Questions tagged [solar-system]

Questions regarding the Sun and objects orbiting it.

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99 views

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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Precision in the space navigation [migrated]

I am curious about the precision NASA and other agencies have in the space navigation. Are they always accurate to the meter in position they aim for; in mission like the recent rover landing on the ...
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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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172 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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116 views

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
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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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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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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
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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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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. However, I have not seen anything about its potential whereabouts. Assume this gas giant (let's call it G5) was ...
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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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91 views

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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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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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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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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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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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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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?
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Do the axes of rotation of most stars in the Milky Way align reasonably closely with the axis of galactic rotation?

The axis of rotation of the Solar System makes a large angle of about 60 degrees relative to the axis of rotation of the Milky Way. That seems unusual - for example, most of the bodies within the ...
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1answer
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How does the Sun's gravity have so much force and pull on the solar system? How does it scale?

Watched this video: https://fb.watch/1U0vCFBr0L/ Ok, so the distances are huge. And the sizes are much different. But I wonder how then the sun keeps the planets etc. orbiting it. If we swap out all ...
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What are the correct positions or alignment of planets in relation to each other and the Sun, is it vertical center, baseline or completely random

From a lot a illustrations and videos, the planets seem to align in vertical center to each other like this: Is this really true? I like to imagine that the planets are actually in weird alignment to ...
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What makes protoplanetary disks start rotating? (Initial energy needed to rotate)

Planets form from a protoplanetary disk that has been rotating around its star. The initial energy that makes them rotate really matters to me. Why did the protoplanetary disk start rotating around ...
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Did Mercury clear its neighborhood?

For a body to qualify as a planet according to the IAU definition it must have "cleared its neighborhood". What evidence is there Mercury indeed cleared its neighborhood? Perhaps it migrated ...
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Positions of planets before Christ?

All the solar system simulations I've come across showing the positions of planets only show the positions in a certain time period, at beginning of the first millenium the earliest. There was just ...
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When I see Mars, I see only red light

I have a 700 mm focal and 76 mm aperture telescope. I bought it a few days ago. I tried to spot Mars for 3 days but I only see red light. I use an 20 mm eyepiece for finding it and 4 mm eyepiece for ...
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Can a planet in our system eclipse the sun as seen from another one?

When the Sun, Earth and Moon get properly aligned, we get eclipses, where the Sun is partially or totally hidden by the Moon when seen from Earth. Is it possible for one planet of the solar system to ...
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How has the average distance between asteroids in the asteroid belt changed over time?

Just about every webpage related to asteroids states that, on average, asteroids are about 600,000 miles apart from one another. Have planetary scientists hazarded a guess at how close they might ...
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Long-periodic sungrazers

I'm searching for long- and non-periodic sungrazing comets, like the Kirch comet of 1680 and the (meanwhile destroyed) Comet ISON. If you know a(ny) long-/non-periodic sungrazing comet(s), let me know ...
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Orbital Mechanics: where can I find initial conditions for orientations and angular rates of planets in our solar system?

I am looking to write the equations of motion (EOMs) for a 6DOF analysis of our solar system. I want to integrate the equations forward in time, and need a complete set of initial conditions to do so....
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217 views

How do we weigh a planet?

How do we weigh a planet? My friend asked me how do scientists weigh a planet. He is not from science background so I need to make him understand with simple analogy. How can I explain to him?
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Could rocks from Earth have reached the Kuiper belt, or Neptune at least? If so, how?

This answer (currently edit 3) to How certain are we that we have not sent life to other planets/moons? begins: First of all, rocks from Earth are probably just about everywhere in the Solar System. ...

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