Questions regarding the earthly Sun and objects orbiting it.

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Retrograde motion and Kuiper Belt Objects

As seen from Earth, planets such as Mars and Jupiter exhibit retrograde motion when they are near opposition (from Earth). I am wondering how this effect extends to very distant objects, such as ...
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1answer
132 views

How bright was Scholz when is passed near the Sun 70,000 years ago?

I just read that a star called Scholz passed only 0.8 years-light away from us 70,000 years ago. It is a red dwarf. I donĀ“t know how bright it was in the night sky. Does someone know how bright it ...
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1answer
64 views

Is there a general term for epicycles, deferents, and eccentrics in Ptolemaic astronomy?

According to Ptolemy's (c. 150 CE) account of the motions of planets, planets moved in circular paths ("epicycles") around center points that in turn moved around the center of the earth along a path ...
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2answers
123 views

How much magnification is needed to see planets of solar system?

I have a 3inch Newtonian reflector telescope with 300 mm focal length. I can use highest magnification of 75x using a 4mm eyepiece. But in 75x I can't see details of Jupiter what was expected. Instead ...
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1answer
28 views

Precessing of the Earth

It's been known that the Earth's axial tilt varies from 22.5 to 24.5. Does this result in a wobbling while the value of the tilt varies about these two limits? If so, how does it affect the mechanics ...
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88 views

Why there are other planets in our solar system?

Why there are planets in our solar system other than Earth? Only Earth supports life. What is the significance of other planets? Earth receives sunlight from Sun; in a similar way, do we receive any ...
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2answers
49 views

Is it proper to refer to objects beyond Neptune as “Kuiper Belt Objects?”

It seems to me that nowadays the more proper term is "Trans-Neptunian Object". Is there any difference between Kuiper Belt Objects and Trans-Neptunian Objects? If not, is one term preferred over the ...
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2answers
87 views

Why are gas giants colored the way they are?

As I understand it, Jupiter, Saturn, Uranus, and Neptune are all made primarily from varying proportions of hydrogen and helium. Despite this, Jupiter is very red, Saturn is yellow, and Uranus and ...
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108 views

Is it possible to disprove geocentrism without telescopes?

The development of telescopes enabled the discovery of moons orbiting around Jupiter, and the existence of a full set of phases of Venus, as opposed to a limited set which would be predicted by ...
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2answers
70 views

Could there be another planet between Mercury and the Sun?

Could there be another planet between Mercury and the Sun? Kepler found a lot of planets orbiting its star even 20 times closer than Mercury. If there were such planets in our system - would it be ...
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2answers
79 views

In geocentric models, did the earth rotate?

Under geocentric models, did the earth rotate around its axis? I assume that if the earth rotated around its axis, then the sun would not have to orbit around the earth at a very fast rate, whereas ...
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2answers
115 views

What proportion of planetary systems have been found with 'Hot Jupiters'

According to the NASA website "The strange attraction of Hot Jupiters", one of the main types of exoplanets that have been detected are Hot Jupiters, which are These are behemoth worlds that ...
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5answers
565 views

Why can't I see Mars clearly?

I just bought my first telescope - a Celestron CDC 1100. It came with a 40mm lens so with a primary focal length of 2800mm the power should be 70x. My problem is that I've looked at Sirius and Mars ...
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2answers
60 views

Finding the temperature of Earth from temperature of Mars and its distance from Sun

I am to compute the temperature of planet--in fact I've already found out it's Earth--knowing only: the surface temperature of Mars (210 K) and its distance from Sun (1.524 AU) and of course ...
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1answer
100 views

Could the planets in the Solar System have been captured?

Ignoring any current beliefs, is it possible that the planets could have been captured by the Sun's gravitational force after drifting through space while retaining their axis of spin and speed? ...
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2answers
82 views

Meteorites bring water

The latest information suggests that Earth's water came from Meteorites . The Moon was also bombarded by Meteorites and yet it has no water. Is this because it lacks an atmosphere and its water was ...
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1answer
149 views

How did scientists determine an estimate of the number of planets greater than Sedna's size to exist in the Inner Oort Cloud?

In the article, New Dwarf Planet Found at Solar System's Edge, Hints at Possible Faraway 'Planet X' (Wall, 2014) where they report on research and observations performed by astronomers that discovered ...
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2answers
3k views

Can our Sun become a black hole

Does every star become a black hole? Is there any probability that our sun can become a black hole? If yes then is it on its way to become a black hole? what is the current state of sun as per the ...
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2answers
81 views

Full Moon Position of Sun

I am trying to figure out the position of sun with respect to moon on a full moon day. Here's an image from certain wiki which I do not find convincing. 1 If the sun rays point as shown in the image ...
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2answers
123 views

How did Bradley arrive at the +/- correct speed of light when he calculated it?

After Bradley discovered stellar aberration and the corresponding constant of aberration he was able to calculate the speed of light, since he knew the speed of the Earth around the Sun. As far as I ...
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3answers
42 views

Why dont we have a browsable spacetime augmented virtual solar system?

Wouldnt it be nice to be able to render any viewpoint from all the data transformed into a point cloud, an augmented virtual reality of moving objects in our solar system. I would just like to be ...
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3answers
90 views

Stable polar solar orbit with the Earth continuously observable

Is there a stable polar solar orbit such that the Earth is always in view and not eclipsed by the Sun?
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2answers
119 views

Hamiltonian of general three body problem

i try to extend my analysis from planar restricted three body problem to the general one. Is there anyone that can help me to find out the Hamiltonian for this prolem in cartesian coordinates? I ...
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1answer
86 views

Look up current positions and velocities of solar system objects

I am working on an orbital dynamics code and, for fun, I would like to model the Sun-Earth-Moon system with my code. I can look up the masses of each object just fine, as well as average distances ...
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2answers
83 views

What is the orbit of Earth around the Sun?

