Chapter 21: Lesson 1: The Structure of the Solar System Flashcards
Astronomy
the study of the moon, stars and other objects in space
Solar system
the Sun and the group of objects that move around it
Sun
a star that has a diameter of 1.4 million km and is 10 times as large as the largest planet, Jupiter
Planets
objects that orbit the sun and have nearly a spherical shape. Additionally, a planet must be larger than the total mass of the objects who orbits are close by.
Inner planets
Mercury, Venus, Earth, Mars
Outer planets
Jupiter, Saturn, Uranus, Neptune
Dwarf planets
a spherical object that orbits the Sun
Asteroid
objects that revolve around the sun but are too small to be considered a planet.
Asteroid belt
the region of the solar system where asteroids revolve around the sun- between the orbits of Mars and Jupiter.
Comet
made of ice, dust, and gas and moves around the Sun in an oval shaped orbit
astronomical unit (Au)
the average distance from the Earth to the Sun- about 150 million kilometers
period of revolution
the time it takes an object to travel once around the Sun
period of rotation
the time it takes an object to complete one rotation
Meteoroid
a chunk of rock or dust in space
Meteor
the streak of light you see when a meteoroid enters Earth’s atmosphere and burns up.
