Questions tagged [solar-system]
Questions regarding the Sun and objects orbiting it.
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What's the minimal argument I can give to reject The Geocentric Universe?
I'm new to Astrophysics, So pardon me if you find it silly to ask. I was just started reading about the basics of astrophysics. I read about the Greek Tradition, the concept of a geocentric universe. ...
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1answer
55 views
What is the Milne-Eddington Approximation?
In this paper: Planet temperatures with surface cooling parameterized it states in the "radiation model" the following:
The Eddington–Milne approximation relates $T_0$ and $T_e$ through the
...
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Are interstellar meteorites more common on the moon's polar regions?
Given that the rocks of the solar system mostly travel on the disc, is there any considerable probability that impacts on the moon coming straight up and down can be interstellar rocks?
If axis-...
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Observing the motion of the solar system and galaxy through space?
This is very perplexing.
Conditions:
planets are moving around the sun (solar system)
solar system is moving as part of the galaxy
the galaxy is moving through space on some axis
galaxy is part of a ...
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Why do the asteroids orbit the Sun in roughly the same plane as the planets?
The asteroid belt between Mars and Jupiter is an extremely active environment (on an astronomical time scale) where collisions between 10km radius bodies occur every $10^7$ years, according to ...
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How can I find the width of an orbit knowing some values?
I need to find the width/x-radius of an orbit, which is ellipse shaped, knowing variables like the orbit's length(perihelion + aphelion in this case) and the eccentricity. I am not sure if this is ...
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Why won't the Sun set for days at N66.2 which is below the arctic circle?
Correct me if I am wrong, but if we count sunsets by the center of the Sun apparently crossing the horizon then the Sun is supposed to set every day at latitudes under the arctic circle. (Yes if you ...
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How to calculate center (not focus) of planetary orbit?
I'm developing a website showing the movement of Solar System planets according to the passage of time. I'm using this reference to calculate all the necessary orbital parameters.
These are two images ...
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What pulls the Sun above the galactic plane and pulls it below the galactic plane?
Since the sun climbs above the galactic plane and it even dives below the galactic plane we can't deny that it wouldn't climb upward unless there is something above the galactic plane that pulls it ...
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Could our Sun be the product of an ancient stellar collision?
The canonical model for the formation of the Solar System involves the gravitational collapse of a nebula into (perhaps) several stars across several light years. Is it possible that two or more of ...
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1answer
244 views
If Planet Nine indeed exists, how large a impact event there should be to be seen from Earth?
Recently I've found this news article, A meteorite crashed into the Moon during total lunar eclipse in January, about a collision into the moon that happened while a lunar eclipse was under way. ...
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How to measure mass of planets' core from orbit
I am told in an astrophysics lecture the following.
The mass of Saturn's core was measured by Cassini when it completed its final flyby between the rings and the planet itself. It was also found that ...
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What is the thickness of the Solar System disk?
What is the thickness in AU of the all planets' orbital plane height combined in the Solar System?
Excluding Pluto.
Looking for h
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1answer
570 views
How much matter was ejected when the Solar System formed?
Assuming the accretion disk model for the formation of the Solar System, the most important problem, according to wikipedia, is "how the material, which is accreted by the protostar, loses its ...
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1answer
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River-like artifact in perseverance rover's photo of Mars
Good to know that perseverance rover has touched the surface of Mars finally. We will have nice new opportunity window for exploring our closest "friendly" planet of solar system.
Here's one ...
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How is it possible for a collision to be responsible for Uranus's axial tilt?
I realize that the collision explanation is in any case highly (purely?) speculative, but I'm curious how it would work. If Uranus is a ball of gas, why wouldn't any colliding object just pass ...
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North Stars of each Solar system planet?
What are the North Stars of each individual body points too?
E.g.
Earth points to Polaris.
Mars points to Deneb/Alpha Cygni.
What about Sun, Mercury, Venus, Moon, Jupiter, Saturn, Uranus, Neptune, ...
