3
votes
1answer
109 views

Would a Phobos full impact make Mars temporary habitable?

Due to tidal deceleration, Phobos is predicted to be destroyed by Mars in the next 30-50 million years either by collision or by breaking up in a planetary ring. If Phobos falls on Mars in one piece ...
4
votes
1answer
168 views

How small can a planet be and still have Earth-like gravity?

A planet made from denser material than Earth might have equal gravity to Earth but a smaller radius. How small can a planet be and still have Earth gravity? Ideally it should be habitable by humans, ...
6
votes
2answers
1k views

If Earth didn't rotate, would we feel heavier? [closed]

Suppose the Earth's rotation slowed for some reason. Would the lack of centrifugal force cause us to feel heavier than normal? Likewise, if Earth's rotation increased, would we feel lighter as ...
1
vote
1answer
62 views

Why is Mars' atmosphere so thin?

Is it because there isn't life to exhale enough oxygen and carbon dioxide? The size of Mars is about the same as Earth, so isn't there enough gravity to hold enough air?
5
votes
1answer
79 views

Would space-faring vehicles in interstellar space be in pitch darkness, show reflections from the nearest star or be bathed in light completely?

This is not a science fiction question, but I was considering the visual accuracy of ships in space depcicted in Battlestar Galactica and the like. They are always strongly lit. If they are in ...
2
votes
1answer
88 views

Hamiltonian of general three body problem

i try to extend my analysis from planar restricted three body problem to the general one. Is there anyone that can help me to find out the Hamiltonian for this prolem in cartesian coordinates? I ...
2
votes
1answer
48 views

Does Doppler shift affect apparent pulsar frequency?

We know that redshift and blueshift is the result of the frequency of light waves reflected or emitted by an object lengthening or shortening due to the relative velocity of the observer moving away ...
2
votes
1answer
146 views

How can the sun burn without oxygen?

Allright I am a 17 year old student, that only just figured out that the universe is amazing! Thanks to Dr. Neil Degrasse Tyson I raised a lot of interest in the universe. Due to his latest show ...
0
votes
1answer
37 views

is pan-starrs' data available to public users?

Anybody knows that? The data products are all images or star catalogs? This is the link: http://pan-starrs.ifa.hawaii.edu/public/
1
vote
1answer
65 views

What is visible light colour output of different stars?

I know the colours of the stars relate to their heat, however if I were standing on a different planet identical to Earth, but orbiting a blue Bright Giant or a Red Giant, or perhaps even a Red Dwarf, ...
3
votes
1answer
92 views

What determines which frequency range a radio telescope has?

My simple understanding is that a parabolic dish focuses radio waves to a receiver. It is obvious that any parabola focuses visible light and heat, so I assume that it focuses all radio wavelengths ...
5
votes
1answer
89 views

Is Sahara desert a good place to build radio/optical telescopes?

At least Atacama Desert of northern Chile is a good place to build telescopes. VLT and ALMA locate there. What about Sahara desert? http://en.wikipedia.org/wiki/Atacama_Large_Millimeter_Array ...
1
vote
2answers
117 views

Will a new planet form if Jupiter's influence on asteroid belt will diminish in a few billion years?

I know that tidal forces are pushing Jupiter farther from the Sun, but I couldn't find exactly the yearly amount. In a few billion years would this effect (and subsequent decrease in gravity pull) ...
1
vote
2answers
119 views

Is it dark inside a black hole?

Assuming you could be standing inside a black hole, would it be light or dark around you?
1
vote
1answer
32 views

Jupiter's magnetosphere interacts with the one from Saturn?

Jupiter's magnetosphere extends "seven million kilometers in the Sun's direction and almost to the orbit of Saturn in the opposite direction" and Saturn's magnetosphere extends towards the Sun on ...
3
votes
2answers
70 views

If the moon still had a magnetic field how long would have been possible to keep an atmosphere?

Let's assume the Moon had a considerable magnetic field to prevent the atmosphere dispersion caused by solar wind. Given the low gravity of the Moon, how many years would pass before all the gases (of ...
1
vote
2answers
92 views

Is the surface of Venus red hot?

