Questions tagged [solar-system]

Questions regarding the Sun and objects orbiting it.

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2
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1answer
441 views

Understanding the theory of an expanding Universe

How did Edwin Hubble determine the Universe was expanding? Was he looking in a particular direction? And where does this Galaxy sit in the expansion.
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0answers
664 views

How to calculate the orbits of Neptune and Pluto based on the orbits of Uranus and Neptune respectively?

I get the below from Neptune and Pluto. In 1821, Alexis Bouvard published astronomical tables of the orbit of Neptune's neighbour Uranus.[22] Subsequent observations revealed substantial deviations ...
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1answer
114 views

If a star orbited another star, how would that affect parallax measurements of the other star from the vantage point of the first?

Example: If hypothetically, the vantage point would move 2AU along an orbit around the star being measured, would that make it seem as if the other star moved twice the distance over the back-drop?
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1answer
322 views

How to calculate planetary position over vast time spans

Ignoring the turbulent beginnings of our solar system I wonder if there is a meaningful way to calculate the relative position of the planets of our solar system 100 million years into the future ...
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2answers
1k views

“Official” time for other planets

I want to make clock that shows current time on different solar bodies. For that I need to know how to count time on those planets. Is there any official definition of times on other planets in our ...
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2answers
1k views

What is direction of Sun's axis of rotation relative to the Earth's orbital plane around the Sun?

The present northern direction to the nearest 0.5 degrees with degree zero being the start of January and measured counterclockwise (same as Earth's orbit relative to celestial north pole). If the ...
2
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1answer
750 views

Period of unique horoscopes?

What is the period of unique horoscopes? In other words how long does it take before any configuration of the classical planets repeats? The seven classical "wandering stars" are: Sun, Moon, Saturn, ...
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2answers
1k views

How can clouds form in Jupiter's atmosphere of Hydrogen and Helium?

Here is a graphic of cloud layers of Jupiter (source: Wikipedia): There are three distinct cloud layers of ammonia, ammonium hydrosulfide, and water. The temperature and pressure conditions seem to ...
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3answers
201 views

What can the average Astronomy Enthusiast do to learn more [closed]

Maybe this sounds like a silly question (and hopefully is legitimate), but I will elaborate a little more. I seem to love astronomy, every single thing about it, I find it brilliant, interesting, ...
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1answer
119 views

Are the “extinct species” of meteorites originally from the “Barbarian” asteroids?

I've asked earlierin this unanswered question about an "extinct species" of meteorite, now I've just read in Phys.org about Barbarian asteroids: Named after the first asteroid of this type ...
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2answers
150 views

Which kind of strategy should we take to discover Planet 9 and other KBOs?

What are the differences between the discoveries of Sedna, 2012vp 113, and the supposed Planet 9? All need deep infrared surveys at the ecliptic plane, but P9 needs a much deeper survey?
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1answer
1k views

'Very High Noon' - Sun directly overhead

Twice a year the sun is at a certain angle south (or north) of the equator between The Tropic of Cancer and The Tropic of Capricorn. At that time the sun will be exactly overhead for people at the ...
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1answer
716 views

Orbital elements of solar system using Pyephem

I'm using the astrometric python module Pyephem, and I would like to get the orbital (keplerian) elements for the solar system planets. The only values I found is the heliocentric latitude, ...
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1answer
3k views

How to calculate the current distance between two planets [duplicate]

I'd like to add a feature to one of my apps that calculates the current distance between the Earth and Mars (or any other planet, for that matter). My google searches have led me to statistics of ...
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2answers
232 views

Explaining the Drake Equation on a smaller scale

So me and my friend were planning a video to explain the Drake Equation (within a time limit of 5 minutes), and we needed some help. This video is aimed at explaining the concept to an age group ...
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1answer
509 views

Effects of the solar tide on planets

It’s well known that (lunar) tides on Earth result in a transfer of angular momentum from Earth proper to the Earth–Moon orbital motion. That’s why the Moon resides now in a high Earth orbit, and ...
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1answer
58 views

Observations of a perigee coincident with a full Moon

Hopefully this will be a quick and easy question, with a quick and easy answer, but why is it that we observe a perigee Moon coincident with a full Moon approximately every 13 months? Is this related ...
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2answers
528 views

Why are some universal entities round and others are flat?