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Why is Mercury's Density So Low?
I know the title sounds odd. You might be thinking "Doesn't Mercury have the highest uncompressed density of any terrestrial planet? Much higher than a planet its size normally should have?&...
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Sample bias' contribution to “Planet 9” hypothesis, why was this not thoroughly addressed before?
Science Claim for giant 'Planet Nine' at Solar System's edge takes a hit
arXiv No Evidence for Orbital Clustering in the Extreme Trans-Neptunian Objects
The brightness of distant solar system objects ...
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1answer
180 views
Calendar year versus Tropical year
I'm wondering about the convention for keeping the calendar year in sync with the tropical (exact) year. I did a preliminary calculation, but, it seems to be out by more than the average calendar ...
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2answers
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What are the Time Zones on Mercury?
I normally post on worldbuilding, but this question is merely about facts of a planets orbit and spin. I am trying to figure out how time periods work on Mercury to possibly make a worldbuilding guide ...
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1answer
58 views
Recently, the most distant object in the solar system was discovered. How was this accomplished?
It was recently announced that the most distant object in our solar system was discovered. This object averages 132 AU from the sun. The object, initially named Farfarout, was estimated to be 400 km ...
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Do moons of rocky oblate planets migrate to low inclination over time? If so, does the time it takes depend on the Moon's size?
Discussions elsewhere suggest that this happens and that smaller moons would tend to low inclination with respect to the planet's equator faster than larger ones.
For example, Mars' small moons are ...
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Do the orbits of planets change? Where is the data for this?
Everything in the space is moving all the time.
Do the orbit of major Solar Systems planets, Mercury to Saturn change? Just like Moon's orbit around Earth changes.
How often, how small or big is the ...
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115 views
Feasibility of Grand Tack Hypothesis
Something I've been wondering lately is how much the grand tack hypothesis stands up to present scrutiny. While the grand tack proposes that Jupiter and Saturn were caught in a 3:2 mean-motion ...
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What is the antonym of “closest approach”?
The distance from Earth to Mars, during their closest approach, is about 55 million kilometers.
At their furthest apart, that distance would be about 401 million kilometers.
Distance
at closest ...
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50 views
Is the mass of Kuiper belt dominated by large objects?
There is a problem in my example sheet trying to teach me distributions. My result is that Kuiper belt objects are dominated by large mass objects. Is this supported by observational evidence?
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Do some comets spin? If so, how fast?
The GIF below is copied from my question earlier What might a CN filter be in the context of comet watching? Is it showing dust, or gas, or something else? where I'd said:
In this post on the website ...
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1answer
216 views
Which will destroy the Earth first: the Sun or Jupiter?
The sun is expected to grow in brightness over time, slowly heating the Earth until the oceans evaporate, leaving the planet uninhabitable.
Jupiter is the source of the largest perturbations to Earth'...
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Sun's and planets' inclination to the Invariable plane
What are the inclinations of all major Solar system planets (Mercury to Pluto) to the invariable plane? Looking for accurate data calculated on them.
Also, What is the inclination of the Sun to the ...
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1answer
396 views
If the fifth gas giant in the early Solar System was completely ejected, where would it be now?
I've read about the possible 5th gas giant in the Solar System, and about its ejection about ~100 million years after the formation of the Solar System. However, I have not seen anything about its ...
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What if a planet or another star or ¨sun¨ collided with our sun? [duplicate]
Stellar collisions are a well-studied phenomenon in Astronomy, albeit mostly theoretically. In some cases the merger of two low-mass stars can result in a new star plus new planets around it.
But what ...
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Calculating the Angular Momentum of a planet
I want to calculate the Angular Momentum of any planet at any point on the orbit around the Sun.
Example: I want to calculate the Angular Momentum of Pluto today, on Jan 27, 2021 00:00:00 Hrs
Where ...
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What is the upper bound of number of stable interacting stars in a star system?