I was wondering, is the surface of Venus so hot that it would glow red in the dark (e.g. on the dark side of Venus)? I am working on making a solar system simulator, and that would make for a great ...
3
votes
1answer
112 views

Could an asteroid impact cause radioactive fallout?

Could a (regional or global) fallout of radioactive material be a "bonus" disaster effect of an asteroid impact? My reasoning for how such a scenario maybe could be possible: A) Some asteroids maybe ...
2
votes
1answer
38 views

Is the local group bound to the Virgo cluster?

The virgo cluster is currently red-shifted by 0.003 according to Wikipedia; this indicates that the cluster is expanding. Will the cluster's enormous gravity eventually "win" and pull the milky ...
3
votes
5answers
123 views

Could there be life beneath the surface of Mars or moons?

I realize radiation and extreme temperatures would probably destroy life on the surface of most planets and moons, but could life exist beneath the surface (e.g. like earth worms on earth)?
1
vote
1answer
53 views

“Chain reaction” supernovae?

I know not all stars can "go nova", and that of those that do there are different types of novae, among which are some that aren't even explosions (at least not as we think of them), and that even the ...
3
votes
3answers
131 views

Does the Sun have hard radiation?

Does the Sun spread hard radiation waves around the Solar System? If so, why are we safe here (or are we even safe)?
5
votes
2answers
134 views

Has someone looked the other way?

I learned that gravity always pulls, it is always attractive. There is no antigravity, no "negative" mass. I also learned that most matter is dark, invisible. We know that because we see visible ...
-2
votes
1answer
78 views

Relation between position of stars and locations of gemstones? [closed]

A theory has been said that the patterns and positions help identify where valuable gemstones are hidden. I am wondering if this has any truth in it.
0
votes
2answers
58 views

Putting mass-luminosity relation and HS diagrams together leads us to a mass-age relation; so how do stars lose their mass over time?

I think that the title is completely clear, but here's an expansion: I was just reading about Mass-luminosity relation that says massive stars are more luminous than tiny ones. Well, let's talk about ...
1
vote
2answers
204 views

How are the speed, distance and time of India's MOM and USA's Maven Mars missions calculated?

How do the scientists calculate the correct time to launch the Mars mission so that the satellite travel time is less? How they are synchronizing the speed of satellite with respect to earth and mars ...
9
votes
3answers
327 views

Is it a coincidence that both the sun and moon look of same size from earth?

The sun is huge when compared to moon. Despite the huge difference in their size and distance from earth, Is it purely coincidental that they both look almost the same from earth?
0
votes
2answers
180 views

How can the universe be infinite?

I've heard from renowned astrophysicists that we don't yet know whether or not the Universe is infinite. How is that possible regarding the big bang theory is accepted (as they all do)? Are they ...
6
votes
3answers
232 views

What is a singularity? What is at the center of a black hole? Specifically regarding space-time

So because I can only really think of space-time in 2-dimensions like a sheet of something, my assumptions might be wrong to begin with. I was watching a YouTube video on black-holes and there was a ...
3
votes
2answers
82 views

Why is Mars considered the outer edge of the “goldilocks zone”?

In both books and documentaries I often see the Goldilocks Zone as described between Venus and Mars with the Earth "just right." This seems sort of ill thought out to me, because it assumes that ...
4
votes
2answers
112 views

Does the earth's atmosphere act as a spherical lens and refract light from space?

If so by how much does it "spoil" the view of stars and galaxies etc. Is this error noticable, when compared to pictures taken from outer space.
1
vote
3answers
166 views

Why is iron responsible for causing a supernova?

Why is the element iron responsible for supernova? Can any star create more element than iron within the span of its life? I understand that when star dies due to supernova, other elements are ...
4
votes
1answer
96 views

Maximum Amplitude of a Lissajous Orbiting Object in a L4 or L5 Position

I stumbled on The Lagrangian points during some wikipedia reading. After looking at the gravity contours, I naturally come to the conclusion that the L4 & L5 should have a wave pattern and then ...
6
votes
1answer
347 views

Why is the solar system often shown as a 2D plane?

