<p>There is method for finding extrasolar planets called <a href="https://en.wikipedia.org/wiki/Transit-timing_variation" rel="nofollow noreferrer">Transit-timing variation</a>. If I understood correctly, exoplanets accelerate or decelerate each other (according on their position), so we can observe irregularities in transit times of some exoplanet.</p>
<p>Now, for our solar system, can we observe similar effect here? Why time of Earth's orbit around Sun is always 365.256 days, even though other planets are always in different places? Shouldn't Earth year be always differently long?</p>

CC BY-SA 4.0
2020-11-28T10:39:08.283Z
The Sidereal year ( on average 365.256) isn't constant: see https://astronomy.stackexchange.com/questions/13041/is-the-duration-of-a-sidereal-year-stable.  It doesn't change much
James K
CC BY-SA 4.0
2020-11-28T11:17:37.093Z
I found a standard deviation of 0.004 day while investigating [this question](/q/34737).
Mike G
<orbit><planet><gravity><earth><velocity>
Do planets have effect on velocity of Earth?
Michal
# Do planets have effect on velocity of Earth?

(Asked by: username_0 on 2020-11-28)

There is method for finding extrasolar planets called [Transit-timing variation](https://en.wikipedia.org/wiki/Transit-timing_variation). If I understood correctly, exoplanets accelerate or decelerate each other (according on their position), so we can observe irregularities in transit times of some exoplanet.

Now, for our solar system, can we observe similar effect here? Why time of Earth's orbit around Sun is always 365.256 days, even though other planets are always in different places? Shouldn't Earth year be always differently long?

**Tags:** orbit, planet, gravity, earth, velocity

> **Comments:**
> **username_1**: The Sidereal year ( on average 365.256) isn't constant: see https://astronomy.stackexchange.com/questions/13041/is-the-duration-of-a-sidereal-year-stable.  It doesn't change much  
> **username_2**: I found a standard deviation of 0.004 day while investigating [this question](/q/34737).  

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## 0 answers

