1
vote
0answers
7 views

What instruments/science goals have the highest priorities for a combined orbiter and lander to Europa?

A NASA mission to Europa seems to have a friend in congress. What would be the most important instruments and science goals for such a mission? Seismometry, radar, surface chemistry, a drill/melter, ...
2
votes
1answer
104 views

Theoretically, can a solar system evolve around lagrange points

My question is, during the evolution of a solar system is it possible to end up with a massive planet around a star with two small planets around their $L_4$ and $L_5$. Since we know it is not ...
2
votes
1answer
53 views

Is there a way to estimate the age of M dwarf stars?

Wolf 1061 (only 13.8 ly away) was recently found to have three rocky planets one of which is in the habitable zone. It was stated on the english wikipedia site that it has a very stable light curve ...
1
vote
1answer
29 views

When did the Scutum constellation receive its current name?

While cleaning my desk, I found an out of date star map (puts the cleaning into perspective, huh?) where the Scutum constellation is still referred to as Scutum Sobiescianum). This is the original ...
3
votes
3answers
52 views

Has someone ever captured footage of the collision of a meteoroid and a meteoroid?

For a video game I'm looking for footage of a collision of meteoroids or maybe asteroids, not planets. Even though I have searched for a while I couldn't find anything. So has anyone ever captured ...
2
votes
1answer
76 views

Is this the Cancer constellation?

In this photo taken by SpaceX during one of their Falcon 9 launches, I noticed a familiar group of stars but I'm not sure of what it really is. I encircled it in red, is this group the Cancer ...
3
votes
3answers
87 views

Are moons geologically active?

Are there natural satellites in the Solar System that are geologically active? This includes volcanism, existence and motion of tectonic plates, et cetera. Is it a common or a rather rare feature ...
7
votes
4answers
224 views

Why does it make sense to say the universe has no centre?

If we suppose we and everything in the universe is perfectly flat. That is, we have width and depth, but no height. And we are situated on the surface of a balloon blowing up with air and expanding ...
2
votes
1answer
78 views

Is the sphere of influence of our milky way's center super massive black hole same as the Milky way's radius?

The sphere of influence is a region around a supermassive black hole in which the gravitational potential of the black hole dominates the gravitational potential of the host galaxy(found it in wiki). ...
6
votes
2answers
167 views

Why do black holes choke?

I read that a black hole can sometime "choke" on a star: "...the disrupted stellar matter was generating so much radiation that it pushed back on the infall. The black hole was choking on the ...
2
votes
2answers
86 views

A beginner project in plotting celestial bodies in 3D coordinate space

As a data visualization task, I'd like to plot some celestial bodies in 3D coordinate space. I assumed there would be a lot of databases where celestial bodies are recorded along with an XYZ ...
5
votes
4answers
190 views

22nd is shortest day in some places, but the 21st is shortest in other places. Can this be true?

The Winter Solstice in the Northern hemisphere in 2015 is December 22 at 04:49 UTC. Where I'm located in Nova Scotia, Canada, that's December 22, 00:49 AST. And so I would say the shortest day of ...
6
votes
1answer
224 views

Can a star have a ring system?

I often hear about planetary ring systems, and even some moons might have them, but how about stars? Can a star also have rings?
1
vote
2answers
107 views

Can planets have orbits other than elliptical or circular orbits?

Can planets have orbits other than elliptical or circular orbits? All of the planets in our solar system have either a circular orbit or an elliptical orbit (perhaps like Pluto).
5
votes
1answer
193 views

If the Sun got larger, but maintained its luminosity, would the Earth get hotter or colder?

A recent question If the Sun were bigger but colder, Earth would be hotter or colder? asked - if the Sun got bigger and cooler, would the Earth heat up or cool down. I think the answer to that is ...
2
votes
1answer
113 views

Is Darkness Faster Than Light?

I've been looking around, and can't find a solid answer. Many websites say darkness is the speed of light due to the fact it is the absence of light, but other sources say otherwise, that in some ...
3
votes
1answer
77 views

If the Sun were bigger but colder, Earth would be hotter or colder?