I remember very well reading in an article that it's impossible to have a stable star system of 4 or more stars. The article justified its claim discussing about the complexity such systems would have ...
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1answer
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Moment of inertia factor of Venus and Pluto
Wikipedia's Moment of inertia factor begins:
In planetary sciences, the moment of inertia factor or normalized polar moment of inertia is a dimensionless quantity that characterizes the radial ...
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1answer
190 views
How many solar system objects that can really qualify as a KBO are likely to enter Pluto's Hill sphere each day?
A comment below Which celestial body is able to come closest to Pluto? says that
Technically, many, many small Kuiper belt objects enter Pluto's Hill Sphere (or sphere of influence SOI) every day.
...
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Ptolemy’s understanding of the planet’s whereabouts
I imagine that Ptolemy’s epicycles were performed as real circles - around equants - in two dimensions, e.g that he was able not only to give the angles to planets and the Sun as seen from the Earth, ...
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Is it at all possible for the sun to revolve around as many barycenters as we have planets in our solar system?
Though it is understandable that the sun and the earth may be revolving around a barycenter, but, if so, not only the sun and Jupiter should also be revolving around some barycenter, the same should ...
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Where is the Solar system's barycenter located?
Where is the Solar system's barycenter located?
The solar system as a whole, Where is the center of the mass for the combined mass of the Sun, inner planets, and gas giants, is it inside the Sun? Is ...
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Why do the solar system planets go rock-gas-ice instead of rock-ice-gas when moving away from the sun?
The sun and the solar wind seem to do a good job of fractionating lighter materials to the outer solar system and leaving heavier materials in the inner solar system. So we end up with rocky/metallic ...
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1answer
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Is Jupiter really shepherding the main belt, and Neptune the Kuiper belt?
By "dominating another object's orbit" my understanding is that the most massive body's gravity has so much influence that, when they come close, it makes the other body/bodies' orbits shift ...
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Launch windows for Venus transit; how to convert heliocentric longitudes to date?
Being a bit familiar with celestial mechanics, I know that the Hohmann transfer orbit is the quickest way to transfer between two circular orbits of different radii around a central body in the same ...
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1answer
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How precisely we know the Gaia spacecraft baseline? [Question related to Planet 9 and the cosmic distance ladder]
The European Space Agency mission Gaia is performing an outstanding job by measuring the parallaxes of almost 2 billion stars, many of which are thousands of light years away from the Sun. For this ...
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21 views
Rotational inertia, angular momentum of the Solar system
Is there Rotational inertia of the Solar system as one entity "disk"? Is this even possible?
The angular momentum of a multi-point system in the Solar system - Since the different planets ...
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Rotational inertia of the Solar system
Is there Rotational inertia of the Solar system as one entity "disk"?
Is this even possible?
Edit:
The angular momentum of a multi-point system in the Solar system - Since the different ...
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1answer
130 views
What is the YORP effect exactly? Is it just the non-central component of the Yarkovsky effect?
This answer to Where have all the Vulcanoids gone? links to the aptly-titled The YORP Effect Can Efficiently Destroy 100 Kilometer Planetesimals At The Inner Edge Of The Solar System which says in ...
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Where have all the Vulcanoids gone?
This answer to Does anything orbit the Sun faster than Mercury? explains that while Vulcanoid asteroids may have been plentiful in the past, large ones have currently been ruled out though smaller ...
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Moons with curlicue paths around our Sun?
I naively believed that since our Moon orbits Earth, and since Earth orbits the Sun, the path our Moon might take around the Sun would be this type of epitrochoid curve:
I was surprised and delighted ...
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156 views
The creation of comets
How are comet and meteors made, and what causes them to travel through space so fast? I have tried researching, but I decided this was the faster way.
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Are the Jupiter-Saturn conjunctions and winter solstice related?
There is conjunction of Jupiter and Saturn on Dec 21. And there is another celestial event on that day the winter solstice.
So I'm just wondering that are these two events are related or not?
