another kind of solar system?

Question

my cousin who is in, high school, has a report due which involves creating their own kind of solar system. taking the task to heart, she then came up with:

2 suns (blue and red), 13 planets with her "home world" being the 5th one, the 4th and 6th planets crossing the 5th planet's orbit from time to time, the 5th planet has a ring around it with 4 different moons, the 5th planet has the usual 4 seasons, day and night, and an ice cap only on its northern hemisphere

now she wants me to come up with the number of days it takes for the planet to make a year, how often the 4th and 6th planets cross the 5th's orbit and how far the 2 suns are from the planets and each other.

needless to say, this is out of my league, so help! please? ;o)

Answer 1

I doubt such a system could actually exist for very long. Having planets crossing each others' orbits without a resonance (very unlikely with anything massive) is just asking for disaster (gravitational interactions will cause the planets to scatter each other into different orbits).

Two suns also causes problems though it is possible. Either they have to be close in with the planets orbiting the centre of mass of the two or far enough apart that they don't each perturb the habitable zone of the other.

Having a blue and red sun also seems unlikely to me since blue stars don't last very long (not long enough for intelligent life to evolve) and red stars are either really dim (though very long lived) with narrow habitable zones, tidal locking of any planets orbiting (which means that one side would be always day and the other always night) and a lot of flare activity (good at sterilising any life) or they are gigantic stars at the end of their life which don't have long left before they completely die (and they'll have sterilised any planets still left when they become giants).

If I were redesigning the system I'd swap one of the stars for a nice Yellow star (say G type (sol is G2) although late F and early K would do, in fact with the fifth planet being habitable I'd probably go for a brighter F type star, an F7 should do) and put a red dwarf (M type) orbiting the primary at significant distance (say about 7 or 8 AU) so that it won't screw up the orbit of any planets. I'd also stop having planets cross each others orbits though having a dwarf planet in a resonance with a larger one is fine (just like Pluto is in 3:2 resonance with Neptune).

Calculating the year length is just Newtonian mechanics provided you know the mass of the star and the semi-major axis of the planet's orbit (I wouldn't be making anything habitable have a very eccentric orbit, though you could if you wanted the seasons to be the same in both hemispheres).

Answer 2

Ok, if your cousin is planning on having one of the planets have life on it, her model is impossilbe since blue stars have a lifetime of millions of years, not billions of years. Life cannot exist with blue stars. If the star were red, orange, or yellow, that would be a different story. As for the fifth planet having only the northern pole having an ice cap, there would be no life on the planet unless the creatures can withstand temperatures of at least 900 degrees. So, basically, her solar system is impossible as far as our physics laws are concerned. A planet with seasons must have polar ice caps at both poles.


13 planets with her "home world" being the 5th one, the 4th and 6th planets crossing the 5th planet's orbit from time to time, the 5th planet has a ring around it with 4 different moons, the 5th planet has the usual 4 seasons, day and night, and an ice cap only on its northern hemisphere

now she wants me to come up with the number of days it takes for the planet to make a year, how often the 4th and 6th planets cross the 5th's orbit and how far the 2 suns are from the planets and each other.

needless to say, this is out of my league, so help! please? ;o)

Answer 3

As far as the periods that the planets intersect orbits wouldn't matter. The 4th planet should have a faster orbit than the 5th, and the 6th planet should have a slower orbit. And speaking of "days", they must have a reference.

A life-sustaining planet must be located within a distance from its sun (or suns) called a habitable zone. So all would be dependent upon the two sun's combined temperatures.
But blue stars are "O" type stars and carry temperatures of 20,000+ Kelvin, so it would have to lye at an extreme distance from the blue sun with a shielded atmosphere, or likewise get ready to burn like never before!!!

Answer 4

In reallity this kind of solar system cannot exist because the 2 Suns gravity will pull each other and that would be the end of everything. Same goes to the planets - no 2 planets belonging to 2 solar systems could cross orbits though in a single solar system it happens as we know - Neptune and Pluto. One day it will collide

Answer 5

Haha I'm curious to see what other people are gonna do. Okay so for the names I'm just writing random stufff :P My zodiac is based on times, not days, so the time frames will be parts of a day instead of months. It might not make sense cause not all time frames will be covered, that'd be too many :O Name:Smashoes Its Element: Fire Traits: sexy, godly, intimidating Ruled by: Ophicuhus (pretend it's a planet) Animal/Thing: Hammer Time Frame: 3 am-4 am Name:Glace Its Element: Ice Traits: immature, b*tches at people for no reason, mean Ruled by: An undiscovered planet Animal/Thing: Snake Time Frame: 12:30-12:45 am I know this kinda makes me sound like a b*tch for making this one, but whatever. Name: Ennudo Its Element: Air Traits: is bored with life, has split personalities, prone to impersonating people Ruled by: Uranus Animal/Thing: Donkey Time Frame: 5 am-6 am Name: Dickon Its Element: A mixture of darkness and light (if that even makes sense :P) Traits: likes being invisible and switching genders, likes creeping into people's houses, sexual stuff Ruled by: Mars Animal/Thing: Eyes Time Frame: 1 am-2 am Let's see if you can see who falls under each sign cause they were all "inspired" by people. I might add more later :P Wait there were other answers? They got deleted? :O