4
votes
3answers
161 views

Did big bang happen only one time or it might happen again somewhere million time away from our observable universe?

We know, everything is in existence due to big bang from singularity. Time also started from that big bang point. So, did big bang happen only once or it might happen again somewhere million time ...
4
votes
2answers
416 views

Cosmic events as standard candles

Type 1a supernovae are used as standard candles. Are there other high energy cosmic events which can be used as standard candles. For example, collapse of neutron star into a black hole is also ...
4
votes
1answer
107 views

How often do meteorites hit earth

I heard of one that occurred in 2008 in the Nubian Desert in sudan, how often does it happen? Is there a catalogue of all hits or is it very rare? Related link (This is what inspired my interest not ...
4
votes
1answer
162 views

What lies at the center of a neutron star if any?

What does the current theory tell us about what is going on at the core of a neutron star, I'm expecting a black hole hopefully I won't be disappointed!
4
votes
2answers
313 views

Can we compress any object to create black Holes?

In general, when a star runs out of nuclear fuel, gravity gets the upper hand and the material in the core is compressed even further and creates black holes. I am clear till here. Now the question ...
4
votes
3answers
373 views

Is a black hole a perfect sphere?

I know all about how black holes form and why their gravity is so strong. However, is the gravity equally powerful in all directions? Will the event horizon appear as a perfect sphere?
4
votes
4answers
210 views

Inclination in Kepler's laws

So, you can determine the location of an object in an orbit at any given time via Kepler's laws, but how do you determine the orbital inclination at any given point in time?
4
votes
3answers
209 views

mountains higher than atmosphere

Is it theoretically possible that planets exist with mountains so high that their peaks overtop the planets atmosphere? And which physical laws are relevant for this question? I'm just curious. Thanks ...
4
votes
3answers
965 views

What are the most popular computer programming languages in observational astronomy?

I would like to work in the field of observational astronomy (not so much theoretical astronomy). I currently know two computer programming languages: C# and MATLAB. I have read that computer ...
4
votes
2answers
88 views

What are the objects that are visible from a city?

I live in a light polluted city of the northern hemisphere and I would like to know what I can see with my Skywatcher BK 707AZ2. I have already seen Jupiter (and its moons), Saturn, Mars, M45, the ...
4
votes
1answer
472 views

What percentage of visual stars are actually binary stars?

I know this is such a thing as a binary star where for example two stars rotate around a central point of gravity but to the naked eye are just a star. What I do not know is how common this is (...
4
votes
5answers
169 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)?
4
votes
2answers
183 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 ...
4
votes
1answer
135 views

Inability of Hubble to clearly resolve nearby celestial objects

The Hubble space telescope performs incredibly detailed and stunning imaging of celestial bodies that are many, many light years away, and yet when it attempts to image objects within our own Solar ...
4
votes
2answers
78 views

Why did the Chelyabinsk meteor explode?

In February, a meteor entered the Earth's atmosphere over Chelyabinsk, Russia and exploded, producing a shockwave blast that damaged hundreds of buildings around the explosion site in Russia. But why ...
4
votes
2answers
35 views

Capability of observing transits with terrestrial telescopes of various sizes?

I have access to my university's telescope, Dearborn Observatory, an 18.5 inch refractor on the shore of Lake Michigan, just north of Chicago (yes, it's an atrocious location, but the telescope still ...
4
votes
2answers
135 views

Why do planets move in an elliptical orbit? [duplicate]

I am a student of class 9 and recently came to know about kepler's law of planetary motion and got confused about the foci and elliptical orbits of planets and some stars.
4
votes
1answer
173 views

Why aren't new stars in Earth's relative proximity constantly discovered?

Okay, bear with me. In layman's terms: The estimates vary, but on a clear night, away from big cities, one can see up to 5000 stars in the sky. All those are in the Milky Way, but they're hardly ...
4
votes
2answers
91 views

Massive Nearby Stars

Is there a possibility that I will find records of stars with masses around 25-30 solar masses within 30 parsecs of solar system. If not, how far do I need to look?
4
votes
2answers
588 views

What happens when star spins too fast?

Some stars such as a neutron star can spin very fast around 600 times a second, wouldn't the star be ripped apart? Although the gravitational pull is very strong but gravity is the weakest of all ...
4
votes
1answer
318 views

Do the planets, asteroid belt, kuiper belt, and scattered disc lie on the same plane?

If not, do any of the four groups in the title lie on the same plane as other members of the group? E.g. does the asteroid belt lie on the same plane as the planets do?
4
votes
2answers
677 views

What's the mass of the interstellar neighborhood of the Sun?

What's approximatively the mass of the interstellar neighborhood of the Sun ? (for example the neighborhood of radius 50 light-years). Remark: The mass of the observable matter should be completed ...
4
votes
4answers
716 views

What is the exact mass of the Sun?

I am having trouble finding data on this. So far, I have found at least seven values: ...
4
votes
1answer
114 views

Why can't we detect water on Mars in the same way as in exoplanets?

Often I see news articles claiming astronomers found exoplanets with water. If we are capable of detecting water on such distant objects, why don't we employ similar methods to find water on Mars or ...
4
votes
1answer
115 views

How do telescopes “zoom” and change angle of view?