I've been wondering for a while now why some objects in the universe (such as stars, planets, etc.) are round, while others are flat (galaxies, planetary rings and protoplanetary disks). I know these ...
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5answers
25k views

Is the Sun in our solar system moving or stationary?

When I was small, I read that Sun is fixed at the center of the solar system and that all the other planets rotate around it. But later I heard that even the Sun is not fixed; it moves. Is this true? ...
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2answers
703 views

How many judges sat on Galileo's trial over heliocentrism and who were they exactly?

I saw several chronologies of the trial online but most of them only mention the name of Urban 8 as involved in the actual court proceedings. How many judges were involved and who were they exactly? ...
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0answers
75 views

Are the Voyager spacecraft outside of our Solar System? [duplicate]

The wikipedia says that Voyager 1 cross the heliosphere, but is really outside the Solar System, or need to cross the Oort cloud?
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1answer
259 views

A question about the distribution of mass among the planets in the Solar System

Is it coïncidence that the mass of a planet has about its maximum in the middle planets (Jupiter), while the mass of the closest and furthest planets has a minimum (Mercury and Pluto)?
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2answers
766 views

Can stars be seen in the background when looking directly at our solar system?

Imagine viewing the solar system from the outside: Considering the sun is quite bright, would you still be able to see stars in the background, or does the sunlight disable us to do so? Consider ...
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2answers
875 views

Will Saturn's Moons be destroyed?

I heard that Saturn has 62 moons with confirmed orbits, 53 of which have names and only 13 of which have diameters larger than 50 kilometers. Some come within 1km of each other. How do these moons ...
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4answers
889 views

What are the exact causes that differences in sunrises are shorter around june and december but long in march and september?

The changes of the sunrise and sunset times not expire regularly in a straight line but according to a sinusoid. Around the solstice (summer solstice on June 21st and winter solstice on December 21), ...
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2answers
194 views

Does the retrograde movement affect the true angular distance between 2 planets?

I need to calculate the relative angular path between two planets in the geocentric view or in other words the number of degrees of a circle one planet travels away from another planet around the ...
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2answers
374 views

What is the word for space that is in the solar system, but outside the heliopause?

Wikipedia says the definition of interplanetary space is the region dominated by the interplanetary medium, which extends out to the heliopause where the influence of the galactic environment ...
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2answers
21k views

Why do the planets orbit in the same direction?

Theoretically, planets would have an approximately equal chance of going one way in their orbit or another but in reality, this is not the case (at least in our solar system). Why is this?
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2answers
816 views

If the planets only attract, then how can they stay in their orbit?

Gravity is related to mass, and gravity is an attracting force on every body. Then what happens when bodies only attract each other..without repulsion they may strike the sun. I think there must be a ...
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2answers
185 views

Is Earth slowing down in order to stay on its orbital track?

The Sun is losing some of its mass during explosions. The Gravitational force between Sun and Earth will change (probably decrease). If Earth maintains its speed, it will change its orbit. Hence, ...
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1answer
640 views

What is the Age Difference Between Earth & Jupiter?

What is the age difference between Jupiter & Earth? Which planet was formed first, or were they formed at the same time?
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1answer
156 views

Oscillation in tilt of the solar system

I know that the solar system is tilted 62.6° to the plane of the galaxy. I'm curious whether this angle changes over time, and what are the extents and time frame of any such oscillations if they ...
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4answers
2k views

How did the Earth come to be in orbit around the sun?

