<p>Well without your big brother jupiter looking out for poor little earth then life on earth wouldn't be possible (most likely, but definitely not intelligent life as it has taken us millions of years to evolve to this point, and meteor collisions would increase at an alarming rate). You receive a force on your body from all the planets in the solar system and everything in the universe for that matter, but they are neglible compared to the force you feel from earth. "But Jupiter is so much bigger than earth how could its gravity be negligible?"  Well the intensity of gravity is proportional to 1/distance^2 (one over distance squared) so the farther you are away from something the less gravitational effect it has on you, and earth is big enough that it is most likely the only gravitational effect your body will ever truly be aware of. However you can see the tidal effects caused by the moon. High tide low tide are created by the moon's gravity. I once heard a man say astrology (the arch nemesis of the astronomer) is based in the tidal affects on the heavy metals in one's body caused by the positioning of the planets at one's birth, which I had to admit made for a pretty convincing argument though I still don't read my horoscope. </p>

CC BY-SA 3.0
2015-02-09T19:29:00.390Z
It's likely that Jupiter's influence has protected Earth from collisions (or not; I don't know what the latest scientific consensus on that is). But your answer implies that that's the *reason* that Jupiter exists. If that's what you mean to say, then I would ask for something to substantiate that claim. Are you assuming some intelligent design behind the structure of the Solar System? If that's not what you mean to say, then I suggest that this doesn't answer the question in its current form.
Keith Thompson
CC BY-SA 3.0
2015-02-10T00:01:58.427Z
You should explain *why* Jupiter was so important. [This](https://en.wikipedia.org/wiki/Jupiter#Interaction_with_the_Solar_System) talks about it briefly.
HDE 226868
CC BY-SA 3.0
2015-02-10T08:15:36.473Z
Noon intelligent design the reason Jupiter exists is because that's how the cloud of matter accreted in the early solar system. Is this question philosophical?
jpstearns
CC BY-SA 3.0
2015-02-09T11:36:56.873Z
2015-02-09T11:36:56.873Z
jpstearns
<p>Did you mean to ask</p>

<p><strong>Would life on Earth be possible if Earth was the only planet in the Solar system?</strong></p>

<p>The answer is <strong>perhaps</strong> <em>, we can only speculate and know too little about the evolution of the planetary system to give any firm answer.</em></p>

<p>The Moon, for example, (not a planet I know) stabilises the Earth spin axis, preventing it from flipping, which would otherwise happen (on long time scales) with drastic consequences for the Earth climate and hence any life forms.</p>

<p>Jupiter (and to a much lesser degree the other outer planets) plays a significant role in the dynamics of smaller bodies (asteroids and meteroids), including absorbing them. If, for example, the meteroid and asteroid impacts on Earth were more frequent, that too would have drastic consequences for the climate and life.</p>

CC BY-SA 3.0
2015-02-06T09:58:31.520Z
2015-02-06T09:58:31.520Z
Walter
<p>Without just disregarding your question as one of a philosophical nature, the significance is irrelevant in the context of what you are asking. Other planets are a consequence of the evolution of our solar system - accretion of matter, gravitational influence, energy from the sun etc. - they aren't there for any 'reason'. Energy from other planets (and indeed other objects in our solar system) comes in the form of gravitational energy and light which is reflected off them emanating from the sun.  </p>

CC BY-SA 3.0
2015-02-06T09:43:17.077Z
2015-02-06T09:43:17.077Z
Phizzy
<p>Earth receives sunlight from Sun; in a similar way, do we receive any kind of energy from other planets?</p>

<p>My question is: We are dependent on sunlight, which is energy from Sun; similarly, are we dependent on other planets as well? What would happen if they weren't there?</p>

CC BY-SA 3.0
2015-02-06T09:41:10.693Z
Are you asking for the *reason* (that there are planets) or for their *purpose*?
Walter
CC BY-SA 3.0
2015-02-06T09:47:04.037Z
ok, my question is very broad, my question is we are dependent on the sunlight which is energy from Sun, similarly are we dependent on other planets as well. What if they are not there.
user804401
CC BY-SA 3.0
2015-02-06T09:58:54.343Z
@user804401 I would suggest you edit your question to make it more clear that you are asking what effects other planets might have on the earth, because that's actually an interesting question to ask.
David H
CC BY-SA 3.0
2015-02-07T02:25:28.517Z
I think asking what would happen if the other planets weren't there would be a much more concrete and answerable question. Why they exist and what there "significance" is are more or less unanswerable.
Keith Thompson
CC BY-SA 3.0
2015-02-11T19:22:36.653Z
I'm voting to put this question on hold. There seem to be two very different questions being asked: (1) *Why* do other planets exist (which I suggest is off-topic; it *might* be a better fit for http://philosophy.stackexchange.com/ or one of the sites that deal with religion); and (2) What effect do other planets have on us here on Earth (which would be a valid question for this site).
Keith Thompson
<solar-system><planet><life>
Why there are other planets in our solar system?
user804401
# Why there are other planets in our solar system?

