Neptune's 164.9-year orbit around the Sun will carry it to its furthest point to the Sun – its aphelion – at a distance of 30.28 AU.
In practice, however, Neptune's orbit is very close to circular; its distance from the Sun only varies by about 1.7% between perihelion and aphelion. This means that the difference in the amount of heat and light it receives from the Sun between aphelion and perihelion is extremely small.
Finding Neptune
Neptune's distance from the Sun doesn't affect its appearance. From Fairfield, at the moment of aphelion it will not be observable – it will reach its highest point in the sky during daytime and will be no higher than 17° above the horizon at dawn.
A chart of the path of Neptune across the sky in 1980 can be found here, and a chart of its rising and setting times here.
The position of Neptune at the moment it passes aphelion will be:
| Object | Right Ascension | Declination | Constellation | Magnitude | Angular Size |
| Neptune | 17h26m30s | 21°52'S | Ophiuchus | 8.0 | 2.2" |
The coordinates above are given in J2000.0.
The sky on 8 May 2024
| The sky on 8 May 2024 | ||||||||||||||||||||||||||||||||||
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0% 30 days old |
All times shown in EDT.
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Source
The circumstances of this event were computed using the DE430 planetary ephemeris published by the Jet Propulsion Laboratory (JPL).
This event was automatically generated by searching the ephemeris for planetary alignments which are of interest to amateur astronomers, and the text above was generated based on an estimate of your location.
Related news
| 30 Aug 1979 | – Neptune ends retrograde motion |
| 24 Mar 1980 | – Neptune enters retrograde motion |
| 11 Jun 1980 | – Neptune at opposition |
| 31 Aug 1980 | – Neptune ends retrograde motion |
Image credit
© NASA/Voyager 2