Elliptical orbit parameterized by time

In summary, expressing an elliptical orbit in terms of time is not as straightforward as it is for a circular orbit. The analysis from Newton's laws does not provide an analytic formula for position as a function of time, and only describes the orbit in terms of the shape (ellipse) and period. Further research on "The Kepler Equation" may provide more insight into this topic.
  • #1
DuckAmuck
236
40
TL;DR Summary
How to express an eliptical orbit in terms of time
It is fairly trivial to do this with a circular orbit: $$(x,y) = (cos(\omega t),sin(\omega t))$$
where t is time, and $$\omega = \sqrt{GM/r^3}$$
How this parametric equation look for an elliptical orbit?
 
Physics news on Phys.org
  • #2
DuckAmuck said:
Summary:: How to express an eliptical orbit in terms of time

It is fairly trivial to do this with a circular orbit: $$(x,y) = (cos(\omega t),sin(\omega t))$$
where t is time, and $$\omega = \sqrt{GM/r^3}$$
How this parametric equation look for an elliptical orbit?

I don't think it works out very well. Have you tried?
 
  • #3
Yes. I get something non-analytic.
 
  • #4
DuckAmuck said:
Yes. I get something non-analytic.
I think that's what you get. The analysis from Newton's laws bails out at a certain point and describes the shape of an orbit in terms of ##r## and ##\theta##, but eliminates ##t##. You get the shape (ellipse) and the period, but not an analytic formula for position as a function of time.
 
  • #5
Look up "The Kepler Equation". You're in for an interesting ride!
 
  • Like
Likes phyzguy, vanhees71 and DuckAmuck
  • #6
gneill said:
Look up "The Kepler Equation". You're in for an interesting ride!
Thank you!
 

1. What is an elliptical orbit?

An elliptical orbit is a type of orbit in which an object, such as a planet or satellite, follows a path that is shaped like an ellipse. This means that the distance between the object and the body it is orbiting around is not constant, but instead varies at different points along the orbit.

2. How is an elliptical orbit parameterized by time?

An elliptical orbit can be parameterized by time using Kepler's laws of planetary motion. This involves using mathematical equations to describe the shape, size, and orientation of the ellipse, as well as the speed at which the object travels along its orbit at different points in time.

3. What are the key parameters used to describe an elliptical orbit?

The key parameters used to describe an elliptical orbit include the semi-major axis, eccentricity, inclination, longitude of the ascending node, argument of periapsis, and time of periapsis passage. These parameters help determine the size, shape, and orientation of the ellipse, as well as the position of the object along its orbit at a given time.

4. How does the eccentricity of an elliptical orbit affect the object's motion?

The eccentricity of an elliptical orbit determines how elongated or circular the orbit is. A higher eccentricity means a more elongated orbit, while a lower eccentricity means a more circular orbit. This affects the object's motion by causing it to move faster when it is closer to the body it is orbiting, and slower when it is farther away.

5. Can an object in an elliptical orbit have a constant speed?

No, an object in an elliptical orbit cannot have a constant speed. This is because the object is constantly changing its distance from the body it is orbiting, which affects its speed due to the laws of gravity. However, the object's speed will be constant at a given point along its orbit if it is in a circular orbit.

Similar threads

Replies
1
Views
544
Replies
4
Views
722
  • Mechanics
Replies
6
Views
1K
Replies
8
Views
1K
  • Classical Physics
Replies
9
Views
984
Replies
12
Views
1K
Replies
1
Views
2K
  • Astronomy and Astrophysics
Replies
5
Views
1K
  • Introductory Physics Homework Help
Replies
3
Views
1K
  • Introductory Physics Homework Help
Replies
10
Views
250
Back
Top