Mercury at aphelion

Dominic Ford, Editor
From the Inner Planets feed


Objects: Mercury

Mercury's 88-day orbit around the Sun will carry it to its furthest point to the Sun – its aphelion – at a distance of 0.47 AU.

Unlike most of the planets, which follow almost exactly circular orbits around the Sun only varying in their distance from the Sun by a few percent, Mercury has a significantly elliptical orbit.

Its distance from the Sun varies between 0.307 AU at perihelion (closest approach to the Sun), and 0.467 AU at aphelion (furthest recess from the Sun). This variation, of over 50%, means that its surface receives over twice as much energy from the Sun at perihelion as compared to aphelion.

However, this makes little difference to Mercury's telescopic appearance, since little if any detail on its surface can be resolved by ground-based telescopes. Although its changing seasons have an incredible effect upon its surface temperatures, there is little change that is visible to amateur observers.

The position of Mercury at the moment it passes aphelion will be:

Object Right Ascension Declination Constellation Angular Size
Mercury 02h16m20s 10°55'N Aries 10.9"
Sun 03h24m 18°37'N Taurus 31'39"

The coordinates above are given in J2000.0.

From Fairfield, Mercury will not be observable – it will reach its highest point in the sky during daytime and will be 5° below the horizon at dawn.

The sky on 14 May 2023

The sky on 14 May 2023
Sunrise
05:33
Sunset
20:02
Twilight ends
21:56
Twilight begins
03:40


Waning Crescent

21%

24 days old

Planets
Rise Culm. Set
Mercury 04:58 11:40 18:23
Venus 08:12 15:56 23:41
Moon 03:16 08:48 14:31
Mars 09:49 17:18 00:46
Jupiter 04:35 11:14 17:54
Saturn 02:33 07:58 13:23
All times shown in EDT.

Warning

Never attempt to point a pair of binoculars or a telescope at an object close to the Sun. Doing so may result in immediate and permanent blindness.

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

11 Apr 2023  –  Mercury at greatest elongation east
29 May 2023  –  Mercury at greatest elongation west
05 Jun 2023  –  Mercury at highest altitude in morning sky
29 Jul 2023  –  Mercury at highest altitude in evening sky

Image credit

© NASA/JPL/MESSENGER

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