4
votes
1answer
156 views

When will all eight planets in our solar system align?

Ignoring expansion of the universe, entropy, decaying orbits, and interference from any bodies colliding with or otherwise interfering with their orbits, will the eight planets known planets in our ...
1
vote
1answer
79 views

Why planet's orbit is not perpendicular or random ?

Why planet's orbit is not perpendicular or random ? It always seems each planet is revolving on the same geometric-plane around the star.
2
votes
1answer
83 views

What is the orientation of planetary orbits?

I'm working on a planetary motion simulator. I've been working through the equations anomaly, eccentricity, etc. The one thing I'm curious about is if all the ellipses are oriented the exact same way ...
1
vote
1answer
53 views

Rotational speeds of the material forming planets should increase, not decrease

We know that planets form as a result of gaseous material revolving around a center of mass that froze to form planets. However shouldn't the angular speed of that matter increase as they go closer to ...
2
votes
2answers
45 views

How do kepler orbits account for planetary migration?

This article got me thinking if kepler orbits explain how a planet moves in a solar system how can a planet migrate as explained in the article. At some point don't the kepler orbits must need some ...
8
votes
3answers
353 views

Why are orbits elliptical instead of circular?

Why do planets rotate around a star in a specific elliptical orbit with the star at one of it's foci? Why isn't the orbit a circle?
12
votes
2answers
208 views

Is there a upper limit to the number of planets orbiting a star?

Our sun has 8 planets orbiting as well as a number of dwarf planets. Are there any calculations that hint as to whether this number is close to some theoretical maximum value or are we simply an ...
7
votes
1answer
64 views

Do planetary rings have geometric bounds?

Are there any bounds on where a planetary ring can form and maintain orbit relative to the planet? Do they have to be in a circular equatorial orbit? Is there a min or max altitude, say with respect ...
8
votes
1answer
141 views

Changes to Earth's orbit

Any time a spacecraft comes in close proximity to a planet and if the spacecraft has the right angle then it is able to use the planet's velocity to move itself further into space. According to ...
12
votes
1answer
139 views

How do/did we figure out that planets move in orbits?

I've learned that planets move in orbits around the Sun, but I really don't know how I would come to this conclusion myself. I've only seen planets in the sky a couple times (knowingly), and I am ...
2
votes
0answers
64 views

How can I create tracks of the planet's orbits on my computer? [closed]

I'm wondering if there's any good computer software for tracking the orbits of planets over time. I like to see the orbit's trails against the sky background. I'd prefer something that's free and of ...
7
votes
2answers
102 views

Moon orbits crossing each other

Some planets, such as Mars, have 2 or more moons. Giants, like Jupiter of Saturn have a lot of moons! How likely the orbit of one crosses another one's orbit? Is it possible for two moons to collide? ...