# All Questions

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### Would it be possible to calculate the expected frequency of impact craters of all sizes on Earth

Can the expected frequency of all sizes of impact craters on Earth be calculated based on the preservation of impact craters seen on the Moon? Taking into account the difference in gravity and ...
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### Spotting the International Space Station (ISS)

Recently, I visited the NASA website which provides sighting locations to see the International Space Station (ISS). As we all know, we can even see ISS with the naked eye in a clear sky as a passing ...
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### Average rate of supernova x number of stars

If we would take the average number of supernovae per year and multiply that by the number of stars, could we figure out how many years it will be before all stars are gone?
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### Sattelite's orbit

What is the maximum distance for a satellite to orbit the earth? Does earth's gravity has the impact on satellite? I do know that earth's gravity will never be zero and it's gravity is inversely ...
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### Determining effect of small variable force on planetary perihelion precession

Is there an analytical technique for determining the effect of a small variable transverse acceleration upon the rate of precession of a planet orbitting around the Sun according to Newtonian gravity ...
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### Adjust axis labels in ds9

How can I adjust the axis labels in ds9? I'd like to have something like: So far I only managed to get floating points (tl h%f3): or the leading hours are missing (tl h%f1 m): Proposed tags ...
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### What was the greatest spatial extent of the Asteroid Belt prior to the Late Heavy Bombardment?

Reading the article On the asteroid belt’s orbital and size distribution (Gladman et al. 2009), there is an interest point made: asteroids a few kilometers and smaller in size are recent ...
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### What are the current observational limits on the existence of Dyson spheres/swarms/rings?

A Dyson sphere/swarm/ring is a hypothetical structure an extra-terrestrial entity would construct to collect a large fraction of its host star's light, and would likely generate a fairly strong ...
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### Mechanisms of binary/multiple star formation

What are mechanisms of binary/multiple star formation in different mass diapasons (low, intermediate and high stellar masses)?
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### Magnetic fields of peculiar HgMn A type stars

Are HgMn (peculiar A type) stars really possess global magnetic fields? See, for example, paper Hubrig et al. 2012: http://arxiv.org/abs/1208.2910
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### Rotation and relativity

When a planet is spinning around its own axis, it has an effect on the trajectory of its satellites. I believe it is called frame dragging. Spin increases the kinetic energy of an object, ...
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### Do solstices and equinoxes shift over time?

Right now, I think the winter solstice is around December 21. Has it always been around this date constantly? Since the earth's axis's 23.45° tilt will be on the exact opposite side in 13000 years ...
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### How to get the longitude/latitude from solar zenith/azimuth?

How do I get the longitude/latitude from zenith/azimuth? Or how can I position my sun in a 3d application? code extracted from here ...