I'm not sure if this post should be in the physics subject forum, but this seems to fit here too. I have been reading a book about chemistry and how the universe came to be with the theory of stars ...
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3answers
776 views

Question related to Sun rise and Sun set times

I am not sure whether this question is right or not so bear with me. I understand 'Sun rise' and 'Sun set' is caused by the Earth's rotation. I read that 'Sun light' takes around 8 minutes to reach ...
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1answer
154 views

Is the material that could have formed a “Super-earth” divided among the four terrestrial planets

I know "super-earths" are quite common in other planetary systems, but there are none in the Solar System. Is it due to the material that could have created a single large super-earth being used to ...
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2answers
2k views

Could the 9th planet be virtual?

Astronomers recently claim that there is evidence for a 9th planet. As far as I understood it, this is mainly based on coinciding orbital parameters of a few Kuiper belt objects. Could the 9th planet ...
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0answers
48 views

The observation of changes barycenter of the solar system

Is it possible to observation changes in the barycenter of the solar system? There are graphics showing changes barycenter but they are made on the basis of computer simulation (E.g.: here and here). ...
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2answers
661 views

What is the effect of the axial precession on the orientation of the planet's orbits?

I am working on an online application to visualize the positions of the planets and to calculate their ephemerides (you find it here, but it is not complete yet). I do not have much knowledge in ...
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6answers
10k views

Why is the Sun's density less than the inner planets?

The density of the Sun is $1410~\frac{\text{kg}}{\text{m}^{3}}$ and Mercury's is $5430~\frac{\text{kg}}{\text{m}^{3}}$, but shouldn't the Sun be denser? Because when the Solar System was forming, ...
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2answers
382 views

Why did Mercury not appear to transit through the middle of the sun?

Why did Mercury not appear to transit through the middle of the sun (the equator)? I initially thought that this was because of the ecliptic, but, then I thought that actually we'd see it above the ...
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1answer
164 views

Why was the size of the solar system not defined by Mercury Transits?

The first measurements of the (absolute) size of the solar system was made using the Transit of Venus, an event that arguably will only happen twice in a lifetime. Transits of Mercury occur far more ...
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1answer
387 views

Could there be a brown dwarf in our solar system? [duplicate]

Is it possible that a brown dwarf object could be orbiting our star and undetected so far by wise surveys?
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3answers
776 views

Why do the gas giants in the Solar System have comparatively large orbits compared to the inner planets?

Ever since I observed the depictions of the Solar System, I was obsessed with the question of why the gas giants (outer planets) have very large orbits, compared to the planets that are closer to the ...
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1answer
146 views

Were there any images of a transitary event of Jupiter or Saturn as imaged by a deep probe mission

I'm quite certain that there isn't any actual images of a transitory event of Jupiter or Saturn across the solar disk from say e.g.,s the Voyager probe, Pioneer 10/11 or even recent New Horizons ...
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3answers
795 views

Retrograde motion of planets: reason and time?

As beginner, I would like to understand how planets exhibit retrograde motion. When does the retrograde motion start for a planet like Mars and how long (time limit) planets will appear to be in such ...
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1answer
226 views

Which class of objects in Solar System carries more mass?

Could you help me sorting this list in terms of total mass carried by these classes of objects? The star (Sun) - it's very big but only one. The planets (incl. dwarf planets). Certainly beaten by the ...
3
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1answer
371 views

Why are planets round? [duplicate]

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 ...
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3answers
108 views

Celestial impacts

Have we ever observed, or better yet, recorded, an impact from a comet/meteorite/fragment/etc on another celestial body? For example, in all its time orbiting Mars, has the MRO observed anything ...
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1answer
2k views

Why do comets appear to have a continuous supply of dust?

Comets orbiting the sun have a tail that points away from the Sun, due to the solar wind. (Strictly speaking, a comet can have both a type I tail - ion tail, and a type II tail - a dust tail. This ...
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2answers
131 views

What measures are currently in place to detect asteroids on possible collision courses with earth?

I know some measures must exist, but I have no idea what the programs are, what organizations are involved, or how effective they are.

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