# All Questions

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### What planet is better than earth to infer solar system configuration?

The mankind had to work some centuries to infer the real configuration of solar system, starting from greeks, Ptolemeus, until Copernicus, Galilei, Kepler, Newton etc. Is there any planet where we ...
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### Time travel possible? [closed]

I once saw on television that if we focus all the light of our sun to a specific point which might create some kind of hole, than we might be able to time travel ( I don't understand how) or if we ...
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### Are we so sure global warming is a result of humans burning fossil fuels? [duplicate]

The Sun is a fiery mass of colliding particles. We still know very little about what it is. Could it possibly be the output of the sun fluctuates, like our weather, from one extreme to another. ...
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### Data analysis projects fora newly renovated desktop? [migrated]

I just renovated a desktop that had been in storage for a while, and I'd like to come up with some big data analysis projects to run on it in the background. Does anyone have any ideas, know of any ...
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### Are there collected data about the direction of rotation of black holes and the direction of the magnetic field?

Is there a relation between the direction of rotation of black holes or neutron stars and the magnetic dipole moment of BH or neutron stars? BTW, are there different directions of this two parameters ...
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### Eclipse in sun-synchronous orbits

I am trying to figure out the eclipse periods of a satellite orbiting the Earth. The satellite is placed on a circular sun-synchronous orbit at 800 km height. The LTAN (local time of ascending node) ...
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### Large hadron collider [on hold]

Whether the collision of particle will lead to a massive WORMHOLE or if BLACKHOLE is also possible? How much I know is that it's created for einstien's E=mc^2 ,conservation of energy from mass and ...
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### Orbital eccentricity variation of the other planets?

On Earth, it's fairly well published, mostly in climate change related articles, that the Earth's orbital eccentricity operates on a 413,000 year cycle with roughly 90,000 - 125,000 year variation ...
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### Is it ever possible that the graviation from the mass of kinetic rotational energy will overcome centrifugal force?

This is, I think, somewhat intuitively obvious, but this comment got me thinking about this: what is gravitational force? "Rotation speed can create centrifugal force opposing gravity and making ...
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### Precision of geocentric gravitational constant

I am looking for an answer as to why the geocentric gravitational constant, μ, defined as the product of the gravitational constant, G, and the mass of a body (earth in this case), M, can be ...
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### Does earth's Umbra reach Sun-Earth L2?

Moon can be fully eclipsed by the virtue of being fairly close to Earth. Any body distant enough will not be eclipsed fully, Earth's disc not fully covering Sun's disc. How's that for anything at the ...
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### Distance of a planet to the star?

QUESTION: Suppose we discover a planet orbiting a nearby star. The distance to the star is 3 pc. We observe the angular radius of the planet’s orbit to be 0.1 arc sec. How many AU from the star is ...
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### How to see other celestial things using stars for direction?

I have a simple question. I can see orion constellation clearly in the night sky. I read it somewhere on this website that gemini is on the left-hand side of orion constellation. I was able to spot ...
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### Tools and algorithms for angles-only orbit estimation

I've seen discussion threads where amateur astronomers estimate a satellite's orbital parameters from angles-only telescope observation. Are there any community tools or algorithms to help with this ...
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### Why is it strange that outer stars are travelling with the same speed as inner while the total mass is also increasing?

Astronomers say that it's strange that the outer stars of a gallaxy are travelling with the same speed as the inner stars. Therefor they introduced dark matter to solve this strangeness. The theory ...
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### Is their any clue where gravitons come from?

Everything which has mass has gravity. Some theories hypothesis that gravitons are responsible for that, but do they have any clue where they come from? Like gluons are interacting between quarks and ...
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### How does an accreting black hole acquire magnetic fields?

There is actually a similar question on this site: Can magnetism escape a black hole?, however the answers do not focus on accretion, which is my main concern, so I start a new one. In Kip Thorne's ...
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### Since the Universe is expanding, is it accurate to say that a galaxy is 5 billion light years away?

Isn't it better to say that the light from the galaxy took 5 billion light years to reach us and it is a very old picture of it? However, if light travelled back to the galaxy at the constant speed ...
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### What happened just before the Big bang?

Does the CMB contain any clues to what caused the Big Bang? Does a mathematical model theorize it?
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### Did the expansion from the Big Bang propagate faster than the speed of light? [closed]

Did the original Big Bang cause an expansion faster than the speed of light? What is the speed of the current expansion with relation to the speed of light? Is it possible for another Big Bang to ...
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### what is gravitational force?

Gravitational force is particle or wave? I know that gravitation depend of the mass and the rotation speed but what is the transmission medium of this wave the same like transmission medium of the ...
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### Is Planet Nine shepherding the Kuiper Belt?

Is it possible Planet Nine is shepherding the Kuiper Belt similar to the way Jupiter shepherds the asteroid belt? I understand that very little is actually known about Planet Nine at this point, but ...
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### How probably is it that galaxies will extinguish?

In the nebulaes of galaxies are stars born, but the gasses and dust they are made of comes from exploded stars (fe supernovas). So it looks like these processes can go on continuesly. But is that ...
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### Is this Universe scenario correct? [closed]

I will try to give you my reasoning behind my scenario. Ok I've researched and found That 95 percent of the galaxy has been formed already, And the other 5 percent is still to ...
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### Is our supercluster part of a galaxy filament?