Images from the Hubble Space Telescope have widely different angles of view. Is this only the result of composing multiple images, or can the telescope itself change its "zooming" optically, ...
4
votes
1answer
41 views

Active Galactic Nuclei - categorisation on the basis of observer?

As we know AGNs are considered to be one of the most luminous objects to be found in the cosmos.Based on the observer, for instance on Earth, we categorize them on the basis of the angle between the ...
4
votes
2answers
490 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
2answers
205 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 Venus'...
4
votes
1answer
227 views

Lunar Soil: what are those “bumps” and how were they formed?

I was watching a video of the chinese lunar landing and saw numerous bumps in the soil. What are they? Is there any theory that explains how they came into existence?
4
votes
2answers
521 views

What is a wormhole?

I have learned that there are white holes and black holes in the universe, but I am confused as to what a wormhole is. Is it a tunnel that connects black and white holes?
4
votes
4answers
620 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 ...
4
votes
1answer
106 views

What's to be gained from the New Horizons mission once it's beyond the Kuiper Belt?

Now that we have seen what Pluto has to offer and New Horizons is headed to the Kuiper Belt, is there anything we can gain from the mission in interstellar space after it travels beyond the Kuiper ...
4
votes
2answers
187 views

What kind of things I could “see” with an amateur radio telescope?

There are apparently not many reasonably priced radio telescopes available for the amateur users. I only could find this one, which costs ~10 k€. Reading the page, I don't get a good overview what ...
4
votes
1answer
210 views

Mars night sky - how many stars visible?

How would the night sky look like from the Martian surface? Would there be more stars visible or less (compared to Earth)? Would they appear brighter/dimmer/same?
4
votes
3answers
340 views

Do objects look larger the further away they are, beyond z=1?

I stumbled upon this text which illustrates and says: We find that as the object is moved to higher redshifts its angular size first decreases (as naively expected) but soon begins to increase ...
4
votes
1answer
194 views

Is there a strong galactic magnetic field?

My main question is: Is there a strong galactic magnetic field, perhaps driven by the supermassive black hole at the center of our galaxy? I am also wondering if this field would be strong enough to ...
4
votes
1answer
154 views

Is it possible to steer the sight of a Liquid Mirror Telescope using a plain mirror scheme? If yes, why hasn't it been done?

I have read about Liquid Mirror Telescopes in a number of places, and according to these sources, a major disadvantage of these telescopes is that they can only "see" straight up. In a nutshell, the ...
4
votes
3answers
176 views

Strong force and metric expansion

If the expansion of the universe (the metric) continues (and perhaps is accelerating), in a very large but finite time the expansion of the metric will clash with the effects of the strong nuclear ...
4
votes
3answers
128 views

Are multiple satellites required to handle geostationary orbits?

Do geostationary satellites need to have the equator as the plane of rotation, and the earth's centre to be the centre of rotation? Can it rotate over, say, the Tropic of Cancer, focusing on a single ...
4
votes
1answer
249 views

Sun path at poles

At places other than the poles, the sun is seen to "rise" on the Eastern horizon and to "set" on the Western horizon. After a period of night, the sun "reappears" on the Eastern horizon. At the poles,...
4
votes
4answers
1k 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 ...
4
votes
1answer
145 views

Why is a meteorite impact on the moon visible as white light?

You can watch a video of a meteorite impacting the moon at the npr.org website. Why does the impact produce white light? I understand that the impact is like an explosion, but there is no air on ...
4
votes
2answers
125 views

Is the discovery of Alien or Extra Terrestrial Life a function of the science of Astronomy?

Is the discovery of Alien or Extra Terrestrial Life a function of the science of Astronomy? When i read astronomy articles on the search for new Planets or discussions on Mars a lot of the topic is on ...
4
votes
3answers
66 views

Is it possible that a star system ejects an object out of the galaxy?

I know it is possible that a star system ejects a planet out of the star system and the planets becomes rogue planets and orbit around the galaxy. Is it also possible that a planet gains enough speed ...
4
votes
1answer
161 views

Chemical reactions in white dwarf and carbon allotropes

White dwarfs consists mostly of carbon and oxygen. In my opinion, they are too hot to contain these elements in molecular form and hence chemical reactions does not happen (I think resulting CO2 will ...
4
votes
2answers
122 views

Why is space and time spoken of as one thing

I've never understood why it's spacetime and not space and time. In other words why aren't space and time spoken of as two different things. Can someone explain to me why this is
4
votes
3answers
86 views

Good textbooks for a descriptive astronomy course

Brief tale of woe My department at a small public university in the US has decided to begin offering a descriptive astronomy general education course for the first time in a couple of decades and we ...
4
votes
1answer
148 views

Could Venus or Mercury have a moon that we haven't detected?

Let's consider Mars' two moons for a moment. They're small, not even spherical, and most likely are captured asteroids. They weren't discovered until the late 1800's. Telescopes are much more powerful ...
4
votes
1answer
72 views

We are sure that there are no brown dwarfs closer than ______

I don't quite know how to word this question. How close could a brown dwarf be to us and have gone undetected until now? Or maybe, with what probability are we sure that there is no brown dwarf ...
4
votes
1answer
67 views

Sun as our Supergiant

Let's talk about the time when our sun becomes a supergiant. We know that our solar system may get destroyed or it may get affected due the large mass of the supergiant and also due to the large ...

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