© NASA/JPL/MESSENGER

Mercury at dichotomy

Dominic Ford, Editor
From the Inner Planets feed

Objects: Mercury
Please wait
Loading 0/4
Click and drag to rotate
Mouse wheel to zoom in/out
Touch with mouse to dismiss
The sky at

Mercury will reach half phase in its Dec 2068–Jan 2069 evening apparition. It will be shining brightly at mag -0.4.

From Cambridge , this apparition will not be one of the most prominent and very difficult to observe, reaching a peak altitude of 12° above the horizon at sunset on 26 Dec 2068.

Begin typing the name of a town near to you, and then select the town from the list of options which appear below.

Dec 2068–Jan 2069 evening apparition of Mercury

08 Nov 2068 – Mercury at superior solar conjunction
21 Dec 2068 – Mercury at greatest elongation east
24 Dec 2068 – Mercury at dichotomy
24 Dec 2068 – Mercury at highest altitude in evening sky
07 Jan 2069 – Mercury at inferior solar conjunction

A graph of the phase of Mercury is available here.

Apparitions of Mercury

16 Jun 2068 – Morning apparition
27 Aug 2068 – Evening apparition
08 Oct 2068 – Morning apparition
21 Dec 2068 – Evening apparition
30 Jan 2069 – Morning apparition
11 Apr 2069 – Evening apparition
29 May 2069 – Morning apparition

Observing Mercury

Mercury's orbit lies closer to the Sun than the Earth's, meaning that it always appears close to the Sun and is lost in the Sun's glare much of the time.

It is observable for only a few weeks each time it reaches greatest separation from the Sun – moments referred to as greatest elongation. These apparitions repeat roughly once every 3–4 months.

Mercury's phase

Mercury's phase varies depending on its position relative to the Earth. When it passes between the Earth and Sun, for example, the side that is turned towards the Earth is entirely unilluminated, like a new moon.

Conversely, when it lies opposite to the Earth in its orbit, passing almost behind the Sun, it appears fully illuminated, like a full moon. However, at this time it is also at its most distant from the Earth, so it is actually fainter than at other times.

Mercury shows an intermediate half phase – called dichotomy – at roughly the same moment that it appears furthest from the Sun, at greatest elongation. The exact times of the two events may differ by a few days, only because Mercury's orbit is not quite perfectly aligned with the ecliptic.

Mercury's position

The coordinates of Mercury when it reaches dichotomy will be:

Object Right Ascension Declination Constellation Angular Size
Mercury 19h38m10s 22°36'S Sagittarius 7.3"
Sun 18h12m 23°23'S Sagittarius 32'31"

The coordinates above are given in J2000.0.

The sky on 23 Nov 2024

The sky on 23 November 2024
Sunrise
06:43
Sunset
16:15
Twilight ends
17:54
Twilight begins
05:03

22-day old moon
Waning Crescent

42%

22 days old

Planets
Rise Culm. Set
Mercury 08:33 12:55 17:17
Venus 10:09 14:32 18:54
Moon 23:09 06:06 12:50
Mars 20:36 04:03 11:30
Jupiter 17:09 00:40 08:11
Saturn 12:58 18:29 23:59
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 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

21 Dec 2068  –  Mercury at greatest elongation east
25 Dec 2068  –  Mercury at highest altitude in evening sky
24 Jan 2069  –  Mercury at highest altitude in morning sky
30 Jan 2069  –  Mercury at greatest elongation west

Image credit

© NASA/JPL/MESSENGER

Share

Cambridge

Latitude:
Longitude:
Timezone:

42.38°N
71.11°W
EST

Color scheme