The Night Sky in December 2004
Maps of the current night sky can be see by clicking HERE
Phases of the Moon
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| New Moon Saturday 12 |
First quarter Sunday 19 |
Full Moon Sunday 26 |
Last quarter Saturday 5 |
Monthly Highlights
December - Spot the International Space Station (ISS)
This month we have included a link for you to discover when the space station will be visible in the coming weeks. Typically, the space station can be seen just before dawn or just after sunset. Although it is dark, the Sun is not too far below the horizon and is able to light up the ISS. As the orbit only just gets up to the latitude of the UK it will usually be seen to the south, and is only visible for a minute or so at each sighting. The NASA Website link below gives details for several cities in the UK.
Find details of sighting possibilities from your location from: Location Index 
Conjunction of Mercury and Venus
A conjunction occurs when two heavenly bodies align in the sky. Just before dawn on the 27th of December, there is a chance to see three planets in the south-east. Mercury and Venus are close together (just over 1 degree away), just above the horizon, whilst the planet Mars is higher towards the south. Binoculars will help pick out Mercury but it is important to make sure you never look directly at the Sun, especially through binoculars.
The Planets
Click HERE and start the Electric Orrery to see where all the planets are today in relation to each other.
MercuryMercury is now passing between us and the Sun (where it is too difficult to see), but will become visible again towards the end of the month when you can see it rising just before the Sun. It reaches greatest elongation - separation from the Sun as seen from the Earth - on December 29th but will still be difficult to spot without binoculars. Remember that planets do not twinkle in the same way as stars, which makes it much easier for us to spot them. On the 27th December, Mercury will be only 1.25 degrees from Venus.
VenusVenus continues to dominate the pre-dawn sky, rising in the east about 2 hours before the Sun and shining steadily at 10 times the brightness of the brightest star (Sirius). The brightness stays almost constant this month as the reducing angular size (Venus getting closer to the Sun) is compensated by the larger surface area that we see illuminated, which increases from 88 to 93% during the month. Venus remains too low in the sky for the Liverpool Telescope to observe but will be visible to the naked eye.
MarsMars is now visible in the pre-dawn sky in the east, but shines with only one tenth the brightness of Venus and appears as a salmon-pink or orange dot through binoculars. At the beginning of the month it will lie just 3.5 degrees away from Venus and on December 5th will be within just 1.5 degrees. As with Venus, Mercury and Jupiter, Mars is too low down in the sky for the Liverpool Telescope to observe.
JupiterJupiter may be easily seen above the eastern horizon in the hours before dawn this month. As Jupiter is now on the far side of the Sun (try checking this using the Electric Orrery), its brightness will struggle to rise above 20% that of Venus, making it a little hard to pick out with binoculars - assuming you were wanting to get up that early! Again, this is another of the planets that remain too low in the sky to be observed with the Liverpool telescope.
SaturnSaturn is currently passing through the constellation of Gemini and on the 27th will be just below the almost full Moon. It is already rising in the east-north-east at around 8:30pm, but by the end of the month, will rise just after sunset. The rings are still nice and open, making Saturn a beautiful sight if observing through the Liverpool telescope. A 'Go Observing' image should easily show its brightest moon, Titan, but after processing should reveal at least three more (Rhea and Dione are easiest and Tethys less so). Try to submit an observation request before your Christmas holidays.
Constellation of the monthEach month, new constellations are highlighted for you to identify in the night sky.This month, try to find the constellations of Orion and Ursa Major (also known as the 'Plough'). Note how the two stars on the southern edge of Ursa Major point towards the North Star (also known as the 'Pole' star or 'Polaris'). The North Star is the only star in the sky which doesn't move during the night. This is because it is located directly above the rotation axis of the Earth. See if you can locate the North Star.
 December Night Sky Orion (shown below) is one of the most famous constellations, which from mythology is said to take the form of a hunter. At UK latitudes, Orion is seen in the south of the sky in early evening during winter and spring. Orion contains some amazing stars including Betelgeuse (top left 'shoulder'), a red star hundreds of times the size of our Sun, and Rigel (bottom right 'knee') the seventh brightest star in the heavens. Orion's belt (the three stars in the middle) also contains a very famous object called the Orion Nebula, which is a vast starlit cloud of dust and gases where new stars are being born.
 Constellation of Orion Finally, try and spot the 'Seven Sisters' star cluster (indicated on the December SkyMap above). This will appear as a fuzzy patch above and to the right of Orion, and although we can only see 6 or 7 stars with the naked eye, there are actually close to 400 stars in this open cluster. In astronomical terms, these are really young stars, being only 100 hundred million years old (the Sun is middle-aged at 4500 million years), and have only recently formed from a large cloud of dust and gas (or nebula). If your schools is registered, you can observe a nebula with the Liverpool Telescope using Go Observing. You will need a username and password from your teacher. an idea . . . Why not keep a note book of your observations of the night sky throughout the year. You will soon get to know your way round the heavens and this will help when you are using the Liverpool Telescope.
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