<p>There are several scenarios: An Earth-Venus <a href="http://en.wikipedia.org/wiki/Double_planet" rel="nofollow">binary</a> would be possible, or <a href="http://arxiv.org/abs/1207.5250" rel="nofollow">coplanar</a> prograde or <a href="http://en.wikipedia.org/wiki/Orbital_inclination" rel="nofollow">inclined</a> up to <a href="http://en.wikipedia.org/wiki/Retrograde_motion" rel="nofollow">retrograde</a> on <a href="http://en.wikipedia.org/wiki/Orbital_resonance" rel="nofollow">resonant</a> or <a href="http://www.univie.ac.at/adg/Conferences/hcm8/talks/hadjidemetriou.pdf" rel="nofollow">non-resonant</a> orbits, <a href="http://en.wikipedia.org/wiki/Elliptic_orbit" rel="nofollow">elliptic</a> or almost <a href="http://en.wikipedia.org/wiki/Circular_orbit" rel="nofollow">circular</a>.</p>

<p>One option would be a <a href="http://www.ualberta.ca/~urban/Samples/Stars/Coorbitals/images/strobe.mpg" rel="nofollow">co-orbital scenario</a>, which is described in more detail <a href="http://www.ualberta.ca/~urban/Samples/Stars/Coorbitals/Coorbitals.htm" rel="nofollow">here</a>. The latter would allow Earth and Venus to stay both in the habitable zone. But the effects for Earth could be very remarkable in some cases: Seasons would change over time, since <a href="http://en.wikipedia.org/wiki/Orbital_eccentricity" rel="nofollow">eccentricity</a> of Earth's orbit would change. If Earth and Venus would follow a <a href="http://en.wikipedia.org/wiki/Horseshoe_orbit" rel="nofollow">horseshoe orbit</a>, we would get variations in the length of a year.</p>

<p><a href="http://link.springer.com/article/10.1007/s10569-010-9288-0" rel="nofollow">Co-orbital systems</a> can become instable by the gravity of other planets.</p>

<p>In the long run <a href="http://arxiv.org/abs/1306.4293" rel="nofollow">tidal forces may lead to a collision of the two co-orbiting planets</a>.</p>

CC BY-SA 3.0
2014-02-22T19:49:36.030Z
2014-02-22T19:49:36.030Z
Gerald
<p>Changes on Earth:</p>

<p>Except for possible tides and possible eclipses, if it were near enough, no.</p>

<p>Changes on Earth's orbit:</p>

<p>Venus would establish some resonance with Earth's orbit, if it were near enough or in one of the exact possible spots. This will not have a major impact except on year's lenght and Sun illumination on Earth.</p>

CC BY-SA 3.0
2014-01-23T09:35:16.650Z
I do not understand why the downvote.
Envite
CC BY-SA 3.0
2014-01-22T19:40:34.113Z
2014-01-22T19:40:34.113Z
Envite
<p>If Venus was entirely inside the habitable zone, or life zone, would its proximity to the Earth provoke any remarkable changes to the Earth? </p>

CC BY-SA 3.0
2014-01-22T16:30:25.350Z
I have problems understanding what the question is. If Venus was in the Goldilocks zone, then... what about it? Venus is actually really close to this habitable zone and in fact touches it on its aphelion, but it's not merely the distance to the star that defines its habitability. In Venus' case, it's its runaway greenhouse effects of its thick atmosphere and the fact that it rotates slower on its own axis than it does around the Sun. It would still remain uninhabitable even if it was co-orbital with Earth.
TildalWave
CC BY-SA 3.0
2014-01-22T16:35:04.530Z
Is not the distance beetween Venus and the Sun, but beetween Earth and Venus, since we are in the Goldilocks zone and Venus not, if Venus were inside too, the Earth would suffer any changes because the gravity of Venus?
JeanPaul
CC BY-SA 3.0
2014-01-22T16:41:46.173Z
Well yes, but that again depends on where exactly it would be. If it was much closer to Earth, the two planets would be a subject to each other's tidal forces and eventually establish an orbital resonance, increasing Earth's orbital energy (higher orbit) and decreasing the one from Venus (lower orbit). I'm not sure where this energy to increase Venus' semi-major axis would come from, though?
TildalWave
CC BY-SA 3.0
2014-01-22T19:53:29.993Z
Loosely related, [this](http://twistedsifter.com/2013/05/if-other-planets-were-as-close-to-earth-as-the-moon/) is what Venus would look like from earth if it was as close as the moon.
Eduardo Serra
<planet><venus>
Would Venus have any significant effects on Earth if its orbit were entirely within the habitable zone?
JeanPaul
# Would Venus have any significant effects on Earth if its orbit were entirely within the habitable zone?