That is the question. I know the concepts of luminosity $(L=4\pi R^2F)$ and the flow $F=\sigma· T^4$, with $T$ the temperature in its surface. But how I use that to know if the Earth would get warmer ...
2
votes
2answers
109 views

Would all neutron stars inevitably collapse into black holes due to quantum tunneling?

The materials inside a neutron star are densely packed (extremely close to each other) and as time goes by say about an eon later, most of the neutrons would eventually tunnel into each other and ...
10
votes
1answer
150 views

How quickly does a supernova heat up/expand?

Suppose there's a star out there that's a lot more massive than the Sun. Suppose further that orbiting this star is a planet not unlike Earth. Water, oxygen, civilization, and all. Now the star ...
6
votes
4answers
391 views

Do all planets have a molten core?

As we know, according to Wikipedia on Earth's inner core: The Earth's inner core is the Earth's innermost part and according to seismological studies, it is primarily a solid ball with a radius of ...
5
votes
1answer
52 views

Do the magnetic fields of stars and/or other planets reverse?

I've heard of the magnetic field of the earth reversing poles over the course of thousands of years but do stars and other planets (specifically gas giants) also experience this? If so how does it ...
8
votes
4answers
377 views

Do asteroids have a gravitational field?

I know that asteroids are huge chunks of rock, orbiting a solar system. Do asteroids have a gravitational field and do they gravitationally attract each other to form planets?
6
votes
2answers
68 views

Temporal path through Hertzsprung-Russell diagram?

Is there graphic of typical temporal paths that stars take through the Hertzsprung-Russell diagram?
0
votes
1answer
91 views

What is the difference between a neutron star and a white dwarf?

What is the difference between a neutron star and a white dwarf? I know that both are very dense even if they go through different phases.
3
votes
1answer
48 views

Why is there no time in the distance equation using Hubble constant, red shift and speed of light?

So I had some problem and I think I solved it, then I began to dig out things around it and I found some equations using red shift etc. to get speed of the object in Universe relative to us and then I ...
5
votes
1answer
110 views

Are there real uses of abstract algebra in astrophysics?

It is known that a physicist must have, at least in general, a good level in mathematics in order to research and understand other people's works. Linear algebra is a good example, as ODEs and ...
2
votes
2answers
72 views

Get date and time by position of the sun and the observer position

I am working on an astrology project (don't panic, my question is about astronomy or math), where I need to figure out some values by the longnitude of the planets. I have a program for this, the ...
5
votes
2answers
67 views

What exactly is 'eastward movement'

I am reading a book on spherical astronomy. Surprisingly, my problem is not with the mathematics. The author mentions several times words like 'eastward movement' and 'westward movement'. For example, ...
3
votes
2answers
105 views

At what rate are stars accelerating?

How fast stars accelerating away from a central point? Are they increasing in acceleration or decreasing? If possible could you please provide a plot of the acceleration of stars away from the central ...
2
votes
1answer
126 views

Do all planets rotate in the same direction in relation to each other?

In other words, does everything spin counterclockwise according to their axes (in relation to each other)? I suppose my question goes for stars, moons and other objects too. But then again, all you ...
1
vote
3answers
129 views

Why is it always planets orbiting stars?

In our solar system, there are 8 planets orbiting a star, the Sun. And I understand that there are about 500 confirmed solar systems out there. But why is it always planets orbiting stars? Why can't ...
10
votes
3answers
349 views

How Would a Neutron Star Actually Appear?

Having seen many pictures produced by artists of neutron stars and planets that orbit some of them, I was wondering how a pulsar would appear to a human being, in visible light (assuming the intense ...
1
vote
2answers
101 views

Can any stars ever form supermassive black holes?

I heard that most supermassive blackholes are not formed by stars – in fact, we aren't even sure how they're formed. But could a star, with enough mass and low enough metallicity, form a supermassive ...
3
votes
3answers
214 views

Why can't gravity repel things?