(Asked by: username_0 on 2015-02-06)

Earth receives sunlight from Sun; in a similar way, do we receive any kind of energy from other planets?

My question is: We are dependent on sunlight, which is energy from Sun; similarly, are we dependent on other planets as well? What would happen if they weren't there?

**Tags:** solar-system, planet, life
> **Comments:**
> **username_1**: Are you asking for the *reason* (that there are planets) or for their *purpose*?  
> **username_0**: ok, my question is very broad, my question is we are dependent on the sunlight which is energy from Sun, similarly are we dependent on other planets as well. What if they are not there.  
> **username_2**: @user804401 I would suggest you edit your question to make it more clear that you are asking what effects other planets might have on the earth, because that's actually an interesting question to ask.  
> **username_3**: I think asking what would happen if the other planets weren't there would be a much more concrete and answerable question. Why they exist and what there "significance" is are more or less unanswerable.  
> **username_3**: I'm voting to put this question on hold. There seem to be two very different questions being asked: (1) *Why* do other planets exist (which I suggest is off-topic; it *might* be a better fit for http://philosophy.stackexchange.com/ or one of the sites that deal with religion); and (2) What effect do other planets have on us here on Earth (which would be a valid question for this site).  

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## 3 answers

### Answer by username_4 on 2015-02-09. Score: 3 | Accepted answer

Well without your big brother jupiter looking out for poor little earth then life on earth wouldn't be possible (most likely, but definitely not intelligent life as it has taken us millions of years to evolve to this point, and meteor collisions would increase at an alarming rate). You receive a force on your body from all the planets in the solar system and everything in the universe for that matter, but they are neglible compared to the force you feel from earth. "But Jupiter is so much bigger than earth how could its gravity be negligible?" Well the intensity of gravity is proportional to 1/distance^2 (one over distance squared) so the farther you are away from something the less gravitational effect it has on you, and earth is big enough that it is most likely the only gravitational effect your body will ever truly be aware of. However you can see the tidal effects caused by the moon. High tide low tide are created by the moon's gravity. I once heard a man say astrology (the arch nemesis of the astronomer) is based in the tidal affects on the heavy metals in one's body caused by the positioning of the planets at one's birth, which I had to admit made for a pretty convincing argument though I still don't read my horoscope.

> **Comments:**
> **username_3**: It's likely that Jupiter's influence has protected Earth from collisions (or not; I don't know what the latest scientific consensus on that is). But your answer implies that that's the *reason* that Jupiter exists. If that's what you mean to say, then I would ask for something to substantiate that claim. Are you assuming some intelligent design behind the structure of the Solar System? If that's not what you mean to say, then I suggest that this doesn't answer the question in its current form.  
> **username_5**: You should explain *why* Jupiter was so important. [This](https://en.wikipedia.org/wiki/Jupiter#Interaction_with_the_Solar_System) talks about it briefly.  
> **username_4**: Noon intelligent design the reason Jupiter exists is because that's how the cloud of matter accreted in the early solar system. Is this question philosophical?  

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### Answer by username_1 on 2015-02-06. Score: 7

Did you mean to ask

**Would life on Earth be possible if Earth was the only planet in the Solar system?**

The answer is **perhaps** *, we can only speculate and know too little about the evolution of the planetary system to give any firm answer.*

The Moon, for example, (not a planet I know) stabilises the Earth spin axis, preventing it from flipping, which would otherwise happen (on long time scales) with drastic consequences for the Earth climate and hence any life forms.

Jupiter (and to a much lesser degree the other outer planets) plays a significant role in the dynamics of smaller bodies (asteroids and meteroids), including absorbing them. If, for example, the meteroid and asteroid impacts on Earth were more frequent, that too would have drastic consequences for the climate and life.


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### Answer by username_6 on 2015-02-06. Score: 2

Without just disregarding your question as one of a philosophical nature, the significance is irrelevant in the context of what you are asking. Other planets are a consequence of the evolution of our solar system - accretion of matter, gravitational influence, energy from the sun etc. - they aren't there for any 'reason'. Energy from other planets (and indeed other objects in our solar system) comes in the form of gravitational energy and light which is reflected off them emanating from the sun.


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