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For questions related to outer space, stellar systems, stars and other astronomical phenomena.

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2answers
92 views

A balloon that can float to space [on hold]

I’ve heard there are materials that can withstand the image sort of the earth’s atmosphere, such as carbon nanotubes and Kevlar. Supposedly, a perfectly constructed bridge of such material could be ...
0
votes
2answers
250 views

If a human had metal bones that were completely inflexible, would this cause any ill effects?

I've got a subspecies of human, Homo Volantes, that has been designed to live both in zero-G and in surface gravity. Several adaptations have been made, one of them including the replacement of ...
12
votes
3answers
296 views

How far from the Sun could we detect an alien spacecraft similar to the Voyagers?

Suppose that there is an alien spacecraft travelling towards the Sun. This spacecraft is similar in design, size and power output to Voyager 1 and Voyager 2 as they were immediately after launch from ...
23
votes
10answers
5k views

How to improve TCP/IP for an interplanetary WAN?

Background It is the near future. After a major world war and limited nuclear exchange, the nations of Earth have consolidated into a few blocs. The threat of further war and the cumulative damage to ...
1
vote
2answers
98 views

Threats within 100 light years

So I'm making this game where the player has to launch probes into interstellar space within a 100 * 100 light years map to detect threats that could wipe out humanity in a few decades. Everything is ...
7
votes
2answers
236 views

Are there currents in space? Space flotsam?

You know how there are some beaches in the world where tons of sea glass or other random sea trash washes up, just because the currents and the shape of the land naturally collects it all there? I was ...
1
vote
1answer
104 views

Big moon, small planet - can an earth sized moon orbit a moon sized planet?

I know that objects with lower mass tends to orbit objects with higher mass, is it possible to have a Moon sized planet who's mass is so heavy that an Earth sized planet orbit it as it's Moon in a ...
3
votes
4answers
242 views

Is it possible for a naturally occuring star system to have 120 planets?

In my book series (link here), there is a star system at the northern edge of the galaxy called the Ryu system. I am planning for this star system to be huge, encompassing 120 planets. The vast ...
29
votes
14answers
6k views

Is it possible to rule a galaxy without mastering teleportation?

I would like to know if a very advanced civilisation could rule an entire galaxy without mastering teleportation or any other method that allows traveling faster than light (unless you give ...
12
votes
1answer
206 views

How much electromagnetic transmission noise does Earth have to emit to be noticeable?

From time to time I'll see things talking about how thanks to all of our radio communications, we're effectively broadcasting our existence to the entire universe. However, when I did some back-of-the-...
1
vote
1answer
125 views

How do I create the largest possible space habitat for humans? [closed]

So I'm making a post-FTL world in which humans are the first, and so far only, species to explore the stars. It's thousands (if not millions) of years in the future, and we've become post scarcity. ...
3
votes
1answer
74 views

Terraformed planet orbiting a blue star

A planet was terraformed in humanity's distant past by technologically superior beings. The planet is very similar to Earth. I understand blue stars are highly radioactive and thus don't have real ...
8
votes
3answers
425 views

Could mirrors be put in space to see ourselves in the past?

Could a mirror/s be made to reflect one side of the Earth from the edge of the solar system and viewed with a optical or radio telescope that is in orbit? With night vision, along with radio and ...
13
votes
5answers
2k views

Why did US government hide the discovery of an ancient civilisation on the moon? [closed]

July 20, 1969, Neil Armstrong sets his foot on the moon surface. He declares : "That's one small step for [a] man, one giant leap for mankind". But what history books don't mention is that, as he ...
17
votes
5answers
3k views

Could deliberately induced Kessler Syndrome stop ICBMs?

In a previous question I asked how Mutually Assured Destruction could be made not assured. Most of the highly rated answers focused on political methods, but one answer raised the possibility that ...
3
votes
3answers
167 views

Largest artificial planet

How large could a solid planet be (in theory) without becoming a star or black hole? Too much in the way of light elements would lead to thermonuclear ignition, but too many heavy elements would ...
9
votes
4answers
2k views

Can I have wind turbines on my base?

Background A colony of humans has settled on a remote planet where there is little to no sunlight, but there is a plentiful amount of earth metals. E.g.- Iron, aluminium, Titanium, etc. There are ...
0
votes
3answers
61 views

How to interface with beings in the galactic core?

