7
votes
3answers
253 views

Can impact craters on the moon act like giant radio telescopes?

Could large craters on the moon be used as reflective lenses for radio signals? Acting like a large radio telescope reflecting radio waves to a satellite positioned over the crater.
1
vote
1answer
68 views

Why do we not find larger quantities of helium in the Sun's atmosphere?

The Sun currently shines because H is being burned to He, and it has been doing this for about 4.57 Ga. But when we analyze the Sun's atmosphere, we do not find unusually large amounts of He. Why not? ...
25
votes
4answers
5k views

What would happen if an ice cube is left in space?

Recently I boarded a flight and noticed Outside air temperature as -53°C at an altitude of 36860ft(11.23km). I don't know what causes such a freezing temperature in that altitude but was wondering ...
4
votes
1answer
98 views

Cooling of stars

If all stars suddenly stopped producing heat (or heating up) which stars would cool to absolute zero first and how long would it take?
2
votes
0answers
52 views

How exactly can the hypothetical conformal invariance of the CMB spectrum be established by analyzing tensor modes?

In the introduction of this paper at the top of p11, it is mentioned that a hypothetical enhancement of the scale invariance of the CMB spectrum to conformal invariance could potentially be ...
-2
votes
1answer
111 views

Does science need support from religion or philosophy to explain the creation? [closed]

Science is trying to explain how the universe is made. The beginning of the universe explains the Big Bang theory. But what happened before Big Bang? Science cannot go before that. So, does this mean ...
1
vote
1answer
125 views

Are neutrinos affected by gravity fields?

Am asking if a neutrino can be pull by the gravity field of a quasar or a black hole, assuming the neutrino have momentum. It could be possible in the that a neutrino can orbit a black hole at an ...
3
votes
2answers
96 views

which or what kind of star has a very stable luminosity?

I mean those kind of stars should be very stable and barely have activity. Their light curves should be very very flat. Our sun, as a G type star, are not so stable. At lest there are lots of ...
2
votes
1answer
134 views

In the end what is the ultimate matter/element in the universe, due to fusion process in stars?

We know that, in stars, hydrogen is used by the stars and due to the fusion in two hydrogen elements we get helium -> Carbon -> Oxygen ->Other elements -> Iron -> then Super/Hypernova. If everywhere ...
-3
votes
1answer
89 views

Big Bang Thoery, what triggered it and why [closed]

Given the vast infinite nature of universe, billions of worlds, distances and masses that we cannot comprehend, do you feel Big Bang theory is inadequate and in some ways tells you that it was all ...
3
votes
1answer
128 views

How would Alpha Centauri A appear from the surface of Alpha Centauri Bb?

I'm trying to imagine what a hypothetical observer on the surface of Alpha Centauri Bb would see in the daytime sky. I know it would vary depending on the orbit of b around B, as well as the position ...
1
vote
2answers
60 views

Do contracting objects show redshift?

If we consider a point on the central part of a contracting object as observed from earth, the point is continuously moving away from us as the object contracts. Moreover, light emerges from a deeper ...
5
votes
3answers
244 views

What shape are black holes theorized to be?

I have always been curious about what black holes (or their event horizons) would look like if we could directly observe them. I notice that they tend to be depicted as flat holes in space but it ...
0
votes
1answer
44 views

Sources of astronomy-related dataset?

I'm doing a project for a statistics class, and I thought it may be interesting work with a dataset associated with astronomy. I know absolutely nothing about astronomy, unfortunately, and I wouldn't ...
1
vote
2answers
126 views

How can a Blackhole have mass?

It is said that in Blackhole 100% part of the mass is getting converted into energy. Then how come Blackhole is having mass ?
3
votes
1answer
189 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 ...
5
votes
1answer
345 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
2k 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
73 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
147 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
2answers
135 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 ...
3
votes
1answer
93 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 ...
5
votes
2answers
468 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
132 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
111 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
126 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
118 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
180 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) ...
2
votes
2answers
175 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
44 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
94 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
157 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
384 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
46 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
134 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
116 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
160 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
151 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 ...
-3
votes
1answer
99 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
123 views

Putting mass-luminosity relation and Hertzsprung-Russel 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
318 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 ...
10
votes
3answers
514 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?
1
vote
4answers
346 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
356 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
123 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
194 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
597 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
124 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
700 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
188 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 ...

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