The night sky in December 2024
Another year is coming to its end and we are almost in the middle of the longest nights of the year. Great opportunities for observing and imaging….provided the skies stay clear.
The Winter Solstice is on 22nd December, it is the time when the north pole points at it’s maximum tilt away from the Sun and becomes our shortest day. In many other cultures, including ancient ones in the UK it is associated with the death and rebirth of the Sun. Our nights will start to get shorter.
Meteor Showers
This month it is time for the Geminids to appear. Best seen between 4-20th December, peaking around 14th-15th December. It is usually a good meteor event, but sadly it’s timing this month is poor as it is at the Moon’s full phase.
See https://earthsky.org/astronomy-essentials/everything-you-need-to-know-geminid-meteor-shower/ for more detail.
It is thought that the Geminids origin lies with an asteroid called Phaethon.
A smaller shower, the Ursids, occurs 17th-26th December peaking around 22-23rd December. The centre is around Kochab (Beta Umi) and is associated with comet 8P/Tuttle. https://earthsky.org/astronomy-essentials/ursid-meteor-shower-active-around-winter-solstice/
The Moon
The new Moon starts on 1st December, reaching First Quarter on 9th December, Full Moon 15th December and Last Quarter on 22nd December.
The Planets
Venus: Increasingly bright in the west and reaching -4.4 mag, it ill be climbing to 15º by 21st December.
Mars: 18th December. Provided it is a clear day, yes day, there is a daylight occultation of Mars by a slightly waxing full Moon. Starting around 09:24 GMT and finishing about 10:15 GMT. However a clear vie is needed at the Moon is only 13º above the western horizon.
Jupiter: Will be in opposition on 7th December and extremely bright at mag -2.8.
Opposition means that Jupiter will reach its closest approach to the Earth and will be a +48 arc-second disc.
As Jupiter is at opposition this provides a great opportunity to see her four Galilean moons make both shadow transits as well a body transits across the face of our largest planet. Because the Moons will have the faces towards us and the Sun they should appear as objects brighter than the surface of the planet. This will happen on various days of the December. See https://theskylive.com/galilean-moons
There are events on 1st,3rd,4th, 6th, 8&9th, 10/11th 16th and 29th December.
Saturn: Will be at eastern quadrature on 4th December. On 6th December staring at 18:32GMT and finishing at 22:30 there is a shadow transit of Titan.
Uranus: An evening sky object, its retrograde motion is completed for the present time having been passing through Taurus, it will now enter Aries. A good evening object to try and observe.
Neptune: Is in the constellation of Pisces on 8th December.
The Constellations: Orion continues to make it’s winter march across our skies and well placed for both wide-field imaging as well as imaging the DSO around it such as the Rosette Nebula. The Pleiades, a favourite of mine, is also well positioned for imaging.
We see it as a warrior but in NZ the belt rises vertically above the Pacific horizon and the see its belt as a canoe seat.
The Plough now assumes a more vertical position at this time of the year, the Chinese called its seven stars the Seven Regulators as they saw it as a group of administrators to the Emperor controlling the sky. It is also a good time of the month to observe Perseus and Cassiopea, also putting the Double Cluster very high and good for imaging.
Keep looking up
Frank Dutton FRAS
