The Sun plus the collection of bodies in orbit around the Sun such as planets, dwarf planets, moons, asteroids, comets, etc.
Questions tagged [solar-system]
717 questions
78
votes
6 answers
How can we see planets thousands of light years away but don't know if there are more planets in the solar system?
That is basically my question, it arose when I saw an article (here is the scientific paper, which should be free to read) saying two Caltech scientists might have found the 9th planet of the solar system.
Suriya
- 1,768
65
votes
15 answers
Why do we say that the Earth moves around the Sun?
In history we are taught that the Catholic Church was wrong, because the Sun does not move around the Earth, instead the Earth moves around the Sun.
But then in physics we learn that movement is relative, and it depends on the reference point that…
HappyDeveloper
- 1,397
63
votes
3 answers
Do solar systems typically spin in the same direction as their galaxy?
Is the net angular momentum vector of our solar system pointing in roughly the same direction as the Milky Way galaxy's net angular momentum vector? If yes or no, is that common for most stars in the galaxy?
Alex
- 6,105
62
votes
4 answers
How far ahead can we predict solar and lunar eclipses?
The solar system is non-integrable and has chaos.
The sun-earth-moon three-body system might be chaotic.
So, how far into the future can we predict solar eclipses and/or lunar eclipses?
How about 1 million years?
Jiang-min Zhang
- 4,262
56
votes
6 answers
What did general relativity clarify about Mercury?
I frequently hear that Kepler, using his equations of orbital motion, could predict the orbits of all the planets to a high degree of accuracy -- except Mercury. I've heard that mercury's motion couldn't be properly predicted until general…
Carson Myers
- 5,111
49
votes
1 answer
Why are our planets in the solar system all on the same disc/plane/layer?
I always see pictures of the solar system where our sun is in the middle and the planets surround the sun. All these planets move on orbits on the same layer. Why?
Stephan Schielke
- 975
43
votes
2 answers
Is our solar system really that odd?
I have been learning about the solar system from popular science shows. In these shows they suggest that, after having seeing around 2500 other solar systems, astronomers have concluded that our solar system is not the normal one. They see sun…
Ben Sprott
- 1,430
42
votes
4 answers
How far out from the Sun is visible light still sufficient to read a book?
Recent pictures from the New Horizons spacecraft, shown below, seem to indicate that, at Pluto's distance, we are entering a twilight zone, with a distinct lack of colors, although that could be due to the planet terrain itself or the camera used to…
user81619
40
votes
8 answers
"Falling upward" - how far you have to be from Earth to start falling to the Moon?
Talking about gravity with my 9 y/o she asked when do we start "falling upward" to the Moon. What is the distance at which the Moon's gravitational attraction is higher than that of the Earth and thus makes you accelerate towards it, and how to get…
rafb3
- 525
39
votes
3 answers
Can the solar system really fit in a thimble?
Almost every time somebody talks about atoms, at some point they mention something like this:
If we remove the spaces between the atoms and atomic components, we can fit the solar system in a thimble.
Or
If we remove the spaces between the…
Adi
- 1,628
38
votes
4 answers
Why is Earth's climate so stable?
Earth wasn't always the only water-world in the solar system. Mars also appear to have started out wet
but, as conditions changed, Mars lost its oceans.
So, how has Earth managed to avoid a similar fate?
Doesn't the Giant impact hypothesis…
Achmed
- 1,139
36
votes
4 answers
Why doesn't the solar wind disrupt the planets?
The sun creates this heliosphere by sending a constant flow of particles and a magnetic field out into space at over 670,000 miles per hour, which is also known as solar wind. If the speed of the wind is that great, why doesn't it disrupt the…
Tammy Chong
- 543
35
votes
5 answers
How do you calculate the anomalous precession of Mercury?
One of the three classic tests of general relativity is the calculation of the precession of the perihelion of Mercury's orbit.
This precession rate had been precisely measured using data collected since the 1600's, and it was later found that…
David Z
- 77,804
35
votes
5 answers
Can the Schrodinger equation describe planetary motion?
I was asked on an exam whether the Schrodinger equation can be used to describe planetary motion and my answer was "No, because the solutions are wavefunctions which give probabilities but everything can be exactly measured for large objects."
Then…
WarreG
- 929
33
votes
3 answers
Is there a maximum distance from a planet that a moon can orbit?
Given a planet that orbits a star, and a moon that orbits that planet, is it possible to define a maximum orbital radius of that moon, beyond which the moon would no longer orbit the planet, but the star instead?
I initially (naively) thought this…
leeman
- 432