All Questions
Tagged with astronomy solar-system
136
questions
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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 ...
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1
vote
0
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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 ...
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4
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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 ...
5
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2
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1k
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What is the Metric of the Gravitational Field of the Sun?
What metric determines the "geometry" of the gravitational field generated by the mass of the sun? Is there a general metric that incorporates arbitrary mass and devolves into the ...
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When the new moon will become visible - after how many hours of conjunction
The moon will be totally invisible during Conjunction of moon, sun and earth.
After how many hours of conjunction, moon will be visible from earth.
-5
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2
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391
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Why is mercury the closest planet to the Sun? [closed]
I just want a solid reasoning that why Mercury is the first planet away from the Sun, then Venus, then Earth, then Mars and so on.
12
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6
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6k
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How could Tycho Brahe determine positions without accurate clocks?
Tycho Brahe determined the positions of stars and planets to an accuracy of 2 minutes of angle. Pendulum clocks hadn't been invented yet so he couldn't have known the time to better than 15 minutes. ...
- 165
1
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90
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Earth's rotation axis orientation in space in relation to vernal equinox point
Lately I got confused about how the Earth's rotational axis is oriented during the vernal equinox, as I got information that Earth has an equator ascending node equal to about 11°.
If, this day, we ...
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4
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1
answer
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Drawing night sky of planets other than Earth (invariable plane ambiguity)
I'm writing an application that draws maps of night sky that can be visible from other planets (ultimately they are to be exoplanets). Mostly I do it out of curiosity :).
I's thinking a lot where I ...
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16
votes
8
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3k
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Why is there one fewer solar day per year than there are sidereal days?
solar day = time between solar noons
sidereal day = period of Earth's spin
Wikipedia says "relative to the stars, the Sun appears to move around Earth once per year. Therefore, there is one fewer ...
- 411
1
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1
answer
710
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How to calculate the maximum Elongation of Mercury seeing from the Earth? [closed]
I want to calculate the maximum Elongation of mercury seeing from the Earth but not by this assumption that its orbit is circle but it is an ellipse with semimajor axis a = 0.387 AU and e = 0.2 and ...
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2
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2
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Estimate the eccentricity of the Earth's orbit using equinoxes
I was reading the wikipedia article on Kepler's laws (https://en.wikipedia.org/wiki/Kepler%27s_laws_of_planetary_motion) and I came across the following.
"The eccentricity of the orbit of the ...
10
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3
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2k
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Proof/explanation that Sun is bigger and more distant from Earth than Moon is, Middle Age technology allowed only
If I was living in the Middle Ages, how can someone prove or at least explain to me in a simple way that the Sun is bigger and more far from Earth than the Moon?
Can a parallax be used for it?
$$\text{...
- 191
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0
answers
38
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Is it possible for an undiscovered, large object of the solar system to occult a star on the sky?
Is it possible for an undiscovered, large object of the solar system to occult a star on the sky? Maybe trying to discover it by gravitational effects is hard but can astronomers obseve a occultation ...
- 1,815
2
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1
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86
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Why Earth is viewed crescent from moon when the Earth is experiencing total solar eclipse?
Suppose a person, let's say Neil, is on moon and Earth is experiencing a total solar eclipse so how should Neil perceive the Earth? This is also a question from KVPY (5/11/2017) question no. 22. as ...
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