Questions tagged [space]

The near-vacuum extending between the planets and stars, containing small amounts of gas and dust. Also called outer space to refer to the physical universe beyond the Earth's atmosphere.

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If the universe is a closed spacetime structure, can we assign a center of mass to it?

If we envision the universe like a balloon but in 3D, is it possible, in general, to assign a of global center of mass?
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5 votes
1 answer
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Why not build a swarm of space telescopes?

James Webb Space Telescope (JSWT) has not yet started doing science, yet it's successor LUVOIR is being discussed already. However I am curious; some countries have invested billions of dollars in ...
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Will Jupiter's days speed up?

Jupiter has so many moons, and those moons have a gravitational pull on it. Does that mean, that over time, the length of Jupiter's days will get shorter?
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3 answers
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How to choose eyepieces and other accessories for a Celestron 70mm f/5.7 portable refractor?

I have a Celestron Specialty Series Travel Scope 70mm refractor which came with 10mm (40x) and 20mm (20x) eyepieces. Specifications: Focal ratio: f/5.71 Optical Design: Refractor Aperture (mm): 70 mm ...
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2 answers
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Horizontal and equatorial coordinate systems

What is the difference between horizontal and equatorial coordinate systems apart from the notations (azimuth, altitude) and (right ascension and declination angle)? Please provide some measurements ...
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How will be changed Hill's radius and Kepler's formulas in case of 2D space instead of 3D?

Imagine that Flatland habitats go into space. All stars and planets are the circles instead of spheres and gravity law is $F=Gm_1m_2/R$ instead of $F=Gm_1m_2/R^2$. How the other formulas will be ...
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What is the concept of wormholes? [duplicate]

My main queries for now I guess: What is the theory behind wormholes? What is the possibility and likeliness of their existence based on scientific analysis, not conspiracy theories? What is the ...
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3 votes
1 answer
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Not getting quality images in telescope

I have a Newtonian telescope (Celestron 130 eq) with 5.2 inch (~132 mm) aperture with 650 mm focal length, Spherical mirror. And having 4mm, 10mm, 12.5mm, 20mm,20mm (erecting eyepiece), a 3x and 1.5x ...
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Because the Universe is expanding, what is it taking up?

It is my understanding that the universe is expanding and that matter takes up space. While the universe only contains small percent of matter, wouldn't expansion indicate that the universe is ...
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Weight of a gas measured in Space and other planets of Solar System

I searched for how measure gas weight and about gases in space https://www.shutterstock.com/search/space+gases https://education.seattlepi.com/gases-found-outer-space-5888.html Will the weight of gas ...
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Can two neighboring galaxies move apart at steady speed?

While I was trying to understand the three models that obey Friedmann's two assumptions of a non-static universe, I came across a line that says and I quote "It (referring to Big Bang) starts at ...
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30 votes
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Could liquid water have existed in open space 15 million years after the Big Bang?

Around 15 million years after the Big Bang, the ambient temperatures was about $24^\circ {\rm C}$, which is in a range where water could be liquid. Could liquid blobs of water be existent then? PS: I ...
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How do we know that spacetime is fabric? [closed]

I have started learning about astronomy as it amazes and inspires me. I have a question. What led us to believe that spacetime is fabric? What is the evidence shows this, and is it considered proven? ...
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Density of stars on celestial sphere

The pattern of stars on the surface of the celestial sphere seems perceptually to have an universally looking structure. If you pick a region of the sky at random, for instance by using the (excellent)...
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Why do people say travelling at the speed of light or faster is impossible? [closed]

Impossible assumes we know everything there is to know about, well, everything. There was a time when everything mad knew said that traveling faster than the speed of sound was impossible. These same ...
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5 votes
1 answer
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Source of the odor in space

If space is a vacuum, then how can it contain an odor? I read that after spacewalks, astronauts detected an unusual odor after removing their spacesuits. It was compared to the smell of a candle ...
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Why is Space 3D?