Context: So assume there are an unknown number of near-omnipotent/omniscient beings who have been confirmed to live inside of an area of space called the Active Galactic Nucleus (AGN). To provide a ...
-1
votes
0answers
33 views

What is the minimum amount of population to restart population with enough genetic variation? [duplicate]

Lets assume different cases: Case A It is a space colonial project , and it is able to choose member with maximum genetic diversity and perfect genes that has no disease. Gender ratio and age can be ...
-1
votes
3answers
106 views

Extraterrestrial blackmail by reversible sun block [duplicate]

In a near future scenario where humanity has a slightly more developed/active space flight. Think colonising the moon with regular space flights back and forth. But no fancy interstellar tech. ...
18
votes
6answers
388 views

Can my spaceship figure out its position using Cepheid Variables?

In my story, reasonably far in the future, an intrepid group of explorers are on the first manned mission to the Andromeda galaxy, travelling close to the speed of light. They slumbered in suspended ...
0
votes
2answers
144 views

Peeping at Antipodes: How long would it take to peek around the sun using modern technology?

Assuming humanity was suddenly highly motivated to do it, how long would it take a probe launched from Earth to get into a position to record and broadcast images of the position in the opposite orbit ...
12
votes
3answers
1k views

How fast would a Martian space elevator travel?

READ EDITS I am writing a passage about the main character of my book travelling up a space elevator to the spaceport that rests in geostationary orbit above Mars. This means that the elevator would ...
10
votes
7answers
648 views

Which part of the universe would make celestial navigation most difficult for a planet?

Premise I envisage a world of would-be navigators with roughly Bronze Age technology, sailing on ships to explore their planet. In contrast to our history of navigation where we "cracked the code" ...
0
votes
3answers
172 views

What makes humans so special amongst the thousands of civilizations? [closed]

Alas, the galaxy has been colonized for many millenia. Hundreds, if not thousands, of advanced civilizations have emerged. Empires have risen, fallen, and the scourge of intelligent life forms ...
1
vote
3answers
187 views

Minimum required technology for a species to reach space?

Ok so first of all, let's imagine a civilisation on a planet. The planet has a relatively low escape velocity, say 6 km/s and maybe an atmosphere 30% - 50% the thickness of earth's atmosphere. Now ...
3
votes
2answers
180 views

Realistic date and dimensions for a first future space shipyard? [closed]

If I try to imagine a time and scale (mass and size) for a first space shipyard mankind would build in next decades, how would it look like in a mostly realistic scenario? Ships I think of are more ...
2
votes
4answers
218 views

How do we know that distant stars and galaxies are real?

In some universe,with physical laws the same as in ours, our world is some kind of "lab environment". Our solar system is enclosed in a balloon-like sphere with a radius of a few light-days around the ...
1
vote
7answers
136 views

Would ai surpass humans in bipedal combat?

I was thinking of writing a story where a bipedal walker has the tactical, mechanical, and autonomy of a real person. Would it be viable to use an base ai that has already learned and trained to pilot ...
0
votes
1answer
116 views

What materials would be useful in constructing a Space Station?

For the obvious reason of weight, our modern space stations and satellites are made out of metal or lightweight compounds to reduce cost. In a quick Google search, about $20,000 per kg is the cost, to ...
7
votes
7answers
320 views

Perfect space faring race [closed]

I was wondering what the physical characteristics/traits are that would make an alien race perfectly adapted to exploring space. Assuming this race does not have FTL, but could reach potentially 0....
6
votes
4answers
397 views

Is a ring planet possible?

No planet in the center, just a large O shape made up of large chunks of rock that in and of itself itself orbits a sun, as if it were a planet (as distinct from a ringworld). I know most of the time, ...
1
vote
5answers
190 views

Should my Dyson Sphere be bigger? (Climate/habitable zone)

My world is a 1AU radius, 12000km thick Dyson Sphere with 6 equally spaced holes, 4 filled with water. The two main problems I have are gravity and heat. This question concerns heat and how to stop ...
1
vote
11answers
340 views

Why might a planet or solar system go undetected until discovered by a ship?

