interesting facts about our solar system

[verbosity]

Feel free to add extra information and facts.........

earth has got 6 moons

well not quite, we only have one natural satellite, but we have 5 other "quasi-satellites" 3753_Cruithne , 54509 YORP, (85770) 1998 UP1, 2002 AA29, and 2009BD

Our Solar system is actually a Binary star

This is actually quite a contentious issue. The main evidence for the nemesis theory is the 'regular' increase of comets every 26 million years or so.

Nemesis is a hypothetical red dwarf or brown dwarf star, orbiting the Sun at a distance of about 50,000 to 100,000 AU, somewhat beyond the Oort cloud. This star was originally postulated to exist as part of a hypothesis to explain a perceived cycle of mass extinctions in the geological record.

there are thirteen planets
yeah ok I'm including so-called dwarf planets ( an issue still under debate). There are probably more, and I know of at least 3 additional submissions for Dwarf planets in the Trans-Neptunian region.
Sedna and CR105 are possibly also planets, though their shape has yet to be determined ( dwarf planets are big enough to have shaped themselves into spheres, aka have achieved hydrostatic equilibrium).



there are more than 200,000 planets in our solar system!!!!!
Again not quite :p , there are however over 200,000 minor planets in our solar system.

A minor planet is an astronomical object in direct orbit around the Sun that is neither a planet nor a comet.

here be centaurs !
half asteroid, half comet! Centaurs. While not the first object to be considered a centaur, 2060 Chiron is the first discovered that actually was ( confused? 944 Hidalgo was thought to be a centaur, but its not, it's just centaur-like )


lastly, though not quite a 'fact' there is a very cool free program called Celestia, its very cool!

[Edited on 8-3-2009 by verbosity]

[Maarschalk]

Very cool Verbosity, Thanks for sharing!

[Karmasaur]

outstanding. I didnt know about the extra moons of earth! Gotta dig into that one.

You didnt mention Trojans. Debris that has a synchronous orbit with a planet, around the sun.
Mars has them, Jupiter, and Neptune.

http://en.wikipedia.org/wiki/Trojan_(astronomy)

[GAlex]

i don't want to be too "restrictive", but precision is averyting, so...

[...Our Solar system is actually a Binary star ...]
uhmmmm... i'd like to hear an astrophysician state that...
you could say that someone has proposed that solution for that problem, but it has not been confirmed.

[...so-called dwarf planets (an issue still under debate)...]
it's no more under debate.
August 2006:
The IAU ... resolves that planets and other bodies, except satellites, in our Solar System be defined into three distinct categories in the following way:

(1) A planet is a celestial body that (a) is in orbit around the Sun, (b) has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a hydrostatic equilibrium (nearly round) shape, and (c) has cleared the neighbourhood around its orbit.
(2) A “dwarf planet� is a celestial body that (a) is in orbit around the Sun, (b) has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a hydrostatic equilibrium (nearly round) shape, (c) has not cleared the neighbourhood around its orbit, and (d) is not a satellite.
(3) All other objects, except satellites, orbiting the Sun shall be referred to collectively as “Small Solar System Bodies.�

Footnotes:
1 The eight planets are: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune.
2 An IAU process will be established to assign borderline objects either dwarf planet or other status.
3 These currently include most of the Solar System asteroids, most Trans-Neptunian Objects (TNOs), comets, and other small bodies.

On June 11, 2008, the IAU Executive Committee announced a name, plutoid, and a definition: all trans-Neptunian dwarf planets are plutoids.

[...there are more than 200,000 planets in our solar system!!!!!
Again not quite :p , there are however over 200,000 minor planets in our solar system. ...]
according to the above definitions, there are 8 planets, an increasingly number of dwarf-planets, and many "small solar system bodies" you can't name it as "planets", nor "minor planets". still, "minor planets" is a common term (cfr. "Minor Planet Center")

there are also three distincted family of NEA: Atens, Apollos, Amors, which orbits are in proximity of earth's.

Celestia rocks, but also give a try at "Stellarium", and, if you have a linux installation, definitely try XEphem, simple, rough, but extremely powerfull. (all these are OpenSource projects).

[verbosity]

Yeah ok my titles were a bit sensationalist, but if its good enough for new scientist

Originally posted by GAlex
[...Our Solar system is actually a Binary star ...]
uhmmmm... i'd like to hear an astrophysician state that...
you could say that someone has proposed that solution for that problem, but it has not been confirmed.

http://muller.lbl.gov/pages/lbl-nem.htm

I did point out that thats its hypothetical, and evidence for its existence (or not ) should appear within the next year or two

[...so-called dwarf planets (an issue still under debate)...]
it's no more under debate.
August 2006:
The IAU ... resolves that planets and other bodies, except satellites, in our Solar System be defined into three distinct categories in the following way:

