<p>Whether they are in a line is irrelevant.</p>

<p>All masses have a gravitational effect. The gravitational effect of planets causes perturbation from an elliptical orbit. The gravitational pull of Jupiter (and to a lesser extent Saturn and the other planets) causes the Earth's orbit to change from nearly circular to slightly elliptical then back to circular. The planets also cause the angle that the elliptical orbit makes to rotate around the sun. Again this mostly caused by Jupiter. </p>

<p>The eccentricity varies with roughly 100000 year period, and the angle varies over 112000 years. </p>

<p>These effects are well understood and can be observed and measured. However alignments are inconsequential. Alignments of the planets have no effect on the Earth. They do not cause earthquakes. They do not cause volcanos.</p>

<p>The moon does have significant effects, as it is the primary cause of tides.</p>

CC BY-SA 3.0
2018-02-26T21:50:47.270Z
2018-02-26T21:50:47.270Z
James K
<p><strong>TL;DR:</strong> No. Well, yes, but they are negligible.</p>
<hr />
<p>Full answer: a conjunction like this 'nearly' happened on May 5th, 2000. NASA published <a href="https://nssdc.gsfc.nasa.gov/planetary/alignment.html" rel="nofollow noreferrer">an article</a> about this event, stating:</p>
<blockquote>
<p>For example, the combined gravitational effect of all the planets together is much less than the effect of the Sun or the Moon on the Earth.</p>
</blockquote>
<p>and</p>
<blockquote>
<p>While unusual, such alignments have happened in the past without any consequences. The planets are simply too far away to have an effect on anything here on Earth - except our imaginations.</p>
</blockquote>
<p>For hard numbers, see <a href="http://www.tkcs-collins.com/truman/conjunct/conjunct.shtml" rel="nofollow noreferrer">this article by Truman Collins</a> which is linked there:</p>
<blockquote>
<h3>Conclusion</h3>
<p>What I discovered was that the tidal forces exerted on Earth from the five planets on the other side of the Sun are vastly smaller than those exerted by the Moon or the Sun. In fact, with the planets in the position they will be in on the big day, the largest tidal force from one of them will be from Jupiter, and it is about one five hundred thousandth the size of the tidal force exerted by the Moon on an average day!</p>
</blockquote>

CC BY-SA 3.0
2018-02-27T01:07:48.997Z
I'd not say "no". "Yes, but the effects are very small" is more accurate.
Allure
CC BY-SA 3.0
2018-02-27T12:19:33.397Z
I think it is better to point out that from the perspective of gravitational influence, there is nothing special about a conjunction, or planets "lining up". Popular media likes to use arbitrary configurations and arbitrarily accurate times to generate click bait, but in terms of gravity, the influence is always there, and it varies only very gradually.
uhoh
CC BY-SA 3.0
2018-02-26T21:43:19.780Z
2018-02-27T09:23:52.010Z
2020-06-17T09:47:40.653Z
Glorfindel
<p>Let say Mercury, Venus, the Moon were all in alignment between the Earth and Sun. They are all closest to each other in respective elliptical orbit.  On the other side of the Sun you have the rest of the planets. </p>

<p>Would their gravity combine to have any gravitational effects on the Earth?
Or are they all too far away?</p>

CC BY-SA 3.0
2018-02-27T00:26:53.910Z
Muze, the simple answer is they have a **tiny** effect.  Essentially "no" effect.  It makes little difference how they are aligned.
Fattie
<the-sun><planet><gravity><solar-system><orbital-mechanics>
Do other planets affect the Earth?
Muze
# Do other planets affect the Earth?

(Asked by: username_0 on 2018-02-26)

Let say Mercury, Venus, the Moon were all in alignment between the Earth and Sun. They are all closest to each other in respective elliptical orbit. On the other side of the Sun you have the rest of the planets.

Would their gravity combine to have any gravitational effects on the Earth?
Or are they all too far away?

**Tags:** the-sun, planet, gravity, solar-system, orbital-mechanics
> **Comments:**
> **username_1**: Muze, the simple answer is they have a **tiny** effect.  Essentially "no" effect.  It makes little difference how they are aligned.  

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## 2 answers

### Answer by username_3 on 2018-02-26. Score: 4 | Accepted answer

**TL;DR:** No. Well, yes, but they are negligible.

---

Full answer: a conjunction like this 'nearly' happened on May 5th, 2000. NASA published [an article](https://nssdc.gsfc.nasa.gov/planetary/alignment.html) about this event, stating:

> For example, the combined gravitational effect of all the planets together is much less than the effect of the Sun or the Moon on the Earth.

and

> While unusual, such alignments have happened in the past without any consequences. The planets are simply too far away to have an effect on anything here on Earth - except our imaginations.

For hard numbers, see [this article by Truman Collins](http://www.tkcs-collins.com/truman/conjunct/conjunct.shtml) which is linked there:

> ### Conclusion
>
> What I discovered was that the tidal forces exerted on Earth from the five planets on the other side of the Sun are vastly smaller than those exerted by the Moon or the Sun. In fact, with the planets in the position they will be in on the big day, the largest tidal force from one of them will be from Jupiter, and it is about one five hundred thousandth the size of the tidal force exerted by the Moon on an average day!

> **Comments:**
> **username_4**: I'd not say "no". "Yes, but the effects are very small" is more accurate.  
> **username_5**: I think it is better to point out that from the perspective of gravitational influence, there is nothing special about a conjunction, or planets "lining up". Popular media likes to use arbitrary configurations and arbitrarily accurate times to generate click bait, but in terms of gravity, the influence is always there, and it varies only very gradually.  

---

### Answer by username_2 on 2018-02-26. Score: 4

Whether they are in a line is irrelevant.

All masses have a gravitational effect. The gravitational effect of planets causes perturbation from an elliptical orbit. The gravitational pull of Jupiter (and to a lesser extent Saturn and the other planets) causes the Earth's orbit to change from nearly circular to slightly elliptical then back to circular. The planets also cause the angle that the elliptical orbit makes to rotate around the sun. Again this mostly caused by Jupiter.

The eccentricity varies with roughly 100000 year period, and the angle varies over 112000 years.

These effects are well understood and can be observed and measured. However alignments are inconsequential. Alignments of the planets have no effect on the Earth. They do not cause earthquakes. They do not cause volcanos.

The moon does have significant effects, as it is the primary cause of tides.


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