Why is Space a THREE DIMENSIONAL ENTITY? I know that In physics and mathematics, the dimension of a mathematical space is informally defined as the minimum number of coordinates needed to specify any ...
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Is sky-glow affected by height?

I'm an architecture student and my graduation project will consist of building a research center for outer space, my question is whether or not height would affect sky-glow or not ? Thanks in advance, ...
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3 votes
1 answer
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Type II supernovae as a distance indicator

Could someone explain in brief exactly how type II supernovae could be used as distance indicators? as in simply the formulae used and how they are employed? I know there are certain methods based on ...
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Why is the solar wind most powerful near the heliosphere?

I've read this article, titled, "Voyager Mission Finds a New Type of Electron Burst at The Edge of Our Solar System". They state that, Carried to the fringes of our Solar System by the ...
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Where can I find galaxy spectra (in the form of FITS files)?

I know there's SDSS and I tried searching for the spectra through the navigate and explore tool under CAS as well as by using RA/Dec coordinates under SAS, but every single time it comes out with 0 ...
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what would the mass and density of Sirius A be if the mass of Sirius B is roughly the same as the Earth?

I am writing a blog post and while I am interested in astronomy I havent done any physics like this since high school. My question is: what would the mass and density of Sirius A be if the mass of ...
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2 votes
1 answer
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Relation between mass of gas, mass of stars and dark matter halo mass [duplicate]

As we all know that Mass of the galaxy can be written as the sum of the mass of gas(Mg), the mass of stars (Ms), and mass of dark matter halo(Mh), as M(galaxy)=Mg+Mh+Ms, But is there any formula which ...
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1 vote
2 answers
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List of galaxies with their dark matter halo

Where can one find the list of galaxies with their dark halo masses, I've searched several sites but I found no such proper list where the masses of their dark matter halo is compiled? Can anybody ...
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6 votes
2 answers
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How accurately could late 50s - early 60s humans have mapped the solar system?

What if early SETI investigations had focused on our own solar system, rather than distant stars? Given the technology that existed around the 1950s, how much surveillance would humanity be able to do?...
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-3 votes
1 answer
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Has the idea of sending human heads instead of entire human bodies been considered in space exploration? [closed]

What makes human space exploration very difficult is the infrastructure require to support a human body outside earth. It must be researched, developed and tested thoroughly which can take many years ...
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Picking two random points in space and drawing a line between them, what is the chance the line intersects anything?

I thought of this question after pondering how most of the observable universe is observable. If we can observe it, then the space between us and that object must have been unoccupied to allow the ...
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-1 votes
1 answer
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Why is the position of the Sun so fixed? [duplicate]

Please correct me if I tell something wrong. As we already know, a planet (e.g. Earth) remains on its orbit due to the gravity of the Sun. If the Sun's gravity were not there, the Earth would be ...
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1 vote
1 answer
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Is it possible to use the vacuum of space to help with pollution [closed]

Would it be possible to use a pipeline from the ground and uses the vacuum of space to dispose of things that are hazardous to the environment? (Liquid waste in particular comes to mind) Essentially ...
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1 vote
1 answer
347 views

What would happen if you jumped out of a moving spacecraft? [closed]

I've watched a film where one of the characters claimed to have rapidly disembarked a moving spacecraft during a 5g burn (?!) and immediately wondered how he survived. For example, you're on a ...
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2 votes
0 answers
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Definition of space - to cope with "space expansion"

I've searched quite a lot but found no satisfying definition, so please: How do we actually define space when talking of "space expansion"? Isn't it just a metric, a dimension we measure, instead of ...
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38 votes
2 answers
6k views

How can comets have tails if there's no air resistance in space?

I understand that solar radiation causes material to vaporize out of a comet into dust but why does the dust then trail behind the comet like a "tail"? Assuming gravity is the only applied force ...
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2 votes
1 answer
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Was it a space station?