(1) A planet is a celestial body that (a) is in orbit around the Sun, (b) has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a hydrostatic equilibrium (nearly round) shape, and (c) has cleared the neighbourhood around its orbit.
(2) A “dwarf planet� is a celestial body that (a) is in orbit around the Sun, (b) has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a hydrostatic equilibrium (nearly round) shape, (c) has not cleared the neighbourhood around its orbit, and (d) is not a satellite.
(3) All other objects, except satellites, orbiting the Sun shall be referred to collectively as “Small Solar System Bodies.�

Actually there is quite a lot of debate in this issue, mostly based on the " has cleared the neighbourhood around its orbit." part, Including the fact that depending on how you calculate this, And while the IAU has decided it is still a common area for debate.

according to the above definitions, there are 8 planets, an increasingly number of dwarf-planets, and many "small solar system bodies" you can't name it as "planets", nor "minor planets". still, "minor planets" is a common term (cfr. "Minor Planet Center")

Before 2006, the International Astronomical Union had officially used the term minor planet. During its 2006 meeting, it reclassified minor planets and comets into dwarf planets and small solar system bodies.

The IAU states: "the term 'minor planet' may still be used, but generally the term 'small solar system body' will be preferred." However, for purposes of numbering and naming, the traditional distinction between minor planet and comet is still followed."
http://www.iau.org/public_press/news/re ... s_answers/

so it is still fair to say that there are over 200,000 Minor planets.

Thanks I'll check out Stellarium

[Edited on 8-3-2009 by verbosity]

[Karmasaur]

Since some smart people are talking astronomy, I have a question. I mentioned the trojans earlier. I dont see how they can follow the same orbit, same speed, distance to the sun, as their planetary counterpart. Jupiter has a HUGE mass, and is affected by inertia, centrifugal force, gravity, and so on. Jupiters trojans have nowhere near the mass, yet they keep exact step with Jupiter. Why dont they fly away?

[Maarschalk]

Originally posted by Karmasaur
Since some smart people are talking astronomy, I have a question. I mentioned the trojans earlier. I dont see how they can follow the same orbit, same speed, distance to the sun, as their planetary counterpart. Jupiter has a HUGE mass, and is affected by inertia, centrifugal force, gravity, and so on. Jupiters trojans have nowhere near the mass, yet they keep exact step with Jupiter. Why dont they fly away?

http://en.wikipedia.org/wiki/Trojan_(astronomy)
if you look at the picture you see that the trojans of jupiter are in the same ring limit as jupiter. Compare it to electrons orbitting protons in the same electron ring. looks like the trojans also clump together as marked with green. So maybe the total mass combined of all the trojans in the ring of jupiter keeps the balance so that they do not fly away. Just like the astroids of different sizes in the astroid belt or the different sizes of objects in saturns rings. Once trapped at a certain distance in one of the gravity or electro magnetic rings objects move in the same fashion that are in the same ring! Remember it is not only gravitational forces that are at work here!

[Wasp89]

Originally posted by Maarschalk

Originally posted by Karmasaur
Since some smart people are talking astronomy, I have a question. I mentioned the trojans earlier. I dont see how they can follow the same orbit, same speed, distance to the sun, as their planetary counterpart. Jupiter has a HUGE mass, and is affected by inertia, centrifugal force, gravity, and so on. Jupiters trojans have nowhere near the mass, yet they keep exact step with Jupiter. Why dont they fly away?

http://en.wikipedia.org/wiki/Trojan_(astronomy)
if you look at the picture you see that the trojans of jupiter are in the same ring limit as jupiter. Compare it to electrons orbitting protons in the same electron ring. looks like the trojans also clump together as marked with green. So maybe the total mass combined of all the trojans in the ring of jupiter keeps the balance so that they do not fly away. Just like the astroids of different sizes in the astroid belt or the different sizes of objects in saturns rings. Once trapped at a certain distance in one of the gravity or electro magnetic rings objects move in the same fashion that are in the same ring! Remember it is not only gravitational forces that are at work here!

Silly silly, what did they teach you in grade school? Do objects with different masses fall at different speeds? Is the acceleration on a feather dropped near the surface of the earth in a vacuum any different than that of a two ton boulder?

An orbit is essentially the perpetual falling of an object towards a gravity body. Size matters not! Speed is what determines whether an object will maintain a stable orbit.

[Edited on 8-4-2009 by Wasp89]

[Wasp89]

Oops. It would appear I just quoted myself instead of editing my last post, so I edited this post and deleted in this post my quotation of my last post.


[Edited on 8-4-2009 by Wasp89]

[Maarschalk]

Originally posted by Wasp89

Originally posted by Maarschalk

Originally posted by Karmasaur
Since some smart people are talking astronomy, I have a question. I mentioned the trojans earlier. I dont see how they can follow the same orbit, same speed, distance to the sun, as their planetary counterpart. Jupiter has a HUGE mass, and is affected by inertia, centrifugal force, gravity, and so on. Jupiters trojans have nowhere near the mass, yet they keep exact step with Jupiter. Why dont they fly away?

http://en.wikipedia.org/wiki/Trojan_(astronomy)
if you look at the picture you see that the trojans of jupiter are in the same ring limit as jupiter. Compare it to electrons orbitting protons in the same electron ring. looks like the trojans also clump together as marked with green. So maybe the total mass combined of all the trojans in the ring of jupiter keeps the balance so that they do not fly away. Just like the astroids of different sizes in the astroid belt or the different sizes of objects in saturns rings. Once trapped at a certain distance in one of the gravity or electro magnetic rings objects move in the same fashion that are in the same ring! Remember it is not only gravitational forces that are at work here!

