Mercury reaches greatest elongation east on April 18, 2016. Best chance to see the planet in the evening sky from northern locations this year.

Mercury reaches greatest elongation east (GEE) on April 18th when it's positioned 19.9 degrees from the Sun. The nearest planet to the Sun will be visible during April low down above the west-northwestern horizon shortly after sunset. This months apparition offers the best opportunity (evening) for observers at northern latitudes to spot the elusive planet this year. From equatorial regions Mercury is also visible during April but from mid-southern latitudes unfortunately not.

Observing Mercury

When searching for Mercury a clear unobstructed view of the west-northwestern horizon is essential. Observers should be able to spot the planet about 45 minutes after sunset against the twilight backdrop. What is surprising when looking for Mercury is how close the planet clings to the horizon. For example from London, England (51.5 degrees N) Mercury will be 6 degrees above the horizon 45 minutes after sunset on April 8th. On this evening the nearby thin nearby waxing crescent Moon will acts as a convenient marker. A good period to look is between April 13th and April 23rd when Mercury will be at it's highest in the sky about 10 degrees above the horizon. After that it's altitude decreases quickly until it's lost to the bright twilight near the end of the month. Observers should note that the planet is at its brightest at the start of the month - it decreases from mag. -1.4 to +2.1 as the visibility period progresses.

The diagram below shows the altitude of Mercury 45 minutes after sunset when viewed from London, England. The view will be similar from other northern temperate locations.

Mercury Data Table April 2016

Date Right Ascension Declination App. Mag. App. Size Illumin. (%) Dist. from Earth (AU) Constellation April 01 01h 13m 49.1s 07d 48m 19.3s -1.5 05.3" 94 1.266 Pisces April 02 01h 21m 06.6s 08d 44m 10.2s -1.5 05.4" 92 1.250 Pisces April 03 01h 28m 21.8s 09d 39m 17.3s -1.4 05.5" 90 1.233 Pisces April 04 01h 35m 33.5s 10d 33m 26.9s -1.3 05.5" 88 1.214 Pisces April 05 01h 42m 40.6s 11d 26m 25.6s -1.3 05.6" 85 1.194 Pisces April 06 01h 49m 41.7s 12d 18m 00.0s -1.2 05.7" 83 1.174 Aries April 07 01h 56m 35.7s 13d 07m 57.1s -1.1 05.8" 80 1.152 Aries April 08 02h 03m 21.1s 13d 56m 04.8s -1.0 06.0" 76 1.129 Aries April 09 02h 09m 56.7s 14d 42m 12.0s -1.0 06.1" 73 1.105 Aries April 10 02h 16m 21.0s 15d 26m 08.6s -0.9 06.2" 69 1.081 Aries April 11 02h 22m 32.8s 16d 07m 46.1s -0.8 06.4" 66 1.056 Aries April 12 02h 28m 31.0s 16d 46m 57.0s -0.7 06.5" 62 1.031 Aries April 13 02h 34m 14.2s 17d 23m 35.3s -0.6 06.7" 59 1.006 Aries April 14 02h 39m 41.6s 17d 57m 36.2s -0.5 06.9" 55 0.980 Aries April 15 02h 44m 52.0s 18d 28m 55.9s -0.4 07.0" 51 0.955 Aries April 16 02h 49m 44.5s 18d 57m 31.8s -0.3 07.2" 48 0.929 Aries April 17 02h 54m 18.2s 19d 23m 21.9s -0.2 07.4" 44 0.904 Aries April 18 02h 58m 32.5s 19d 46m 24.9s 0.0 07.6" 41 0.880 Aries April 19 03h 02m 26.5s 20d 06m 40.1s 0.1 07.9" 37 0.855 Aries April 20 03h 05m 59.7s 20d 24m 07.1s 0.3 08.1" 34 0.831 Aries April 21 03h 09m 11.4s 20d 38m 46.0s 0.5 08.3" 31 0.808 Aries April 22 03h 12m 01.4s 20d 50m 36.7s 0.6 08.6" 28 0.786 Aries April 23 03h 14m 29.0s 20d 59m 39.8s 0.8 08.8" 25 0.764 Aries April 24 03h 16m 34.2s 21d 05m 55.6s 1.1 09.0" 23 0.743 Aries April 25 03h 18m 16.7s 21d 09m 25.1s 1.3 09.3" 20 0.724 Aries April 26 03h 19m 36.6s 21d 10m 09.2s 1.5 09.5" 17 0.705 Aries April 27 03h 20m 34.1s 21d 08m 09.5s 1.8 09.8" 15 0.686 Aries April 28 03h 21m 09.3s 21d 03m 28.0s 2.1 10.0" 13 0.669 Aries April 29 03h 21m 23.0s 20d 56m 07.6s 2.4 10.3" 11 0.654 Aries April 30 03h 21m 15.8s 20d 46m 12.0s 2.7 10.5" 09 0.639 Aries

See also

The Planets this Month - April 2016