earth to rotate once on its axis is ____________.
Period of Rotation
Venus is covered by a thick layer of clouds, which are made of ________.
Acid
As a comet approaches the Sun, it heats, changing some ice in the nucleus into _____.
Gas
A planet moves ________ the closer it gets to the Sun.
Faster
Neptune has at least ____ moons and a faint ring system.
13
________ orbits the Sun in an oval-shaped orbit and is made of dust, gas, and ice.
Comet
The amount of time it takes for the Earth to orbit the Sun is __________.
Period of Revolution
Most of Saturn's moons are small, but one of them, _______ is larger than the planet Mercury.
Titan
_________ is a streak of light in the atmosphere made by a glowing meteoroid.
Meteor
This is a spherical object that orbits the Sun, is not the moon of another planet, and has less mass than any of the 8 planets.
Dwarf Planet
The inner planets are closest to the Sun. They are also called the __________ planets.
Terrestrial
Millions of asteroids orbit the Sun between the orbits of Mars and Jupiter in ________ belt.
Asteroid
The outer planets are made of materials that are usually _______ on Earth.
Gases