The Night Sky in February 2006
Looking at the night sky with the naked eye or using a small telescope can be fascinating, so each month these notes keep you up-to-date with unfolding events.Maps of the current night sky can be seen by clicking HERE
Phases of the Moon
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| New Moon Tuesday 28 |
First quarter Sunday 5 |
Full Moon Monday 13 |
Last quarter Monday 20 |
Click HERE to see the phase of the Moon on each day of the month.
Monthly Highlights
Although we are just starting to notice the days getting longer, there is still plenty of darkness around to allow us an early evening look at the night sky. If we are lucky, we may spot one of the following monthly highlights:
February 5th - Another chance to see a Mars-Moon conjunction
There will be another chance in early February to see the waxing (getting fuller) Moon passing very close to the planet Mars. If you look high above the southern horizon shortly after sunset on February 5th, you will see the Moon already fast approaching Mars. This will continue throughout the evening with the closest approach occuring over the western horizon around 10.30 pm, when the two objects will be within an outstretched fingers-width of each other.
© Stellarium
The purple line in the above image is known as the ecliptic and it traces out the path of the planets (apart from Pluto), the Moon and even the Sun through the stars. For those who have done a little physics or maths, it represents the rotation axis or plane of the Solar System. Even though we cannot physically see this ecliptic line, we know that the planets will never be far from it.
The Planets
Click HERE and start the Electric Orrery to see where all the planets are today in relation to each other.
MercuryMercury starts the month behind the Sun but within a week will be making an evening appearance shortly after the Sun goes down. By the end of the month the evening show will have stretched to nearly 60 minutes as Mercury moves toward maximum angular separation from the Sun. Unfortunately, because the innermost planet is always low when the Sun is about, Mercury is one of those objects that the Liverpool telescope cannot safely observe.
VenusVenus is currently overtaking us on the inside after passing inferior conjunction (i.e. between us and the Sun) on the 14th January. Early birds can spot the brightest planet at 6am toward the east-southeast around 90 minutes before sunrise. During the month Venus increases its angular separation from the Sun, getting brighter as it does. By March we should have a good 2 hours worth of Venus spotting before the Sun spoils the party. Why not use the electric orrery to watch how Venus has just passed between us (the Earth) and the Sun.
MarsMars remains prominent throughout the month but continues to diminish in size and brightness as Earth moves away. It can be found high above the southern horizon shortly after sunset and spends much of the night crossing the sky until it sets in the west-northwest around 2.20am. This moves back to 2am by the end of the month as we continue to move away. We can still observe Mars using the Liverpool telescope, but sadly it will be another 18 months before we get really detailed images again.
JupiterJupiter continues to increase in size and brightness as we gradually start to catch it up on our inside orbit or track. At the outset of the month Jupiter can be found rising in the east-southeast shortly before 2am but by sunrise it will occupy the region low above the southern horizon. Jupiter remains the second brightest planet (after Venus) and is currently the second best target to observe after Saturn - although this status will reverse come the summer. Why not use Go Observing to obtain an image of Jupiter and see if you can capture its elusive red spot.
SaturnSaturn is by far the best target to observe at the moment, after passing opposition (opposite side of the Earth to the Sun) on the 27th January. It rises in the east-northeast shortly after sunset and reaches high above the southern horizon just 30 minutes after midnight. Too late for most of you perhaps but not too late for the robotic Liverpool telescope. If you act fast in requesting an observation, you may end up bagging the best picture of the year. Hopefully any images should show weather features on the surface of the gas giant and even detailed structure in Saturn's ring systems.
Constellation of the monthEach month, new constellations are highlighted for you to identify in the night sky.This month we will be looking for the most famous pattern of stars visible from the UK, namely the constellation of Ursa Major, which is latin for Great Bear. Due to its well known shape, Ursa Major is also known by more familiar names such as the Plough in Britain and the Big Dipper or Saucepan in the USA.
 February Night Sky Ursa Major is important for another reason in that it provides a great way for astronomers to find the North or Pole Star, officially known as Polaris. We can conveniently use the two 'pointer' stars on the lower edge of Ursa Major in the above image to point roughly towards 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. However, we need to be a little careful in using the above skymap to find things in the sky. The reason being that the map is a picture of the whole night sky from the viewpoint of an observer. Think of the above picture as a half dome or hemisphere into which you put your head. If you turn the image so that you face the south point on the image and turn 90 degrees to the right you will then be looking west - just like in the real world. Turning another 90 degrees will have you facing toward the North Star and looking at the scene shown in the picture below.
 Looking for Ursa Major Remember that this picture is only for 8 o'clock on the evening of the 1st February 2006. Later in the evening Ursa Major will be shifed and rotated due to the Earth's own rotation. During a 24 hour period the constellation will rotate in a big circle around Polaris, although we will only see half this rotation during the night. The movement may not be noticeable over short timescales but if we look shortly after sunset and then again around 10pm, Ursa Major will have moved significantly. Mythology: Ursa Major Artemis, the moon goddess, was followed by a band of beautiful nymphs, all sworn to a vow of chastity. One of the most lovely of these was Callisto. She was spotted by Zeus, a god with a particular fondness for mortal women, on one of his many visits to earth. Disguising himself as Apollo, brother of Artemis, he overcame any scruples Callisto may have had and they became lovers. Eventually, Callisto was delivered of a son, and he was named Arcas (from the Greek arktos or "bear"). Knowing that Artemis would be furious with Callisto for breaking her vow, and more especially to shield her from the wrath of his wife, Zeus changed his unfortunate lover into a bear. She was forced into a lonely exile, roaming the forests and hiding from human hunters. Many years later, her now fully-grown son Arcas was hunting in the woods when he saw a great bear which was, in fact, his own mother. As he lifted his bow and arrow to shoot her, Zeus quickly intervened, and changed Arcas into a little bear so that he immediately recognised his mother. The story has a happy ending as, lonely no more, Callisto and her son were transported to the heavens, thereafter to be known as the Ursa Major and Ursa Minor.
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