5
votes
1answer
36 views

Origin of the magnetic field of neutron stars

It seems a little counter intuitive that neutron stars possess such strong magnetic fields. Its electric charge is presumably zero, so however fast it spins, it shouldn't generate any magnetic field. ...
1
vote
1answer
72 views

If an object with mass were to somehow go the speed of light, would it destroy the whole universe?

Would an object with mass traveling the speed of light destroy the whole universe because it would have infinite energy / mass? According to ...
3
votes
1answer
62 views

Dark Energy Expansion

The new Cosmos extra features mentions that at about 6,771,500,000 years ago the universe began an accelerated expansion. How do we know this? What evidence do we have for this renewed and accelerated ...
1
vote
1answer
49 views

Could dark energy be negative gravity?

Main question: Could dark energy (the mysterious accelerating expansion of the universe) be explained by "negative gravity"? "Spin off" questions: Does antimatter have negative gravity? If ...
4
votes
1answer
48 views

Any cheap (less than 100 euro) telescope for observing Jupiter?

The moon is not challenging. I would like to observe the big planets and their rings.
1
vote
0answers
12 views

Why does Mars' experience an 'ice age' at high axis obliquity, when Earth experiences an ice age at low axis obliquity

This paper here goes into some detail about how Mars' experiences its own form of 'ice ages' on a quasi periodic basis driven by the wobbling of its axis. The main mechanism outlined is that the ...
1
vote
0answers
10 views

Is Mars' mantle homogeneous or heterogeneous and what might this say about mantle convection?

A supervisor of mine made an off-hand comment about the fact that Mars used to have plate tectonics, and there is evidence that Mars used to have plate tectonics, however now it does not. The theory ...
2
votes
1answer
36 views

What record do we have of the length of supernovas?

recently I heard an astronomer on the radio claim that the supernova we have observed in our own galaxy lasted about 6 months, while in distant galaxies they last about 7-8 months, due to relativity ...
1
vote
1answer
41 views

How does water exist within the frost line of a star?

My supposition is that within the distance of the so called frost line around a star, water in empty space sublimates, evaporates. I further suppose that this means that vaporized water is pushed to ...
1
vote
2answers
46 views

Stars in star clusters in SMC and LMC

Is there any catalog or any paper published in any journal that enlists the stars discovered under which ever star-cluster of Small Magellanic Cloud (SMC) they belong to? There is one for Large ...
2
votes
1answer
76 views

Sum of the Masses of All Moons in the Solar System

I'm looking for the total mass of the moons in the solar system in Earth Mass this would be include the 67's moons of jupiter, the 62's of saturn, the 27's Uranus and the 14's for Neptune. it's a ...
2
votes
2answers
44 views

How many stars are visible to naked eyes around Equator area?

In the best sky conditions, we can see about 44,000 stars in the sky. But what if I am located around Equator area? How many stars I can see? From what I know, the number of stars I can see should ...
0
votes
2answers
47 views

Is Mars visible from naked-eye from Michigan (47N, 88W) these days?

Is Mars visible at night sky of Michigan these days? I was trying to search for Mars from Michigan (at elevation of 30 deg and azimuth of 220 deg) around 11:45 PM with binoculars of 20x60 but didn't ...
0
votes
1answer
35 views

Distance of extra-galactic Classical Cepheids

There have been many questions and answers about finding the distance of a star from the earth. But as I did some research on the net, I found that we have specific approaches for finding the ...
-2
votes
2answers
55 views

One year on the sun [closed]

This might be a weird question, but I'll ask it anyway. If one year on earth is the time it takes for the earth to orbit around the sun, then (if it were possible for humans to survive on the sun), ...
7
votes
1answer
86 views

Is it safer to be near a star or a black hole?

If a star or black hole neared the solar system, which would do the least damage? For the sake of a good comparison, lets assume the candidate star is an "average" 5 solar mass star, and the black ...
7
votes
2answers
146 views

How are black holes doors to other universes?

