1
vote
1answer
46 views

Dark matter inertial mass

We know the existence of dark matter because we can test its gravitational mass (e.g. in gravitational lens) but, since we cannot see this matter, how we can be sure that it has an inertial mass, and ...
0
votes
1answer
30 views

At the moment of total solar eclipse what are exact distances of Moon & Sun to the Earth

By total eclipse I mean the Moon and Sun are seen equal in size, neither of them is bigger. For example, the Moon's average distance is 384000 km and the Sun's average distance is 149.5 million km. ...
0
votes
2answers
107 views

Why Milky Way and Andromeda are being drawn together if there was 'Big Bang'?

Scientists used to use following reasoning: most galaxies are red-shifted $\implies$ there was a 'Big Bang' Why this is being considered valid since not every galaxy has such property?
0
votes
1answer
32 views

Calculating Right Ascension and Declination from Latitude / Longitude / Time

I have a latitude / longitude / time of a location on Earth, I need to calculate the Right Ascension / Declination that's overhead at the time provided. So far I've found out that Right Ascension is ...
1
vote
2answers
47 views

Are Wikipedia's sun ecliptic-coordinate formulae accurate?

I'm creating a C++ program that calculates the ecliptic coordinates based on the formulae from Wikipedia But, my calculations appear off. The mean anomaly for today, for example, should be ...
0
votes
0answers
15 views

What is the boundary of the space or can the space around us has limits? [duplicate]

When i see this vast universe, I usually had a question in my mind that, what is the limit of the space? I know its childish, but I have this curiosity.
2
votes
0answers
25 views

What explains the distribution of new impact craters on Mars?

24 minutes into this van Karman lecture by Dr. Tamppari, the slide below is shown with symbols for transient events on Mars. Red dots represent meteoroid impacts which have occurred while MRO has been ...
1
vote
1answer
30 views

Could the Sun's bending of light be measured on photographic plates before Einstein's prediction?

It was predicted from Newtonian physics already in the 18th century that gravity should bend light, but not by as much as general relativity predicts. This was first confirmed during a solar eclipse ...
2
votes
1answer
45 views

If a star were to suddenly lose nearly all of its stored heat, would it be able to return to its normal state? [closed]

If not, would it be possible to approximate the maximum heat energy a star could lose before the change became irreversible?
0
votes
1answer
50 views

Initially non-flat space-time makes dark matter obsolete$\dots$

After the Big Bang, dark matter clusters and build the seeds for visible matter, that then forms stars, planet, you, me, everybody... But do we really need dark matter to build cluster first. What if ...
1
vote
2answers
79 views

Is the motion of the Sun around the Galaxy a result of gravitational pull?

Does the orbit of the sun (and other stars within the Milky way) around the galaxy result directly from radial gravitational force toward the objects in the center of the galaxy, or is there ...
4
votes
4answers
188 views

Which Planet/Star is it?

I live in north India. About 24° latitude. I can see a very Bright star in sky. Its towards east and high up. Is it Venus , Jupiter, star or anything else? Its not Sirius. I used Orion belt for that. ...
6
votes
2answers
177 views

Would being ejected from the Milky Way Galaxy have any major impact on life on Earth? [duplicate]

I was reading about the impending collision of our galaxy with the Andromeda galaxy, and learned that there is a small possibility that our solar system could be ejected during the collision. ...
0
votes
1answer
99 views

Why are planets round?

I was studying our solar system and all celestial objects are depicted as round objects, including black holes.. worm holes as hollow cylinders as a pathway across two universes.. even the galaxy is ...
0
votes
1answer
71 views

Can a human land on Mercury? [closed]

Can a human in a normal astronaut suit designed for the moon, land on Mercury and walk on it's surface. If not what would happen to him/her?
3
votes
1answer
47 views

Solar / lunar positions in ECEF using SOFA C libraries

I'd like to calculate the positions of the sun and moon in the ECEF coordinate system using the SOFA (http://www.iausofa.org/current_C.html) libraries given a Julian day input. So far, I've got this ...
1
vote
1answer
40 views

Why is declination positive in the northern hemisphere?