(Asked by: username_0 on 2014-01-22)

If Venus was entirely inside the habitable zone, or life zone, would its proximity to the Earth provoke any remarkable changes to the Earth?

**Tags:** planet, venus
> **Comments:**
> **username_1**: I have problems understanding what the question is. If Venus was in the Goldilocks zone, then... what about it? Venus is actually really close to this habitable zone and in fact touches it on its aphelion, but it's not merely the distance to the star that defines its habitability. In Venus' case, it's its runaway greenhouse effects of its thick atmosphere and the fact that it rotates slower on its own axis than it does around the Sun. It would still remain uninhabitable even if it was co-orbital with Earth.  
> **username_0**: Is not the distance beetween Venus and the Sun, but beetween Earth and Venus, since we are in the Goldilocks zone and Venus not, if Venus were inside too, the Earth would suffer any changes because the gravity of Venus?  
> **username_1**: Well yes, but that again depends on where exactly it would be. If it was much closer to Earth, the two planets would be a subject to each other's tidal forces and eventually establish an orbital resonance, increasing Earth's orbital energy (higher orbit) and decreasing the one from Venus (lower orbit). I'm not sure where this energy to increase Venus' semi-major axis would come from, though?  
> **username_2**: Loosely related, [this](http://twistedsifter.com/2013/05/if-other-planets-were-as-close-to-earth-as-the-moon/) is what Venus would look like from earth if it was as close as the moon.  

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## 2 answers

### Answer by username_3 on 2014-02-22. Score: 1 | Accepted answer

There are several scenarios: An Earth-Venus [binary](http://en.wikipedia.org/wiki/Double_planet) would be possible, or [coplanar](http://arxiv.org/abs/1207.5250) prograde or [inclined](http://en.wikipedia.org/wiki/Orbital_inclination) up to [retrograde](http://en.wikipedia.org/wiki/Retrograde_motion) on [resonant](http://en.wikipedia.org/wiki/Orbital_resonance) or [non-resonant](http://www.univie.ac.at/adg/Conferences/hcm8/talks/hadjidemetriou.pdf) orbits, [elliptic](http://en.wikipedia.org/wiki/Elliptic_orbit) or almost [circular](http://en.wikipedia.org/wiki/Circular_orbit).

One option would be a [co-orbital scenario](http://www.ualberta.ca/~urban/Samples/Stars/Coorbitals/images/strobe.mpg), which is described in more detail [here](http://www.ualberta.ca/~urban/Samples/Stars/Coorbitals/Coorbitals.htm). The latter would allow Earth and Venus to stay both in the habitable zone. But the effects for Earth could be very remarkable in some cases: Seasons would change over time, since [eccentricity](http://en.wikipedia.org/wiki/Orbital_eccentricity) of Earth's orbit would change. If Earth and Venus would follow a [horseshoe orbit](http://en.wikipedia.org/wiki/Horseshoe_orbit), we would get variations in the length of a year.

[Co-orbital systems](http://link.springer.com/article/10.1007/s10569-010-9288-0) can become instable by the gravity of other planets.

In the long run [tidal forces may lead to a collision of the two co-orbiting planets](http://arxiv.org/abs/1306.4293).


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### Answer by username_4 on 2014-01-22. Score: 1

Changes on Earth:

Except for possible tides and possible eclipses, if it were near enough, no.

Changes on Earth's orbit:

Venus would establish some resonance with Earth's orbit, if it were near enough or in one of the exact possible spots. This will not have a major impact except on year's lenght and Sun illumination on Earth.

> **Comments:**
> **username_4**: I do not understand why the downvote.  

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