© NASA/JPL/MESSENGER

Mercury at aphelion

Dominic Ford, Editor
From the Inner Planets feed

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The sky at

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

Object Right Ascension Declination Constellation Angular Size
Mercury 17h01m50s -23°52' Ophiuchus 4.6"
Sun 17h01m -22°45' Ophiuchus 32'28"

The coordinates above are given in J2000.0.

From Cambridge, Mercury will not be readily observable since it will be very close to the Sun, at a separation of only 1° from it.

Begin typing the name of a town near to you, and then select the town from the list of options which appear below.
The sky on 08 December 2014
Sunrise
07:00
Sunset
16:10
Twilight ends
17:51
Twilight begins
05:19

16-day old moon
Waning Gibbous

94%

16 days old

Planets
Rise Culm. Set
Mercury 07:06 11:35 16:04
Venus 07:55 12:23 16:50
Moon 18:44 01:03 08:17
Mars 10:13 14:55 19:38
Jupiter 21:13 04:16 11:15
Saturn 05:25 10:20 15:15
All times shown in EST.

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 DE405 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

01 Nov 2014  –  Mercury at greatest elongation west
14 Jan 2015  –  Mercury at greatest elongation east
17 Jan 2015  –  Mercury reaches highest point in evening sky
18 Feb 2015  –  Mercury reaches highest point in morning sky

Image credit

© NASA/JPL/MESSENGER

Cambridge

Latitude:
Longitude:
Timezone:

42.38°N
71.11°W
EDT

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