# All Questions

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### Why Earthian atmosphere is so thin?

Venus is somewhat lighter then Earth, yet has a much thicker atmosphere. One would imagine that the following should be true: During the formation phase, all inner planets had captured as much gas ...
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### Can a astronomical telescope view objects on Earth

I am new to telescopes, and planning to buy an astronomical telescopes like "Celestron AstroMaster 114 EQ Reflector". Just curious to know that whether it can be used to view objects on earth ...
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### What is space temperature around Earth?

What is the equilibrium temperature that a black body will reach at the Earth's distance from Sun?
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### How long is the moon full

Is the moon the most full only for one moment As stated here and here Or does if stay the same full for a longer period of time (maybe because, the sun is grater then it, and light spreads out) ...
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### How do I remove fungus from a telescope mirror?

I use a Celestron NexStar 130SLT Azimuthal Newtonian Reflector. I noticed that recently, due to the wet season, some tiny spots of what appears to be fungus have appeared. Having taking appropriate ...
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### What makes the moon, a super moon

Caught a sight of moon tonight (by chance) and came in surprise that moon looks thrice in size to its usual size. Mostly called as Blue moon. Didn't succeed in getting the details and explanations ...
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### Has the conjunction between Venus, Jupiter, and Regulus only occurred twice in 2,000 years?

I recently heard the claim that mid-July, the "Star of Bethlehem" formed for the first time in 2,000 years, where the Star of Bethlehem is a three-way conjunction between Venus, Jupiter, and Regulus. ...
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### Could spy satellites use laser guide stars (for adaptive optics)?

Are sodium lasers useful for Earth observing space telescopes/spy satellites?
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### Review Content for my Comet Infographic

I've been hard at work in recent months on an infographic that details the anatomy of a comet... I'm a graphic designer and this is a fun little side-project of mine. It's only quite basic in terms of ...
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### What is the difference between Space Dynamics & Astrodynamics in the engineering perspective? [migrated]

Within the context of Aeronautics, there are seemingly different meanings corresponding to Space Dynamics and Astrodynamics... ...
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### Which structure is represented in this video (if any)?

I know this is not supposed to be precise since it is just a movie but I would suppose it is based on real things. In the Contact movie intro https://youtu.be/EWwhQB3TKXA?t=1m I think the Milk Way is ...
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### Does the shape of a supernova remnant depend on the progenitor star's magnetic field?

The magnetic field activity in a star can be very chaotic and my question is are they somehow related?
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### Do magnetic fields affect planetary rings?

Planetary rings seem to generally form on the ecliptic plane because of the rotation of the planet, but I was wondering what kind of effect the magnetic field of the planet might have on the ring ...
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### How easy is it to mine water on Ceres?

It has been suggested by some futuristic or sci fi leaning thinkers, that Ceres' surface might be mined for water to support human exploration and settlement of space. But NASA's Dawn mission and ...
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### How thick can planetary rings be?

This arose from a comment on Worldbuilding. We have data from four planets in the Solar System with rings, which doesn't make for a very good sample size. Observations of exoplanets could change ...
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### Available energy for potential life on Titan

There is an interesting discussion about whether there could be life on Saturn's moon Titan. (For example here.) The life could use reaction of hydrogen and acetylene which are being produced by ...
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### Orbiting and landing on non-sperical objects

If we orbit a non-spherical asteroid or moon at a sufficient distance I believe that we can consider it to be a point mass. Therefore we can take up a conventional orbit. Assuming our lander craft is ...
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### How can exoplanet moons be detected? [duplicate]

How can exoplanet moons be detected? Are there current methods to differentiate exoplanets with moons and exoplanets without moons? Or, are only the combined masses of the exoplanet and its moons ...
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### Why do some artificial satellites decrease and increase in brightness multiple times?

I just observed a satellite almost directly above me travel for a few minutes while constantly dimming and then getting brighter. It did this for about 3 minutes until it faded out. I also observed a ...
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### About the reference for equation of state

Well, I am a post graduate studying mathematics. Current I am working on the mathematical theory of star(not an expert thought). When I am making some assumption on the equation of state (for a star ...
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### What would Earthlike planets bigger than Earth with <10 m/s^2 gravity and complex life be like? [closed]

Large is bigger than Earth. Assuming that such planets exist (though I guess if such planets don't exist that would explain much of the Fermi paradox). Maybe some amount of iron is needed though, to ...
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### If your near a black hole and your time is slowed down, would a supernova be observable to both you and someone outside of the blackhole's pull?

Let's say that Person A is on a planet orbiting a blackhole(Like the one from interstellar) and time is slowed for Person A. Person B is back home on Earth. Now let's say a supernova happens and it's ...
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### Galaxy Cluster Temperature

I've read once in an article that the temperature of the medium between the galaxy superclusters is extremely high. What does that temperature really mean? particles' velocity? Why is that so? Is ...
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### Are there any Stars we know don't have planets?

We have been looking for planets around other stars for a while (see related Are there any other Earth-like planets in the universe? ) and we are finding lots of planets, some of them are Earth like ...
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### why does pluto have a high orbital inclination

Pluto has a high orbital inclination compared to the planets in our solar system. What has caused Pluto to have such a different orbit -- was it always like this, or did something happen to make it ...
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### Linear motion in the equatorial frame

I would like to calculate how the RA/Dec changes when an object has an apparent linear motionin the equatorial sphere. For example, more or less what an artificial satellite would do in a circular ...
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### During night on the Moon is there Earth light and Earth phases?

I realise that night time on the Moon is two weeks, however I am curious if during the night there, whether or not the Earth reflects light in similar manner to the Moon. On the one hand, I know it ...
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### First time visit to dark sky stargazing site: what do I need?

Complete newbie here. I have an opportunity to visit one of the few designated dark sky sites here in Pennsylvania, Cherry Springs State Park. I plan on camping out over night, but I have never gone ...
I want to calculate the distance between two quasars of which I know the angular position and the red shift. Let $Q_1=(\alpha_1,\delta_1, z_1)$ and $Q_2=(\alpha 2,\delta 2, z_2)$ and suppose \$z_2 > ...