This winter has seen a succession of storms batter the UK and clear skies have been few and far between. I managed to grab a couple of hours observing the other day and took enough pictures to compose a couple of images.
The first is Comet Catalina.
Through the eyepiece of the 80mm refractor the comet looks like an elongated fuzzy patch of light. The camera picks up the dust tail a little better. Catalina is moving away from both the Earth and Sun now and it will fade substantially in the coming weeks.
The second is Orion's Sword - a region below the Belt stars which contains the Orion Nebula.
This one was taken with a modified Nikon D90 (making it easier to pick up the red light of hydrogen emission).
A line of bright planets has formed in the morning sky but the weather is back to normal service of rain and wind.
Take a look at this simulated scene from the morning of January 27th 2016 at around 7am.
The view is south facing at around 7am. There are five planets scattered across the morning sky (six, if you include the one you're standing on!)
If you're in the UK then you'll have from about January 24th - February 8th to see all five planets.
The positions of the planets will be slightly different each successive morning; for example, Jupiter is apparently moving west (away from the Sun) whilst Venus is moving towards the Sun. These apparent motions are caused by our own vantage point on a moving planet as well as the real movement of the planets around the Sun.
Mercury will be the trickiest planet to see. Fortunately it is not far from Venus, the brightest planet: just look to the left of Venus and a little lower towards the horizon. You'll need a clear view of the horizon and any wisps of cloud may be enough to hide Mercury in a twilight sky. If you have binoculars then it should be easy to see Mercury.
The moon, which is visible in the picture above may help to identify the planets on various mornings over the next couple of weeks.
After the first week of February it will become very difficult to pick Mercury out of the morning twilight (from the UK at least). Venus is also drawing closer to the glare of the Sun. The other planets - Saturn, Mars and Jupiter - will continue to be visible in the coming months.
Although the planets look like they're in some kind of special alignment - that's not really the case. The planets always fall close to a line in the sky called the ecliptic and that's a consequence of the fact that the solar system is disk shaped, with the planets orbiting more or less level with each other (and the Earth).
What makes this configuration more notable is that the planets are all on the same side of Sun from our persepctive. Imagine if the Sun were somewhere between Saturn and Mars in the picture above; it would mean Mars and Jupiter (to the right) would be visible in the morning sky, whilst Saturn, Venus and Mercury (to the left) were in the evening sky. That's a more typical situation.
When viewed from above the solar system you can see the arrangement of planets isn't really a notable alignment.
The Earth's orbit is highlighted in red. The other planets are spread out in different positions along their orbits. If you draw a line from Jupiter - Earth - Mercury the angle at the Earth is around 110 degrees. For all the planets to be visible in the sky at the same time we just need that angle to be less than 180 degrees with the Sun outside of the line (to the left or right of the first or last planet respectively).
Seeing a line of planets like this is fairly rare! The last event like this occurred in the evening sky in the Spring of 2002.
Comet Catalina is currently well placed for UK observers wishing to see it. The comet is tracking north in the sky and over the next week it will bypass the familiar seven stars of The Plough.
An interesting photographic opportunity occurs on the night of January 16th (going into the early hours of the 17th) when the comet will be close to the celebrated double star Mizar (and Alcor) and a bright-ish galaxy called M101 (the Pinwheel).
The picture above is a Stellarium rendition of Mizar, Comet Catalina and the Pinwheel Galaxy. This is the late evening of January 16th. But given that the moon is above the horizon until just after midnight, best views (and pictures) will be obtained during the early hours of the 17th. This is a wide field of view, so I'll try to capture this with the Nikon D80 mounted directly onto my HEQ5 Pro mount; I think shooting at 200mm will frame the region nicely!
Venus has been a morning sky object for months. Saturn has been hidden behind the Sun until recently and has joined Venus in the sky before sunrise. They're moving across the sky a somewhat different speeds and in the second week of January the two planets pass each other.
For a few hours on the morning of January 9th the two planets will be separated by gap just 1/5th of the diameter of the moon. Unless your eyesight is fairly bad, they will still appear as two distinct points of light but it's still rare to see bright planets so close together.
Venus is much the brighter of the two planets; although smaller than Saturn it is much nearer to us and shrouded by highly reflective clouds.
Here is the simulated view through my 8-inch Meade LX10 with a 5mm eyepiece at around 6.30am.
Venus and Saturn look roughly the same size (the disk of Saturn, without the rings). Without any depth perception it might help if you know that the actual size of Saturn is nearly 10 times larger than Venus. Therefore, for them to look the same size, Saturn must be about 10 times further from us than Venus.
There are a number of other planetary conjunctions in 2016 - most will happen in the last quarter of the year.
Whilst not spectacular, Comet 2013 US10 Catalina remains an easy binocular object for UK astronomers. It began the year close to Arcturus and there a lots of great photos of that alignment at spaceweather.com. During January the comet continues to track north eventually passing The Plough and getting within ten degrees of the north celestial pole (and Polaris)
Comet Catalina should be visible with binoculars for the entire month. It is fading: the magnitude drops from +6 to +7 by the start of February. The comet is nearest to Earth on January 17th.
The best time to view Catalina is in the morning sky from about 3.30am until dawn breaks until around January 20th/21st. After that, the comet is so far north that it becomes circumpolar and never sets over the UK. But the optimum time to view Catalina during the last week of the month will be during the evening after the moon has set.
Dr Adrian Jannetta
Guitar strummin' explorer of the universe. Mild mannered maths teacher by day and astronomer by night.