I have a scientific research vessel that is exploring an alien galaxy. I would like this vessel to detect and then explore a planet that was not previously known about, which means it (or potentially ...
0
votes
1answer
130 views

How can a planet have an atmosphere in a universe full of water? [closed]

Imagine a universe where the space is not empty (or almost empty) but somehow it's full of water or other liquid. How could planets still have an inhabitable atmosphere? What could make this "air ...
11
votes
5answers
830 views

Man-portable anti-satellite weapon

Man-portable air-defense systems have been around for decades, and so have been anti-satellite weapons. But while the former is a small, short range rocket, the latter is as big as a cruise missile. ...
10
votes
2answers
2k views

How would a corpse be preserved in outer space conditions?

Suppose you were puttering around the solar system and came across the remains of a luxury passenger vessel, the intergalactic equivalent of the Titanic, adrift about one AU from the sun. The hull was ...
50
votes
20answers
10k views

Could an advanced alien race prevent the death of the universe?

We all know that the universe is going to die one day: all the stars will die, all the black holes will evaporate and life will be gone. But hypothetically speaking, if a super advanced alien race (...
9
votes
3answers
209 views

Lifetime of the Moon's moon

Imagine if the Moon had its own moon. A moon (likely an asteroid) that lies within the Moon's Hill Sphere. I have read elsewhere about the fate of such a moon. Over time due to the Moon being tidally ...
7
votes
3answers
229 views

Is it possible for an organism to convert magnetic radiation into a sustainable energy source?

For backgrounds sake, let's say that there are large, and I mean large beings living underneath the icy surface of Europa. Now consider this excerpt from NASA's page on Europa: One of the most ...
3
votes
4answers
293 views

VERY dense asteroid belt - possible?

I'm making a game which takes place in an asteroid field that is very dense - I'm talking close enough that one is able to jump between asteroids (provided you have some sort of additional thrust ...
6
votes
6answers
442 views

What would happen to the Moon if it was lowered onto the Earth?

An absolute madman of a scientist tractors the Moon from it's orbit, and carefully lowers it through the Earth's atmosphere and gently brings it to rest upon the Earth's surface. There is no reentry, ...
-6
votes
1answer
135 views

Ordinary guns in space

Can you kill someone from an ordinary gun in space? Will it be able to shoot? I mean weapons like M4A1, pistols, rifles, shotguns, machine guns. How will they behave in open space? My thoughts are ...
16
votes
3answers
199 views

What software could I use to simulate my world's sky?

My protagonist is an astronomer in a fantasy world. Ideally, what I want is software where I can specify some properties of this planet, e.g. orbital and rotation period, nearby stars, number of ...
-3
votes
3answers
107 views

Gravity canceling space gun vs black hole [closed]

Not sure how to say this simpler, so we'll try shorter. We have a big space gun. It makes gravity not be there where it shoots. It shoots at a black hole. Does black hole go boom? And for the ...
28
votes
7answers
7k views

5km artificial planet, with same gravity as on Earth

So, the idea in a story is that in far far future there’s a trend that rich people, they are able to buy themselves planets. Tiny little planets with sizes 4-6 km (3-4 miles) in diameter. The company ...
12
votes
15answers
5k views

What kinds of weapons produce little or no recoil that could be used aboard a spacestation?

And by "Weapons" I mean ranged weapons specifically. Melee weapons would certainly be useful for close-quarters, but due to the range at which combat occurs in this question, I'm looking for ranged ...
-4
votes
1answer
230 views

Firing an AK-47 while anchored to the ISS [closed]

The Setup I magnetically anchor myself to the floor of the ISS. (yes I know there's no "floor", any wall will do) Then, I fire a 5-round burst out the airlock. The Question Can the recoil from ...
11
votes
3answers
379 views

How to estimate a star's heliopause?

Is it possible to calculate/estimate the size of a star's heliosphere? If so, how? I am working on a semi-near future, sci-fi novel. As part of the technology base, humans are able to travel between ...
10
votes
3answers
737 views

Can I monitor animal movements from space?

The Earth-like planet I'm working on is the culmination of years of labor by the galaxy's best scientists. It consists of fully artificial ecosystems, and is, for all intents and purposes, like Earth. ...