According to wikipedia and other sources, a planet and a star always move in a circular orbit around the common center of mass of the both bodies, in case of Earth and sun, this center of mass lies ...
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3answers
743 views

Where does the solar system end?

This is a question I've heard many times in the past, and a quick search of the site says it hasn't been asked here, so I figured I might as well ask (and answer) it. I know that it is rare for ...
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1answer
67 views

Solar System' formation, considering its and universe's age

It's been said that the sun has 4.6 billion years, and the complete solar system to have similar age. The star-class of the sun seems to be quite common. Stars of its class can have 8 or 9 billion ...
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83 views

Energetics of Titans Tholin haze

So, I've googled and wiki'd on this, but no clue, so I turn my question to the community: Given Titan's nice orange haze that is supposedly composed of Tholins and strangely coincides with its ...
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1answer
51 views

How to convert a gravitational force to speed and direction

I am doing some calculations, and I wanted to know that after using the gravity equation, $$F = G \frac{m_1m_2}{r^2}$$ if you can use $F$ and convert it into a speed, such as km/year, and also a ...
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3answers
185 views

Planets and Pluto? Neptune?

If one of the rules to be a planet is that it needs to clear ALL objects from their orbit, does this also make Neptune a non-planet? Since it has thus far failed to clear Pluto (and based on an answer ...
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2answers
62 views

Standard practices and models for generating the ephemerides of the solar system

I am familiar with the theory on generating the positions of the members of the solar system, but have been unable to find out the standard practices and methods of professional astronomers in ...
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2answers
110 views

The defintion of star/planetary/solar system

In many science fiction stories, we hear the term star system that mostly refers to a star and its planets. This is often used interchangeably with the term solar system. But after some research I ...
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93 views

How bright are the outer planets, when at close range?

Seven probes have passed by or orbited outer planets. I wonder how their photos differ from the naked eye view one would have if one were actually there. Saturn is 10 AU from the Sun, which means ...
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97 views

Composition of planets' core

It is often possible to find a list of the materials that compose the cores and the mantle of plantes (often they are iron and/or nickel). How can these materials be determined in our Solar system? ...
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4answers
2k views

Is Pluto still a dwarf planet?

Recent news seem to suggest that astronomers are arguing about whether Pluto should become a planet again. However, I cannot find an official source for this. Is this actually true?
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1answer
245 views

Do we get any benefit from being in a galaxy?

If our solar system were to somehow be created outside of a galaxy as a single star in the vast nothingness between galaxies, would life on Earth change any? Does being a member of a galaxy actually ...
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2answers
1k views

Do all stars have an oort cloud or is it a rare occurance?

Do all stars have an oort cloud like ours that will be filled with comets and other objects? If not, why are they not around every star?
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374 views

When will all eight planets in our solar system align?

Ignoring expansion of the universe, entropy, decaying orbits, and interference from any bodies colliding with or otherwise interfering with their orbits, will the eight planets known planets in our ...
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1answer
66 views

The furthest horizon in the Solar system

Where can I observe the furthest horizon in the Solar system ? And what the length of it ? The furthest horizon on Earth can be observed from mount Everest ~ 336 km, On Mars - from mount Olympus ~ 386 ...
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55 views

Venus started with retrograde rotation? [duplicate]

I have heard that when our solar system formed that all planets except Venus were revolving around the sun in the same direction because of the normal rotation of their axes. Venus was rotating and ...
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Advancement of perihelion, data

I was looking for accurate and up-to-date data regarding the advancement of the perihelion of the planets in the Solar System, the only ones I've found so far are at least 90 years old bout I really ...
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3answers
170 views

I know when the human history ends. Or not?

If you think that we born on 1920...2000 and knows that the sun will explode 4 to 5 billion years from now. you will say that the time is a strange thing. I can not say that i will die before i know ...
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103 views

Did the Late Heavy Bombardment Period Happen Because of a Stellar System Collision?

I was thinking about the impending collision between M31 and the milky way galaxy, and I've heard that since a galaxy is mostly space most of the contents of both galaxies would be just fine. Could a ...
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1answer
110 views

Why natural satellites (moons) of all Planets are Solid?

Why the natural satelittes (moons)of all planets including moons of Gas Giants are are Solid or Rocky and not gaseous like them?
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252 views

What's the likelihood of the existence of unknown elements in the Solar System?

What's the chance that there might be undiscovered chemical elements in the Solar System - either on planets or around the Sun or on asteroids of the Oort-cloud?
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358 views

Why do (most of) the planets rotate counterclockwise, i.e. the same way the Sun does?

Referring to the mechanisms explaining the solar system formation and to the initial rotation of the gaseous cloud that collapsed, I understand easily why the planets orbit the Sun the same way this ...
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1answer
1k views

Finding the solar noon based on longitude and latitude?

Please could someone advise the best method of finding the solar noon based upon location? http://pveducation.org/pvcdrom/properties-of-sunlight/suns-position The stuff on here has been helpful but ...
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156 views

Why do the rings around the Gas Giants get their 'ring' shape?

In our Solar System, all the gas giants have ring systems. However, why do these rings form rings and not a cloud of debris around the planet?
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113 views

Is the argument of perihelion random?

I am currently designing star and planet systems in the RPG framework GURPS. This game system has a very elaborate set of rules to set up a star system, complete with planets and the like. However, ...