Cosmic Order & Models
Put these in order from smallest to largest: solar system, planet, universe, galaxy.
Planet, Solar System, Galaxy, Universe
What is the third planet from the Sun?
Earth
What is a small rock body that orbits the Sun and can develop a tail of ice and gas near the Sun?
Comet
What force is most responsible for keeping planets in orbit around the Sun?
Gravity
During the earliest stages of the universe, what two elements existed?
Hydrogen and Helium
What is the name of the galaxy that contains our solar system?
Milky Way Galaxy
What is the smallest and innermost planet, orbiting the Sun once every 88 days?
Mercury
What do we call a small piece of space debris, from the size of a grain of sand to a boulder, moving through the space?
Meteoroid
If the Sun's gravity suddenly disappeared, what path would a planet follow?
A straight line at constant speed and velocity
What did Edwin Hubble discover about the universe that is represented by the idea that galaxies are moving apart?
The universe is expanding.
Copernicus proposed the _______ model, which places the Sun at the center of the solar system.
Heliocentric
Which planet is sometimes called Earth's "sister planet" because of similarities in size, gravity, and composition?
Venus
What do we call a flash of light produced when a meteoroid burns in Earth's atmosphere?
Meteor
What two ideas work together to keep a planet in orbit? The Sun's ______ and the planet's ______.
Gravity, Inertia
Where is the Sun located within the Milky Way?
Near an outer arm of the Milky Way
Ptolemy's model was called the _______ model because it placed Earth at the center.
Geocentric
Which planet is the fifth from the Sun and the largest planet in our solar system?
Jupiter
What do we call a meteoroid that survives its trip through the atmosphere and lands on Earth?
Meteorite
According to Newton's law of universal gravitation, any two objects with _____ attract each other.
Mass
Where is Earth located within the Milky Way?
The Orion Spur
Whose rules of planetary motion were based on the heliocentric model?
Johannes Kepler
Which planet is the eighth and farthest from the Sun?
Neptune
What is the region between Mars and Jupiter containing irregular rocky bodies?
Asteroid Belt
Why does the Moon orbit Earth instead of flying away in a straight line?
Earth's gravity pulls the moving Moon into a curved orbit.
Why can Venus not support life as we know it?
The surface temperature is too hot.