Tagged Questions
5
votes
1answer
80 views
How is celestial navigation done on a low-level?
When we send a probe off to Jupiter or Saturn, or even Earth orbit, how are the rocket firings timed and coordinated?
For instance, when I want to drive to another city I pull onto the highway and ...
4
votes
4answers
261 views
Are galactic stars spiraling inwards?
Are the stars in our galaxy spiraling inwards towards the center, or are they in a permanent orbit?
And if we are heading towards the center then what is the rate of this process?
I started ...
0
votes
1answer
123 views
Is there a simple, accurate formula for calculating transit times from rise and set times?
I have access to "rise" and "set" times for astronomical objects, and want to determine the corresponding times of culmination. Is there a reliable and accurate way to do this? It isn't clear to me ...
2
votes
1answer
230 views
How did Copernicus establish the relative distance to the superior planets?
I understand that the relative distances to the planets had been calculated using various methods since ancient times, and, in particular, that the assumptions of the Copernican model of the Solar ...
2
votes
1answer
194 views
Did Aristarchus take the radius of the Earth into account in calculating the distance to the Moon?
My text says that Aristarchus (310 BC – ~230 BC) measured the "angle subtended by the Earth-Moon distance at the Sun" ($\theta$ in the figure below) to establish the relative Earth-Moon and Earth-Sun ...
8
votes
3answers
180 views
Are planetary orbits measured from the Sun's surface or centre?
I would imagine planetary orbits are measured from the Sun's centre and not its surface. Is that true?
I can't find anywhere that actually states this.
6
votes
3answers
1k views
What is the irregularity in Uranus' orbit that is caused by Neptune?
I carefully read the Wikipedia article Discovery of Neptune, and I don't get what the irregularity of Uranus orbit was that lead to the discovery of Neptune. Years ago, I watched some educational film ...