Whenever I have learned about the solar system I always see the orbits displayed as a virtually flat plane. Are all of the orbits in the solar system really like this? If so, why? It seems like a ...
1
vote
1answer
112 views

Please Guide me to buy my first Telescope [duplicate]

I am a beginner and I've planned to buy a telescope(Newtonian reflector)for viewing planets and deep sky objects. As far as I know the most important factor to get a brighter view is that the ...
3
votes
2answers
111 views

What is the term for a star swallowing another star?

A star A goes through the body of another star B, or is swallowed by B. There is no tidal disruption. It sounds like kerzan. Does anybody recognise this pronunciation?
2
votes
1answer
168 views

Black Hole / Hawking Radiation: Why only capture anti-particle?

I may have some specifics wrong here. If so, don't focus on those. Just focus on the general thrust of my question. I "understand" (cough) that particle/anti-particle pairs form spontaneously in ...
7
votes
1answer
1k views

Are satellites orbiting around earth visible to the naked eye?

I was just lying under the sky trying to possibly see some meteorites, unfortunately never seeing any I might add, but I saw three objects all moving at about the same speed( all at different times). ...
2
votes
1answer
64 views

Choosing a diffraction grating

I am interested in doing some solar spectroscopy on my own for fun. How do I go about choosing the appropriate diffraction grating?
3
votes
2answers
96 views

Questions about time and space (from beginner)

To be honest my knowledge about astronomy and related physics is close to zero. However, since I studied math a bit, I would like to ask a couple maybe stupid questions, which I am curious about and I ...
3
votes
1answer
106 views

Which type of telescope should I make?

I am not very much interested in observational physics but I just like to look at the night sky. It gives me a lot of inspiration. So, i was thinking about making a telescope for basic observations. I ...
3
votes
1answer
60 views

How to use a telescope to find a specific celestial body?

I am a beginner interested in astronomy. I bought a Celestron AstroMaster 130EQ telescope. It's a Newtonian Reflector and it's not computerised. I did manage to see the Moon in some magnifications but ...
3
votes
2answers
90 views

How and when did we learn about the universe?

I'm 13 - I'd like to know how we found/discovered important details about the Universe. I know we have found many different things about the Universe, but when did we find how amazingly large the ...
1
vote
2answers
58 views

How are East and West defined on other bodies of our solar system?

I noticed that East and West appear swapped on maps of the Sun, even though the Sun rotates around its polar axis in the same sense as Earth. See for example below Sun disk with a Venus transit ...
1
vote
1answer
47 views

Will we ever end up in the black hole? [duplicate]

Since we are spiraling around the black whole will we spiral into the black hole?
2
votes
3answers
286 views

First night on a telescope questions

So I recently got into astronomy and I am using my fathers old Meade EQ1-B reflector telescope. This is my first night using it and I have come across a few questions. To begin, the telescope was left ...
5
votes
1answer
72 views

What was the age of the universe when the average density was one atmosphere?

How long did it take after the Big Bang for the average density of the universe to reach one Earth atmosphere at sea level? How about the density of water? Is there a chart of densities that relate to ...
5
votes
1answer
435 views

Best telescope for the viewing of Nebulae, Stars and Planets

So, I am a 15 year old interested into astronomy. My father used to have a reflector telescope, but was never so serious about it that he could recommend me a good telescope. I am looking to buy a ...
1
vote
1answer
31 views

Assumption of our universe being the surface of a 4-D sphere in order to describe relative uniformity in the cosmic microwave background?

It seems as if this is necessary to assume in order for the CMB to make an sense. Otherwise, an instantaneous infinite Euclidean space model would work. The issue is, with any visualization of the Big ...
3
votes
2answers
87 views

Stellar mass of galaxies

Given the magnitudes (in the i-band) of certain galaxies, I would like to calculate their stellar mass (in terms of solar masses). So far, I have calculated their absolute magnitudes and gotten to ...

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