I just looked at the sky and saw a star, not so bright but moving very fast and in almost a minute it disappeared, as it was so fast. Timing was in between 9.35-9.45 PM in Nuremberg, Germany. My ...
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2 votes
0 answers
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Galaxies stay at same place but it's the space that splits the galaxies apart [duplicate]

Galaxies stay at same place but it's the space that splits the galaxies apart. Is my understanding correct? As per my understanding. Galaxies moving apart at high speed is due to the increase in ...
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If a black hole pulls every object in the universe, why there is a light around it?

I've seen some black hole images and I've seen some movies about it e.g(interstellar). I wonder why it has a light around it. Even if I know that light can't escape through it. Can someone enlighten ...
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Underground sea in Titan(Saturn's moon), water or hydrocarbons?

Is the underground sea on Titan formed of water or hydrocarbons. Is anyone certain? I have read a lot of various documents from NASA and Cassini missions and Huygens missions, and I have become ...
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2 votes
1 answer
148 views

How long could an ocean last in space?

If all of Earth's oceans were suddenly moved into outer space, how long would it take for them to evaporate? My understanding is that water evaporates straight away in space... but what about when it'...
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14 votes
2 answers
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Space telescope located in outer solar system

I want to pose a question from someone who's astronomy knowledge would fit neatly onto a single piece of paper so please bear this in mind with any comments or answers. I am interested and want to ...
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What is the horizontal distance needed to observe an object just as badly as if it where in space at the zenith?

When I see an object in space (let's say the ISS) above my head, my line of sight traverses ~$100\; km$ of atmosphere. The vast majority of the extinction, absorption and turbulence happens closer to ...
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1 answer
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Force exerted by space debris on satellites [closed]

Hypothetically, if space debris were to collide with the currently orbiting satellites, how much force would they exert, and how much damage would they make? Will the satellites be able to withstand ...
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1 vote
2 answers
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The origins of Dark Matter/Dark Energy

Layman here with an affinity for astronomy, space and everything associated with it. I'm a big fan of the space oriented programs on the Discovery and Science channels and I was watching an episode ...
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6 votes
1 answer
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Starting a fire in a cold planet that was full of flammable gas

What would happen to a cold planet that has a large amount of flammable gas, like Neptune, if we throw some fire into it? Will it burn, or would the flame be extinguished due to the cold?
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2 answers
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Why was Dawn's (the spacecraft) flight path circular? [closed]

In comparison to the twin Voyagers, Dawn's flight path circled the sun in an anti-clockwise manner. The map of its path shows its targets, Ceres and Vesta were in a trajectory that was close to a ...
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-5 votes
1 answer
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What is this object in this photo? [closed]

i took it and i don't know what planet or star is this and also there's our moon
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-1 votes
1 answer
115 views

Latest Planet Collision 2019 [closed]

Scientist says that during the course of their billions of years, the planets collied with each other in the past. My question is: is there any latest or recent planetary collision in recent times?
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8 votes
3 answers
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Attach a visible light telescope to the outside of the ISS

Visible light imaging of the heavens is limited on Earth primarily due to the atmosphere. I know the ISS is moving at 17000mph, but given the delays to the James Webb telescope, is there any merit in ...
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Is the newly discovered exoplanet 'Teegarden b' habitable?

A new exoplanet has been just discovered around the star Teegarden, at only 12 light years away.
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1 vote
1 answer
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If the space is expanding near the speed of light or the speed of light, why Andromeda is approaching or coming near to our galaxy (Milky way)? [duplicate]

Space with distance of 1megaparsec is expanding with rate of 70km/s, and if space with a distance of 4296 megaparsec is expanding at rate of 300,720km/s, then why Andromeda is coming to us? Even there ...
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Water vapour in space

This question is inspired by, but different from, What happens if an ice cube is left in space? Mark's accepted answer says "…if you stick your ice cube out in the Oort Cloud, it'll grow: the mean ...
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0 votes
1 answer
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Birth of the Gas Giant Planets?

How does a gas giant planet form like Saturn and Jupiter, and why just gas? Why didn't they form any solid surface?
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