Silly silly, what did they teach you in grade school? Do objects with different masses fall at different speeds? Is the acceleration on a feather dropped near the surface of the earth in a vacuum any different than that of a two ton boulder?

An orbit is essentially the perpetual falling of an object towards a gravity body. Size matters not! Speed is what determines whether an object will maintain a stable orbit.

[Edited on 8-4-2009 by Wasp89]

No of course not but the 2 ton boulder will kill ya first if not the Vacuum will, while the feather gets stuck by static electricity to the vacuums glass or plastic wall! I tell ya there are other forces at work! LOL:P:P:P:P:P

[verbosity]

Originally posted by Wasp89
An orbit is essentially the perpetual falling of an object towards a gravity body. Size matters not! Speed is what determines whether an object will maintain a stable orbit.
[Edited on 8-4-2009 by Wasp89]

Actually Size can matter, esp when considering Lagrange points.

this should help explain trojans, as well as the 'horseshoe' orbits of some bodies, but the mass must be negligible mass compared to the masses of the 2 other bodies.

[Karmasaur]

If earth suddenly weighed 1/1000 of what it weighs now, it would swing out of course. I am sure of it. Our moon too, not having its dancing partner any more, would fly off in some random direction. It would change how the tug of gravity between earth and the sun works, and the earth and the moon.

I still dont see how a little chunk of debris, can act like a gaseous super planet. Obviously the DO, I just dont see how.

[Edited on 8-4-2009 by Karmasaur]

[verbosity]

Originally posted by Karmasaur
If earth suddenly weighed 1/1000 of what it weighs now, it would swing out of course.[

I still dont see how a little chunk of debris, can act like a gaseous super planet. Obviously the DO, I just dont see how.
[Edited on 8-4-2009 by Karmasaur]

Think about it this way, there is an escape velocity for the planet earth (11.2 km/s), its does not matter the mass of the object, it needs to maintain that speed to escape, orbits aren't that far different. as a rule you need to speed to be roughly 70% of the escape velocity at that point

Mercurys speed: 47.87 km/s Suns escape velocity at Mercury: 67.7 km/s
Earths Speed: 29.78 km/s Suns escape velocity at Earth: 42.1 km/s
Jupiters speed: 13.07 km/s Suns escape velocity at Jupiter: 18.5 km/s
Neptunes speed: 5.43 km/s Suns escape velocity at Neptune: 7.7 km/s

Please note this is an over-simplification,


If earth lost 99% of its mass, but still kept its momentum if would fly out of place ( since its speed would change), but if the 1% left kept the same speed and direction it would stay in the same orbit ( not counting the effect of the moon).


The suns mass is equivalent to 332,900 Earths , if Earth lost 99.9% of its mass the gravitational relationship between itself and the sun would not change a great deal ( small enough to be ignored ), in fact even Jupiter (317.8 Earths) losing 99.9% of its mass would not effect their relationship enough to force what was left to leave its orbit.

[Edited on 8-4-2009 by verbosity]

[GAlex]

it's very, very simple, the Lagrangian points are the stationary solutions of the circular restricted three-body problem.

given the masses and distances of the first 2 bodies and the initial position and the velocity vector of a third small body (small compared to the first 2) you can calculate it's orbit evolution.
in this matter orbit resonance (when orbital periods of two bodies stays in a simple integer ratio as 1:2, 2:3, etc) is also implied.

so, at the beginning, the great amount of small objects which intersects (in this case) jupiter's orbit, where pushed down the inner solar system, or to the outer (edgeworth-kuyper belt and beyond), or confined in the lagrangian points L3, L4 and L5. we have trojans on L5, greeks on L4.
and we have Hilda family of small bodies in L3, L4, L5: since their orbital resonance 2:3, every Hilda family's object touches all the 3 Lagrangian points every 3 orbits.

you can try to figure it out yourself, the math involved is very basic. you can find propositions and demonstrations in any basic physic schoolbook, or you can start from wiki page on euler's three-body problem and take a look at the bibliography.

a tip: don't be scared by formulas, the bigger these are, the simpler to understand.

[Barreta]

We live on a doomed planet. Get used to the idea.

[IckleChesh]

The Sun contains 99.86% of the solar system's known mass. Jupiter, Saturn, Uranus and Neptune account for 99% of the remaining 0.14% of the mass, with Jupiter and Saturn together comprising more than 90% of that.

[Maarschalk]

Originally posted by Barreta
We live on a doomed planet. Get used to the idea.

Not at least for another 500,000 years or more!;)

[warsign]

LOL.
Doomed Planet! Really it is.