We published this article for the whole month of January 2018, but because the night sky is such a fascinating place with some many things going on, we thought we would provide a more detailed snapshot of the second week of January. There’s a couple of interesting events occurring including Mars and Jupiter getting very close to each other (they aren’t really getting close, it just looks that way from here) and the appearance of some old favourites on the Southern horizon. Of course for deep sky enthusiasts the Moon gets out of the way later in the week, rising later and later and not being so bright which means we can really start to appreciate the beautiful open clusters between Canis Major and Canis Minor.
One of the more interesting sights this week will actually occur a day before the week we are covering, but because we’re publishing this early we can safely talk about what is happening in the early hours of Sunday morning of the 7th. If you get up just before the Sun and train your eyes on Jupiter, which will be in the East in Libra, at just over three hand widths high, at about 35 degrees, you’ll see it very close to Mars. At 5:20am Mars will be about 15 minutes visually in angular distance from Jupiter. Physically they are still a good 600,000,000 km apart so you won’t have to worry about them knocking into each other and messing up the whole Solar System. What will be very cool though, is that with the right eyepiece in your telescope you might be able to see Jupiter, it’s four Galilean moons and Mars, all in the field of view at the same time. Europa and Io will be very close together so it might take a bit of effort to split those two.
Mars and Jupiter do get a bit closer, visually about 12 arc minutes apart, but that’s later in the day at around 10am when the Sun is well and truly up, though might not be visible in Wellington because it always seems to be cloudy lately. Now, since you’re already up, you’re going to be in a great position to see Mercury. The best time to view Mercury was last week but it’s still going to offer some good viewing, as it will be at 10 degrees above the horizon and directly East South East. It should be easy to spot as Mercury, is quite bright at -0.3 magnitude, but it’s also competing against the rising Sun so you won’t have long to look at it and you’ll want to make sure your telescopes and binoculars are well away from your eyes before the Sun gets up. If you have a very good horizon you might also get the chance to have a look at Saturn which is just starting to appear a little to the right of Mercury and below at about 5 degrees above the horizon. Obviously this close to the horizon the views are going to be marginal but for the sake of seeing the beautiful ringed planet, it’s definitely worth it.
Later in the week both Mercury and Saturn get visually quite close to each other in Sagittarius, about 52 minutes apart. Again, like Jupiter and Mars, you don’t have to worry about them colliding as they’re about 1.5 billion km from each other. Though, having them that visually close, offers the opportunity to compare the sizes. Saturn is so huge that even at the distance it is from Earth and Mercury, it is still visually 15.1 arcsecs in size, while Mercury is about a third of that at 5.5 arcsecs. They’re both going to be at their closest in the Southern sky on Sunday 14th January just before dawn, and still very low on the horizon before the sun gets up, so not the best observing conditions and the sky will be quite light by that stage, being only 40 minutes or so from sunrise. The below picture shows how they’d line up if the Solar System was viewed from above.
For observing everything else the excitement doesn’t end, Orion is very high in the sky so giving fantastic views of the rich collection of nebulae it has, including M42, M78, Running Man, the Flame Nebula and the visually elusive B33, Horse Head Nebula. At the bottom of Orion is Betelgeuse, which we covered in the December night sky review, and along to the right of Betelgeuse in a roughly straight line, about 25 degrees away, is Procyon in Canis Minor. It’s the eighth brightest star in the sky, and is reasonably close, at about 11 light years away. If you imagine a line going between Betelgeuse and Procyon then at just before the halfway point from Betelgeuse (about 40% of the way), there are a couple of very interesting objects. Above the imaginary line is the Rosette Nebula (NGC2239), which surrounds an open cluster. The cluster is very easy to see with binoculars, but if you want to spot the nebula you will need a telescope and a good dark sky. Below the imaginary line and slightly to the right is the Christmas Tree Cluster (NGC2264), the two objects are about 5 degrees apart. The Christmas Tree Cluster is easily visible through binoculars with loads of reasonably bright stars. At the upper end of the cluster is the Cone Nebula, which, unsurprisingly, looks like a cone. With a really dark sky and and a large aperture telescope you might get a faint glimpse of this nebula.
Above Procyon at about 65 degrees above the horizon in the North East direction is Sirius, the brightest star in the sky and it’s in Canis Major. In that general patch of the sky there’s a lovely collection of open clusters that made it to Charles Messier’s Not a Comet List. These are: M48 (down near Canis Minor), M46, M47, M50, M41 and M93. You can do your very own Minor Messier Marathon (MMM), without having to move the telescope or binoculars very much. In fact, you can add two more open clusters of your MMM by dropping back down to Procyon, then finding a patch of sky about half way between Procyon and the horizon and a little to the right where you should spot the Beehive Cluster (M44) which is basically in the middle of the Cancer constellation. To complete the set of Messier open clusters, head to the right and up from M44 to the next brightest star, about 8 degrees away, which should be Acubens. Just a degree or two above and to the left is M67, which is full of a bunch of stars very much like our own sun.
The finale for the week is the appearance of some of my favourite objects. They’re not in the best spot for viewing, being so close to the horizon, but if you can stay up until about 2am then you’re in for a treat. The first object is the huge and bright Omega Centauri globular cluster, this thing is a monster and we’ve written a bit about here. At Milky-Way.kiwi we have a bit of a debate between which is better, Omega Centauri or 47 Tucanae, I like Omega Centauri the most so I’ve included the picture I took of it a few years ago:
Finding it is really easy because it is so huge and because it is visible to the naked eye and amazing in a telescope due to its size, because it has about 10 times as many stars as a typical globular cluster. It can be found by looking about 13 degrees left of the Pointers and will appear as a big fluffy star to the naked eye. The other awesome sight which is well worth a view is M83, which is a huge spiral galaxy also known as the Southern Pinwheel, it is fantastic in a telescope. I have viewed it in 16″ reflector and it is a sight to behold, I think that it is the best galaxy in the sky to visually observe. We’ll talk about M83 in future posts, when it’s a bit higher in the sky, where it can be truly appreciated. M83 is about halfway between Omega Centauri and the star Spica.
That’s the sky for next week, enjoy!