Simple question -- why is declination positive in the northern hemisphere? Seems like it should've been called "inclination" since the word originated north of the equator.
0
votes
1answer
78 views

Is the Drake equation based on a logical fallacy? [closed]

I often wonder why the Drake equation gets taken so seriously and why popular scientists in general say "it's probable' life exists elsewhere in the cosmos. My problem is that the mechanism for ...
0
votes
1answer
89 views

Sun like star in our milkyway?

Is there any popular star or one which we can see with our naked eyes in our milky way that is atleast 90% sun-like(mass,radius,spectra,luminosity).The important thing is it must not be a binary. Its ...
4
votes
1answer
50 views

How Soon Could a Waxing Crescent Moon Be Seen?

Question: Apart from a Solar Eclipse, How much time is needed until a Waxing Crescent Moon be seen following a New Moon? Would the time of year be significant? The Vernal Equinox + 1 Month. ...
0
votes
1answer
40 views

Parabolic or hyperbolic trajectories

According to Newton's laws, the trajectories for the two-body problem are conics: either ellipses, or parabolas or hyperbolas. Of course periodic motions require Ellipses and in the Solar system these ...
3
votes
2answers
127 views

Photon Paradox?

Imagine a photon reaching the Hubble Space Telescope today had originally been emitted from a star in the early universe 13 billion years ago. Einstein’s Special Relativity tells us, traveling at the ...
5
votes
1answer
83 views

How big do comets get?

If my understanding is correct, Chury, the best explored comet so far is rather on the smallish side as comets go. Most comets observable with naked eye were so because they flew close to Earth, not ...
0
votes
1answer
73 views

How does dark matter interact with black holes?

Is dark matter trapped near / in black holes, like regular matter is, or does something different happen with dark matter?
-1
votes
1answer
83 views

Could the sun burn a human floating next to it? [closed]

If a human was naked a few hundred feet from the sun, floating, with no atmosphere, not affected by the vacuum of space or UV radiation. Would the sun burn him/her? Or not have any effect?
4
votes
1answer
118 views

Is there a map of the galaxies?

I see that there are many maps of a single galaxy, the Milky Way, showing the positions of the stars within our galaxy. I could not find a map of Galaxies, however. Is there such a map? In lieu of ...
0
votes
1answer
66 views

Is it possible to know if a planet is located in the Habitable Zone knowing it's properties?

Is there an equation that can give me the possibile distance of the planet from his star knowing planet's temperature (or other datas)? I found this method for calculating the Habitable Zone but ...
0
votes
1answer
98 views

Cluster of fast moving stars

We live in NW Tasmania in a country town and tonight out walking I pointed out a long cluster of stars to my sister as they made an unusual shape but then we realised they were moving really fast - we ...
0
votes
0answers
22 views

Do accretion disks of black holes generate magnetic fields? [duplicate]

When a black hole's accetion disk rubs against each other it creates a static charge . Since the disk is in continual motion does it give rise to a magnetic field?
0
votes
1answer
33 views

Is there a strict chronological order that determines the shape of galaxies?

Assuming no collision happens, do all elliptical galaxies eventually become spiral? also when a galaxy becomes spiral or barred spiral, can it switch between these shapes or is it set forever?
0
votes
1answer
26 views

Declination change due to precession

I have this problem: I want to calculate the declination of the star in the year 5000. And I know RA (right ascension) and Dec (declination) of the star right now. How can I calculate it using ...
2
votes
1answer
57 views

Can we apply Kepler's law of planetary motion to the moons motion around the earth?

I have been trying to understand Kepler's law of planetary motion for a while. So I was thinking, if it would even apply to the moon orbiting around the earth. Does the moon too orbit in an ellipse ...
0
votes
2answers
43 views

Approximate distance from Earth to Mars at a given moment with reasonable (+/-100km) accuracy?

