Tagged Questions
6
votes
3answers
171 views
Falling through the rotating Earth
Suppose you were standing on the rotating Earth (not necessarily Equator or the poles) and suddenly your body lost the ability to avoid effortlessly passing through solid rock.
Because the earth's ...
9
votes
2answers
154 views
Can an orbit be calculated using two points and transit time?
Working in only two dimensions and assuming that the central body is at the origin of the coordinate system, given two points in space and knowing the transit time between those points, as well as the ...
12
votes
2answers
1k views
What did general relativity clarify about Mercury?
I frequently hear that Kepler, using his equations of orbital motion, could predict the orbits of all the planets to a high degree of accuracy -- except Mercury. I've heard that mercury's motion ...
2
votes
0answers
137 views
Calculation of a Gravity Resonance Keyhole
Can anyone describe the mathematics behind the calculation of a resonance keyhole (for a two-body model)? It seems like the size and position of the keyhole should be a function only of mass and ...
6
votes
3answers
252 views
How accurately is the moment of perihelion of Earth known, and how is it measured?
Earth's perihelion passed about nine hours ago. How accurately do we know the moment of closest approach of the Earth to the center of the sun? How do we make this measurement?
9
votes
6answers
2k views
Why are the orbits of planets in the Solar System nearly circular?
Except for Mercury, the planets in the Solar System have very small eccentricities.
Is this property special to the Solar System? Wikipedia states:
Most exoplanets with orbital periods of 20 ...
