<ol>
<li><p>What is the ecliptic longitude of the aphelion of each of the solar planets (Moon, Mercury, Venus, Earth, Mars, Jupiter, Saturn) currently in 2021 and from the observer's point of view on the earth? Please note I don't want to know their distances from the sun at their states of aphelion but their locations on the ecliptic while they are in aphelion states.</p>
</li>
<li><p>Does earth's axial precession cause the ecliptic longitude of planets' aphelions to change?</p>
</li>
</ol>

CC BY-SA 4.0
2021-08-18T14:53:02.383Z
I don't understand what you mean the aphelion of the moon.  The moon is a satellite of the Earth.
James K
CC BY-SA 4.0
2021-08-19T08:53:21.467Z
The heliocentric ecliptic longitude & latitude is fairly easy to calculate, but the geocentric is rather messy.
PM 2Ring
CC BY-SA 4.0
2021-08-19T08:57:14.833Z
However, it doesn't make sense to calculate the geocentric ecliptic  coords of the Earth.
PM 2Ring
CC BY-SA 4.0
2021-08-19T09:05:15.477Z
The axial precession causes the whole geocentric ecliptic coordinate grid to "wobble", but that has a period of ~26,000 years. On a much shorter time scale, for points inside the Solar system, there's parallax due to Earth's annual motion around the Sun.
PM 2Ring
<solar-eclipse><precession><zodiac>
Solar planets' aphelion longitudes in 2021?
Jade R.
# Solar planets' aphelion longitudes in 2021?

(Asked by: username_0 on 2021-08-18)

1. What is the ecliptic longitude of the aphelion of each of the solar planets (Moon, Mercury, Venus, Earth, Mars, Jupiter, Saturn) currently in 2021 and from the observer's point of view on the earth? Please note I don't want to know their distances from the sun at their states of aphelion but their locations on the ecliptic while they are in aphelion states.
2. Does earth's axial precession cause the ecliptic longitude of planets' aphelions to change?

**Tags:** solar-eclipse, precession, zodiac

> **Comments:**
> **username_1**: I don't understand what you mean the aphelion of the moon.  The moon is a satellite of the Earth.  
> **username_2**: The heliocentric ecliptic longitude & latitude is fairly easy to calculate, but the geocentric is rather messy.  
> **username_2**: However, it doesn't make sense to calculate the geocentric ecliptic  coords of the Earth.  
> **username_2**: The axial precession causes the whole geocentric ecliptic coordinate grid to "wobble", but that has a period of ~26,000 years. On a much shorter time scale, for points inside the Solar system, there's parallax due to Earth's annual motion around the Sun.  

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## 0 answers