I'm watching MIT OpenCourseWare lectures on general relativity and not too long into the first lecture the professor stated that the Kerr Black Hole solution allowed for travel between universes. How ...
1
vote
0answers
81 views

In 2016, the summer solstice will coincide with a full moon. How often does this happen?

I found that the solstices work on a 400 year cycle based on this. I can't find anything similar for the lunar cycle. Is there a formula I can use to calculate the date of the full moon?
2
votes
3answers
99 views

Where can I find a catalog of all stars in the Milky Way?

Is there a catalog of all known stars or brightest stars in our galaxy? Preferably with some sort of galactic coordinates instead of just night sky coordinates (right ascension, etc.) I'm trying to ...
-3
votes
0answers
60 views

How many planets do on average different star types support? [closed]

I'm working on a game which takes place in space. My team and I want to create a solar system generator for the game. We have selected 8 types of stars: White dwarf Red Dwarf Binary Super Red Proto ...
3
votes
2answers
77 views

What is the difference between gas and dust in astronomy?

Is there a strict difference between gas and dust? In Earthly environment most things become gaseous if heated enough. The temperature of interstellar medium seems to range mostly between 10 and 10 ...
1
vote
2answers
81 views

Outside of a Universe and its origin

Per the Big Bang Theory, the universe was formed from a dense singular point which existed 13 billion years ago and has been expanding ever since. This suggests that the point should have existed ...
1
vote
1answer
36 views

How might Thales have predicted a solar eclipse?

Thales of Miletus purportedly predicted a solar eclipse (most likely the solar eclipse of May 28, 585 BCE). The historicity of Thales' prediction can't be verified with any certainty given the ...
-1
votes
1answer
47 views

Does the sun have a protective shield

Does the sun have a protective layer that at least diminishes its radiation. I know the earth's atmosphere protects us from harmful rays. But does the sun have a sort of shield as well that if removed ...
1
vote
3answers
71 views

What do we mean by space is expanding?

I know this question had often been asked on Physics.SE as well as this site but I don't get them. What do mean when we say that space is expanding? I mean that space is no physical entity that can ...
2
votes
1answer
71 views

Is the expansion accelerating or Decelerating?

According to Hubble's Law, the farther a galaxy is, the farther it is moving away. But do we take into account the fact that we are actually looking in the past? For example, there are two galaxies A ...
0
votes
0answers
21 views

Coordinates of the Moon

How does one compute the right ascension and declination of the Moon at a given time (or for that matter, the altitude and azimuth)?
4
votes
4answers
125 views

Using the Sun as a Gravitational Lens

Can the Sun be used as a gravitational lens to achieve better telescopic viewing? Can this effect be practically used to view celestial objects?
0
votes
1answer
39 views

Can the Sun be used as a point source of light to achive better focus?

There's a limit to how well sunlight can be focused by a parabolic reflector or a lens because the Sun is not a point source. I wonder if the sunlight could be engineered to work as if it was (much ...
7
votes
3answers
207 views

How can the 13.8 billion years old universe have a radius of 46 billion light years?

The universe is about 13.8 billion years old. Assume at the big-bang it starts from a small region and the maximum possible speed according Einstein is the speed of light how can the universe got a ...
1
vote
2answers
52 views

Which is really larger, Big Dipper or Small Dipper, in 3D

If we take the convex hull of the 3D coordinates of the stars in Ursa Major and Ursa Minor: which hull has larger volume? This is meant semi-humorous but we might also learn some interesting points ...
9
votes
2answers
58 views

How does the evolution of a solar system not break the second law of thermodynamics?

Please forgive: I am a layman when it comes to physics and cosmology, and have tried finding an answer to this that I can understand, with no luck. As I understand it, the solar system evolved from a ...
0
votes
0answers
37 views

Connection between Earth, Moon, Theia, and astroid belt?

Are there other fragments aside from the Moon that resulted from the collision of Earth and "Theia" (as it's called in recent main-stream press stories)? And if not, why not? And what happened to ...
2
votes
1answer
62 views

Average amount of annual daylight at any place on earth

If this is the wrong group please direct me to the correct one. It seems intuitively obvious that the amount of daylight per annum should be the same for any latitude on earth. For example, 12 hours ...
1
vote
3answers
79 views

Why can we still see 10 billion year old galaxies?