I've been scouring the internet for a straightforward way to approximate the distance between Earth and Mars at a given time. I hope to achieve an accuracy of about 100km.
0
votes
0answers
35 views

Use every of our TV dishes as a radio-telescope?

Does anyone knows if it were possible to use all the ground bases TV dishes lots of people have on their homes be usable as a radio-telescope if we put all of them together? Would this have any ...
0
votes
1answer
65 views

State vectors of “interesting” multiple stars

I'd like to show a demonstration of Runge Kutta integration of real systems using examples of interesting multiple stars, where "interesting" means you can see through a small telescope that they are ...
1
vote
2answers
179 views

Why is the universe full of spinning objects?

Almost all celestial objects are rotating in some way about their axes. Why is this and should we expect the rotation to slow as the universe ages?
1
vote
0answers
30 views

Pyramid shaped observatories

There are some pyramid shaped observatories around the world, like the Solar Lab Pyramid (1) in the Canary Islands or The Pyramid International Laboratory (2) in Nepal. (1) (2) I was wondering, ...
0
votes
1answer
44 views

Why does the eclipse in this video look annular?

In this article about the AS870 flight that flew through the umbra of the March 8-9 2016 solar eclipse, there is a link to a YouTube video showing the eclipse recored by a handheld camera in the ...
0
votes
1answer
102 views

Does Pi change when gravity changes [closed]

Will Pi have the same value on the surface of say Jupiter, compared to the value of PI on Earth. Or does Pi vary with gravity?
0
votes
1answer
70 views

How to determine the mass of a runaway star?

I would like to know how do astronomers estimate the mass of a star that has been ejected from its galaxy. What kind of accuracy can be achieved?
1
vote
2answers
30 views

How does gravity affect spacetime [closed]

Scientists say that gravity warps space and time. They also say that the more gravity there is the slower time moves. Why and/or how does gravity do this.
1
vote
1answer
48 views

Light that travels eternally because of inflation?

What happens with electromagentic waves that are emitted into intergalactic space, but reach not any object because of inflation? Lets assume that photon A and photon B are emitted. Photon B hits ...
5
votes
2answers
141 views

Are all the photos of the universe really so colorful or is it just visual effects that are added later?

Do the colorful pictures of the universe show how it looks like that in reality or is it just a visual effect that is added later.
0
votes
1answer
154 views

What are the 10 most abundant elements in the universe by number of atomic nuclei?

I've seen websites that show the ratios of the 10 most common elements but they compare them by relative mass. I think it's more interesting to know the relative abundances of atomic nuclei because ...
4
votes
4answers
600 views

How could a neutron star collapse into a black hole?

White dwarfs usually do not collapse, as they have electron degeneracy pressure due to the Pauli exclusion principle. However, if one accretes mass beyond the Chandrasekhar limit, it is energetically ...
1
vote
0answers
50 views

Obtain tangent point (origin) of the Standard Coordinates system

In a previous question (Transform pixel coordinates (in FITS file) to equatorial), Rob supplied a great source that describes the process of obtaining celestial coordinates for objects in an observed ...
1
vote
2answers
31 views

What's the proper terminology for nebula clouds?

I'm writing a research paper over outer space (yeah, yeah, broad topic) and I'm wondering what the proper terminology for nebula clouds is. This is an excerpt from my paper showing how I'm going to ...
1
vote
2answers
57 views

Measuring star distance by parallax using a small telescope

I was wondering if it's possible to measure star distance using parallax at home with a small telescope (Something like a 3-inch reflector)? Or is this not really practical?
3
votes
1answer
56 views

What is the distribution of organic compounds in the Milky Way Galaxy?

I imagine the answer is unknown for the entire galaxy, but I'd appreciate a notion of the scales and locations of regions where astronomers have ventured at least a guess as to the distribution of ...
1
vote
1answer
30 views

Transform pixel coordinates (in FITS file) to equatorial

Say I have a FITS file with an observed field of stars, each one with x,y coordinates given in pixels. Assume the image is aligned so that the x axis is the right ascension, and the y axis the ...

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