September Night Sky.

sept17 sky

The sky at 00h on the 17th. September.

Full Moon: 6th. September. New Moon: 20th. September.

Autumnal Equinox: 22nd. September.

Mercury reaches greatest Western elongation on the 12th. meaning it rises shortly before the Sun. It is a reasonably bright magnitude -0.4. It will be low down at sunrise so you will need a clear Eastern horizon to see this elusive body. The thin crescent of the waning moon passes nearby on the 19th.

Above Mercury lie two other planets; Venus is a bright -3.9; the moon passes just south on the 18th. The moon also passes very close to the brightest star in Leo, Regulus, the same night. Mars lies between Mercury and Venus and is the faintest of the planets at magnitude 1.8.

Of the giant planets Saturn is the most easily visible; shining between magnitude +0.4 and +0.5 in Ophiuchus. The moon will pass just above it on the 26th and 27th. Saturn remains low in the sky and sets around 9:45 pm.

For more of a challenge why not try to find the distant planets nicknamed the ‘Ice Giants’? Uranus lies in Pisces and is just below naked eye visibility, at magnitude +5.7, but a pair of binoculars should show it as a round object. It is visible most of the night – rising at 7.20 pm by the end of the month.

Neptune will be visible for a week or so after the 6th. It is much feinter at magnitude +7.8 so will be more of a challenge. It is low in the sky in Aquarius. The ‘N’ on the map marks the approximate area in the sky to look next to the star λ Aquarii. The full moon is nearby on the 6th but is so bright it washes out the planet.


On This Day…


165 Years Ago – September 5th. 1857: Konstantin E. Tsiolkovsky, the father of rocketry was born in village of Izhevsk, in the USSR.

55 Years Ago – September 12th. 1962: President John F. Kennedy gives his famous address at Rice University on the nation’s space effort. In this well-known speech, Kennedy stated that we explore space not because it is easy but because it is difficult. This was the beginning of the journey to land men on the moon.

40 Years Ago – September 5th. 1977: Voyager 1was launched from Cape Canaveral on a Titan IIIE-Centaur launch vehicle. This was the beginning of the ‘Grand Tour’ of the planets.

September 29th. 1977: The USSR launched the Salyut-6 space station aboard Proton K rocket from Baikonur.

Tsiolkovsky                                     John F, Kennedy

Published in: on September 14, 2017 at 15:58  Leave a Comment