What is angular momentum?
The measure of the motion of a rotating object in terms of its speed and how widely the object’s mass is distributed around its axis.
What is aphelion?
The point in its orbit where a planet (or other orbiting object) is farthest from the Sun.
What is apogee?
The point in its orbit where an Earth satellite is farthest from Earth.
What is the asteroid belt?
The region of the solar system between the orbits of Mars and Jupiter in which most asteroids are located; the main belt extends from 2.2 to 3.3 AU from the Sun.
What is an astronomical unit (AU)?
The unit of length defined as the average distance between Earth and the Sun; about 1.5 × 10^8 kilometers.
What is density?
The ratio of the mass of an object to its volume.
What is eccentricity in an ellipse?
The ratio of the distance between the foci to the major axis.
What defines an ellipse?
A closed curve where the sum of the distances from any point on the ellipse to two points inside (the foci) is always the same.
What is escape speed?
The speed a body must achieve to break away from the gravity of another body.
What is a focus in terms of an ellipse?
One of two fixed points inside an ellipse from which the sum of the distances to any point on the ellipse is constant.
What is gravity?
The mutual attraction of material bodies or particles.
What does Kepler’s first law state?
Each planet moves around the Sun in an orbit that is an ellipse, with the Sun at one focus of the ellipse.
What does Kepler’s second law state?
A planet moves faster nearest the sun and slower father from the Sun.
What does Kepler’s third law state?
The square of a planet’s orbital period is directly proportional to the cube of the semimajor axis of its orbit.
What is the major axis of an ellipse?
The maximum diameter of an ellipse.
What is mass?
A measure of the amount of material within an object.
What is momentum?
The measure of the amount of motion of a body; the product of its mass and velocity.
What is Newton’s first law?
Every object will continue to be in a state of rest or move at a constant speed in a straight line unless compelled to change by an outside force.
What is Newton’s second law?
Unbalanced forces cause changes in motion.
What is Newton’s third law?
For every action there is an equal and opposite reaction.
What is an orbit?
The path of an object that is in revolution about another object or point.
What is the orbital period (P)?
The time it takes an object to travel once around the Sun.
What is orbital speed?
The speed at which an object (usually a planet) orbits around the mass of another object.
What is perigee?
The point in its orbit where an Earth satellite is closest to Earth.