I've never fully understood why we can still see galaxies that are 10 billion light years away. The age of the universe is calculated to be 13.9 billion years old and we live on a planet that it is ...
1
vote
1answer
52 views

If Mars orbited the Earth how distant would it have to be to cause the same tides?

If it were possible to replace the Moon with Mars, how distant would it have to be to essentially create the same oceanic tides as the Moon currently does? Mars seems to be roughly 3 times the mass of ...
0
votes
1answer
44 views

Orbital Elements Transformations

I'm a third year undergrad, and for the project I'm doing this summer, I need to figure out the Earth's position and velocity from the moon's point of view. From the reading I've done, it seems like ...
0
votes
1answer
59 views

Are there are any photographs online that approximate what the Milky Way looks like to the unaided eye?

I love seeing all the long-exposure photographs of the Milky Way, but I'm going to Cherry Springs State Park in Pennsylvania next month, and I'm wondering if there are any photos that approximate what ...
4
votes
0answers
46 views

Is it possible to have two objects moving by sum speed of light (c) in the opposite direction? [closed]

I am puzzled by this question, because by the laws between the two object the relative gravitation force should be infinite. Anyways we can take two objects where the sum of speeds are equaling c ...
2
votes
2answers
98 views

Is the Sun homogeneous?

Does the Sun have the same composition and density everywhee within it? How does it vary in other stars?
1
vote
1answer
41 views

What is $v_{GSR}$

In this paper ("The Apache Point Observatory Galactic Evolution Experiment: First Detection of High Velocity Milky Way Bar Stars") they plot and calculate $v_{GSR}$. $GSR$ stands for Galactic Standard ...
0
votes
1answer
30 views

How to calculate planet positions in (Rāśi) zodiacal signs?

I want to calculate planet positions according Specific Date, Time and place (Latitude & Longitude). Further clarification: I will input Date, Time and Place (with latitude and longitude) and ...
4
votes
1answer
105 views

How often do stars pass close (~1ly) to the Sun?

Interstellar exchange of massive objects is difficult across several light years. But as the stars orbit the galaxy the distances between them change. I don't find data for neighbor star distances ...
2
votes
1answer
64 views

What is the optimal escape trajectory from near a black hole?

Consider a space ship that is being drawn closer to a black hole. The crew begins to notice the effects, and discovers that they are nearing the black hole. They then manage to halt their ...
1
vote
1answer
13 views

Term for a momentary geometric pattern formed by astronomical objects

Few days back, the Pleiades, the Sun and the Moon were forming an almost perfect equilateral triangle. Is there a term that describes such momentary geometrical patterns? ...
3
votes
1answer
52 views

Is there a ceiling for stable L4 or L5 masses?

L4 and L5, the Lagrange points 60 degrees leading and trailing an orbiting body, are famous for being stable. I will label the central mass S, orbiting mass J and the L4 mass T: It's said S/J ...
1
vote
1answer
60 views

Why do we not send diggers to Mars if we think there's underground water?

A friend of mine asked me this question: If we have a guess that there may be underground water on Mars, why do we not send rovers with diggers? I do have a few ideas, but I want alternative ...
0
votes
0answers
10 views

Any new info about solar flares hitting the Moon added by the LADEE mission?

This article from 2011 mentions simulations about the sputtering effect caused by a solar flare hitting the Moon: "We found that when this massive cloud of plasma strikes the moon, it acts like ...
2
votes
1answer
52 views

Does Tobler's First Law of Geography Apply to Star Composition?

There is a principle in Geography called Tobler's First Law of Geography which states that "Everything is related to everything else, but near things are more related than distant things." Does this ...
2
votes
2answers
105 views

Why are spacecraft not air-launched from airplanes

I searched on the subject, thinking it could probably be cheaper to fly the spacecraft aboard a plane and then launch it from altitude. The only thing I found was this Wikipedia page, but it only ...

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