The line that runs through both foci of an ellipse (cuts an ellipse in half).

The first person to observe the four moons around Jupiter.

The only dwarf planet located between Mars and Jupiter.

The belief that the Earth orbits the Sun.

List the four Inner planets (IN ORDER!)

Represents the average distance of a planet from the Sun. Half the major axis.

Discovered Pluto in 1930.

This dwarf planet is larger than Pluto and was discovered in 2003.

The belief that the Sun orbits the Earth.

Name the two planets which experience retrograde rotation.

This law states that the orbit of each planet is on an ellipse.

Discovered Uranus in 1781.

Ceres is located in this region of space, between Mars and Jupiter.

A unit of measurement used to measure distances within the solar system. Also, the average distance between Earth and the Sun.

In Keplers equation: P^2 = A^3,
what is the variable P?

This law states that the orbital period squared equals the semi-major axis cubed.

Proposed that the planets orbited on perfect circles, which influenced centuries of astronomers to believe the same.

Pluto is located in this region of space, past Neptune.

The apparent backward motion of a planet.

In Keplers equation P^2 = A^3,
what is the variable A?

This law states that an imaginary line sweeps out equal areas in equal time.

Created a system of circles on circles to explain the apparent backward motion of the planets.

The IAU has 3 criteria for a planet. Which criteria does a dwarf planet not meet?

A small fragment of an orbiting body that has fallen to Earth. It does not completely burn up in Earth's atmosphere, and strikes the surface of Earth.

The orbit of planet A has an eccentricity of 0.07.
The orbit of planet B has an eccentricity of 0.25.
Which planet has a more elliptic orbit?