Gravity is the result of the curvature of space, so could the curvature actually send objects away from the source?
3
votes
1answer
55 views

trying to understand stellar nucleosynthesis

Trying to create a periodic table that shows "where" elements are made. For example big bang, cosmic rays, stars, supernovae etc...but reading a lot about gold,and other heavy neutron rich elements, ...
68
votes
2answers
7k views

How loud would the Sun be?

Sound can't travel through outer space. But if it could, how loud would the Sun be? Would the sound be dangerous to life on Earth, or would we barely hear it from this distance?
8
votes
2answers
124 views

How many stars are in the constellation Canis Minor?

I've read Wikipedia and found a list of stars in Canis Minor, and counted the number of stars in the list. I came up with 56 stars, a surprising number. I did some more research and found that Canis ...
1
vote
1answer
25 views

What visible differences do Geminids have to other meteors

Unlike all other meteor showers, which originate from comets, Geminids originate from asteroid 3200 Phaethon. Seeing a large number of meteors last night, I noticed they seemed to be much more green ...
11
votes
1answer
96 views

How is the first detonation in Supernove type Ia triggered?

Ok, I read about the Supernova of type Ia and I found out that there are two detonations happening. First one is in helium shell around the white dwarf and second one seems to be triggered by the ...
4
votes
2answers
91 views

Can dark matter decrease the Jeans length?

I am wondering if there are any models of interstellar cloud collapse out there which take dark matter into account. If dark matter has local perturbations or density fluctuations, then that may be ...
0
votes
0answers
23 views

What all application can be possible using the SiPM (silicon photomultiplier) and radiation detection in space? [duplicate]

I am searching about the radiations in the space, during my search I come across the SiPM by using that we can detect the radiations as per my understanding;But I am not getting that what type of ...
2
votes
0answers
70 views

Earth-Centered Earth-Fixed coordinates with respect to heliocentric coordinate system at vernal equinox

I am trying to calculate the position of a point on the Earth's surface with respect to the Sun's center at certain date at time. For what I am trying to do it is OK to ignore precession of Earth's ...
13
votes
2answers
142 views

What earth organisms would survive if they arrived on Mars?

Contaminating other planets is a concern in space exploration. My question is what organisms, or small collections of organisms, from earth would be able form a self-sustaining population on Mars? I'm ...
1
vote
0answers
68 views

How to get the longitude of the perihelion to find the Heliocentric Equatorial coordinates of a planet

I'm writing a program to randomly generate star systems and I have been having a difficult time figuring this out. I've found the equations I need to get the heliocentric equatorial coordinates, but I ...
6
votes
3answers
2k views

How long does a sunrise or sunset take?

From the time that the sun appears on the horizon, or meets it on its setting, to the time that it is fully visible, or no longer visible on its setting, how much time passes? Secondly, is there a ...
1
vote
2answers
123 views

Can earth escape sun's gravity with the help of a black hole heading towards our solar system?

To escape the Sun's gravity, the Earth would need sufficient amount of energy. Let's say a stellar black hole has entered our solar system and at a certain distance from earth, the black hole exerts ...
3
votes
2answers
155 views

Does spacetime return to being flat?

I wrote an experiment in HTML5 and Javascript to try to show what is happening to the curvature of spacetime as a body moves through a region. As time progresses, I'm using the ...
2
votes
1answer
87 views

Does gravity bend light, and how much time does it take for light to cross gravity of a Black Hole?

This is very confusing to me, so the question might be same. Please go through it, if required i will add more text. According to Einstein's theory of general relativity, photons are not technically ...
4
votes
1answer
77 views

How to cool down a moon?

I'm doing an Astronomy project and need to terraform a moon. It is about the size of Mars and orbits a gas giant which is at a distance of 1.28 AU of its star. I though about putting a sunshade at the ...
1
vote
1answer
66 views

Space Travel and length of time [closed]

So I read that if an astronaut travels at the speed of light and goes to a nearby star system , when he or she returns, he or she will have aged 10 years but 1000 years will have gone by on Earth. ...

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