It was discovered recently that the Milky Way galaxy lies inside a supercluster named Laniakea Supercluster. On the other hand, wikipedia says that galaxy filaments are "the largest known structures ...
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### Why can we observe the Cosmic Microwave Background no matter the direction we look?

I often read that the CMB was released from everywhere in the Universe, in every direction. If that statement is true, can someone elaborate what "everywhere in the universe, in every direction" ...
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### highspeed black holes or neutron stars on (almost) head-on collision course and kinetic energy

First: I don't think this is a duplicate question. There are related question on mergers of black holes that orbit around each other etc., so please read on. I'm having a hard time picturing what ...
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### Can a drastic change in a stars cycle cause harm or affect a nearby star system?

If Alpha Centauri A our neighboring star happens to shift into a Red Giant or a Planetary Nebula, Will our star system be affected? And if so is there a ripple effect throughout the galaxy causing a ...
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### Have any planets been discovered in Orion constellation?

Orion constellation is a very famous constellation. It can be seen throughout the earth. Orion looks like a warrior with a weapon and skirt. I see this constellation daily and wonder, if there is a ...
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### Does every object in the Universe have gravity? Space has no gravity, why?

My science teacher told me that every object in Universe has gravity but space is a part of Universe too, so, why does the space have no gravity?
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### What was “space” like before big bang?

I have a simple question which I think about often but have no answer. If The Big Bang is true, than if the whole space was just a point 14 billion years ago, then what was around that point, some ...
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### How do we know the current state of the universe by observing it from Earth?

Since light travels at the constant speed and takes more than a billion years to travel from the distant parts of the Universe, how do we know the state of the distant regions? Do those still exist or ...
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### Can “dark matter” be the additional mass from the speed of the Galactic Cluster?

Considering that the Earth orbits the Sun at 100 000 km/h and that the Sun orbits the Milky Way at almost 1 000 000 km/h, could it be possible that the galactic cluster orbits some super cluster at ...
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### plane of moons orbit, self spin with respect to earth's self spin and orbit around the sun? [closed]

is there an image of plane of moons orbit, self spin with respect to earth's self spin and orbit around the sun? is that Geodesy related or Astronomy related?
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### What is spacetime 'made' of?

General relativity is often explained as saying spacetime is curved by gravity, what does this mean? How could we perceive a curve in spacetime when there is no external "straight" reference frame for ...
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### Is there sufficient evidence to confirm additional Planet in solar system

I have watched this scishow episode where Hank says that astronomers believe there is another planet in our solar system. Link He says that it's because how asteroids and comments are being pushed ...
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### Is there really no difference between up and down in ISS? [migrated]

ISS is actionally falling towards the earth and therefor they don't feel gravity. But ISS is falling in a direction towards the earth. So the astronauts living in ISS probably live in ISS in a manner ...
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### How can a naked singularity be possible?

How can we have a singularity, without a black hole around it? How would one form? What does it do?
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### Astronomy Jokes [migrated]

Disclaimer: I battled with myself for a few days over whether it would be a good idea to post this question on Astronomy SE. Inspired by Jon Skeet Facts question on Meta SO, I decided to go for it. ...
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### Red dwarf variation in Luminosity

I recently saw this video. The creator of the video says that one of the reasons for non-existence of life on planets around red dwarfs might be that these stars can increase luminosity roughly by a ...
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### Why do planets tend to rotate in the same direction although they have formed from tumbling asteroids?

The axial tilts of asteroids seem to vary randomly (let me know if this premise is wrong), while the planets have a strong tendency to rotate in the same way. If planets were formed by colliding ...
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### Angular Separation

Two stars A and B are located on the celestial equator. The RA of star A is 02h 0m 00s and that of star B is RA 07h 00m 00s. What is the angualar seperation between star A and B?
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### Compared with similar stars, does the sun itself have properties that make life on Earth possible?

We often hear our solar system has properties for life. For example, it is far away from the center of Galaxy. It has Jupiter far away to protect us from asteroids. It has optimum size of territorial ...
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### Why are stars more metallic closer as you move closer to the galactic bulge?

As I see it, most of the stars in the galactic bulge are Population I stars. However, as one moves farther from the galactic bulge, star metallicity decreases. In fact, halo stars are almost entirely ...
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### Why argon instead of another noble gas?

I noticed that the atmospheres of Earth and Mars have a little bit of argon in them (1% to 2%). I checked Venus, too, which has 0.007% argon, but that's still more than any other noble gas in the ...
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### Where can I find/visualize planets/stars/moons/etc positions?

What resources are available to find the positions of planets, stars, moons, artifical satellites, asteroids, and other heavenly bodies?
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### Is the Earth going to evolve towards Mars' fate or Venus' fate?

Upon reading on this site (and many others), one can think that Mars might have supported life in a distant past (discovery of liquid water, valleys, mountains...). On the other hand, Venus is the ...
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### What accounts into calculating the Hubble constant?

From my understanding, the Hubble constant $H_0$ calculates from observed redshifts $z$ of distant galaxys against their proper distance $D$. The current value appears to be 67.80(77) ...