Keplers Laws Flashcards
Kepler 1st law
An orbiting body travels in an elliptical path around a central, massive body, which is located at one of the ellipses foci
Two points inside an ellipse
Focal points
When the planet travels around the elliptical
The same time 1 month passes for each interval
Different distances are traveled because the closer to the body the object is the faster it goes
The area of the “triangles” is always the same
An ellipse
Is simply a flattened circle
The long axis of the ellipse contains the two foci is know as what ?
The major axis
Semi major axis
Half the length of the major axis containing the two foci
Eccentricity
Equal to the distance between the foci divided by the length of the major axis
A circle is an ellipse in which the two foci happen to coincide (occur at or during the same time). What is the eccentricity of a circle?
0
The semi major axis of a circle is what
It’s radius
Perihelion
The planets point of closest approach to the sun
Aphelion
A planets farthest distance in orbit from the sun
Kepler 2nd law
An imaginary line connecting the sun to any planet sweeps out equal areas of the ellipse in equal intervals of time
Sideral period
Time taken for a body to complete one full orbit around another
Keplers 3rd law
The square of a planets orbital period is proportional to the cube of its semimajor axis
Astronomical unit
The average distance of earth from the sun
149,603,500 km
