All Questions
Tagged with astronomy orbital-motion
139
questions
3
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1
answer
193
views
Speed at which the Moon moves past a point on Earth's surface?
I'm trying to calculate how fast a point on the surface of the Moon is moving past a point on the surface of the Earth (I assume a point on the equator of each for simplicity).
I know the Earth is ...
- 31
3
votes
2
answers
543
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Is it possible, by monitoring the brightness of stars, to find a “copy of the Earth + Moon” near them?
More than a dozen Earth-like planets have been discovered around nearby stars based on observations of changes in the brightness of their sun as they pass across its disk (transit events). If an Earth-...
- 158
0
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0
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49
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Why does a total solar eclipse happen every 18 Months?
What is the math involved in calculating how often a total solar eclipse happens. Can you predict it by just looking at the period of the moon around the earth and the period of the earth around the ...
- 1
0
votes
0
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55
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Determine the equation of earth's orbit
I am trying to find the the equation earth's orbit using Kepler's Scheme. After every 1.88 years Mars returns to its initial position in the sky.
With reference to the diagram and data below find the ...
0
votes
1
answer
100
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Estimate Saturn's mass [closed]
How can you estimate Saturn's mass using data from Cassini's final moments in September 2017 (apoapsis on September 12 at 1:27 a.m. EDT Saturn time at a distance of about $1.3*10^6$ km from Saturn, ...
0
votes
2
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88
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Why is the time from vernal and autumnal equinox different than from the autumnal to the vernal one?
In my lecture the professor stated that the time from vernal to autumnal equinox is about 186 days , while that from autumnal to vernal equinox is about 179 days.
I was wondering why are these time ...
- 103
1
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0
answers
34
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Orbital obliquity of the Earth
Consider that we have all the orbital parameters that characterize the Earth. How would one calculate the orbital obliquity of Earth?
One could argue that since the rotation of Earth doesn't change ...
- 1,213
4
votes
2
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309
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How do we know when the earth completes an orbit?
Two bodies in space always orbit their center of mass. So the relative motion of the Sun and the Earth happen in the same line, save for the rotation of the Sun. So, how do we measure
The time taken ...
2
votes
1
answer
181
views
Basic: calculating a satellites height from its angular speed
A few days ago, while loooking at the night sky, I saw a satellite and I wondered if it would be possible to tell how far it is just by looking at it. The only possible naked-eye measurement that I ...
- 29
0
votes
0
answers
42
views
Earth's motion in the universe
In the context of working with atomic clocks I have to obtain the orientation of the Earth for every given Julian date. I am trying to obtain a 3d vector summing up all of earth's motions in the ...
1
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0
answers
50
views
Satellite angular velocity at an angle
Suppose I am observing a satellite that is not at my zenith. I know the altitude(α) and azimuth(γ) of my telescope and I was able to get a relative angular velocity of the satellite.
Based on this ...
- 11
0
votes
1
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116
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Orbit of a planet around a black hole
If we observe from Earth a planet in very close orbit around a supermassive black hole (as close as possible to the black hole without the planet being swallowed up or destroyed by tidal forces), ...
0
votes
1
answer
95
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Does the RA and DEC of the sun change with time?
I'm almost certainly misreading this, but it's said that "one of the great advantages of the equatorial system is that the RA and Dec of a star do not change with time, at least over short ...
user332426
-3
votes
1
answer
201
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If barycenter true, then how general relativity explain it?
I found that earth actually doesn't orbit sun. Sun and other planets both orbit the barycenter(Their central of mass).Then, what about Einstein's theory ? That heavy mass(sun) wrap space-time, thus ...
- 7
1
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0
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48
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Satellite’s Position and Path on 2D Map [closed]
When the ISS orbit the Earth, its path traced on a 2D Mercator Earth Map is similar to a sinusoidal wave. I am wondering is there any way to determine the trig function of the wave, knowing the ...
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