January 2010 is a great time of year to find Mars in the night sky. Each evening it rises about 7.30 and it is easily identified with a very red glow in the sky. The main thing is where to look. Over the next few weeks it gets closer and closer and makes for easy viewing.

Viewing Mars

January and Feburary are the best months to observe Mars for a couple of years as the Earth passes between Mars and the Sun on January 29th(called opposition. Mars will be due south around midnight so highest in the sky. Oppositions of Mars occur at intervals of approximatly 780 days but, because Mars has an eccentirc orbit (as has the Earth to a lesser extent) the distance of Mars at opposition varies widely. If Mars is at its closest point to the Sun (at perihelion) and the Earth at its most distant point from the Sun, the distance between the two will be at its smallest and so Mars will have its greatest angular size. This happened two apparitions ago when Mars was at its closest for ~ 60,000 years and had an angular size of 25 arc seconds. At the opposite extreme when Mars is at aphelion, the angular size only reaches ~14 arc seconds and, sadly, this is the case this year. Closest approach is on 27th Jan at a distance of nearly 100 million kilometres when its magnitude will be -1.3. Very nicely, it then lies in the constellation of Cancer just above the Beehive Cluster. The Moon, near full will be in attendance to as shown in the chart which shows its motion westwards across the sky over the next few weeks. The fact that its angular size is not as big as it can sometimes be is partly compensated for by the fact that it reaches an elevation of around 60 degrees, so the atmosphere will not impede our view as much as when it is lower in elevation.

Why Earth and Mars are so close

To see significant detail on the surface requires a telescope of 4 inches or more. As the north pole is tilted towards us, we should be able to easily spot the, brilliant white, north polar cap. A slight pity for those with small telescopes is that the most prominent dark feature, Syrtis Major, passes behind the limb in the early evening, so will not be best seen. As Mars’s day is similar in length to ours, we will see a similar face at a given time over quite a long period. The free Planetarium program “Stellarium” will show you what could be seen at any given time of the night during the apparition.

Jan 1, 2010

Mars shines at mag -0.77 in constellation Leo with an apparent diameter of 12.67″. Distance from Earth is 0.73885 AU (111 million km).

Jan 9, 2010

Mars leaves constellation Leo and enters Cancer again, during retrograde opposition loop.

Jan 11, 2010

Apparent brightness of Mars exceeds -1.0 mag.

Jan 27, 2010

Closest approach of Mars and Earth (0.664 AU = 99.33 million km). Apparent diameter of Mars is 14.105″.

Jan 29, 2010

Mars opposition on Earth, Earth in inferior conjunction on Mars. Apparent brightness of Mars reaches -1.28 mag in constellation Cancer.

Elliptical Orbit

That change in distance is about 5 million kilometers, and is a small fraction of our distance from the Sun, so it doesn’t change the Earth’s temperature very much: a few degrees Celsius, but that’s about it. This is NOT the cause of our seasons….

The only reason I mention this is that is FREEZING here in Dublin, and it feels sort of ironic that we are as close as we get to the Sun. Yes I know about tilt and how it causes seasons….Its just cold right now! So I am off for a hot whiskey. Let me know if the sun appears a bit bigger, just don’t use a your new telescope to check Oh, and give  a thought to just how hot the Sun is. It is heating up a planet 93Million miles away….

Our Sun...

A Galileoscope at Christmas

Please note: The Galileoscope is NOT a solar telescope and should NEVER BE POINTED AT THE SUN!

1. Use the online assembly instructions from the web as they are better than the ones in the box. It can be quite tricky to get the eyepiece lens the right way around so pay careful attention to their orientation.

2. There are two eye pieces which can be assembled, the primary 2omm eye piece which gives 25x magnification and a “Barlow” eye piece which effectively doubles the magnification to a 50x magnification. It is very difficult to see objects using the barlow lens you have a very small line of sight, so my advice is to NOT use the Barlow lens. You might even find that you cannot see anything at all or think you assembled the eyepiece incorrectly. So skip step 22 in the instructions.

3. The way to focus the telescope is to slide the back of the telescope into or away from the body of the main telescope. Its not a very accurate process so if you are trying to focus, using the moon is a good method.

4. The telescope is designed for you to be able to use any standard 1.25″ eyepiece. Since I have one already, I replaced the galileoscop 20mm eyepiece with a 26mm eyepiece and it was much easier to see through. The image was clearer and more comfortable to see through. Price for a single eyepiece is about 30Euro.5. The telescope is equipped with a fitting to allow it to attach to a standard tripod. The heavier the tripod the better, but its more the height that you should be looking at. Since you are looking directly through the scope, anything high in the sky will require you to do a lot of bending down. Tripods are cheap starting at anything from 20Euro. Just keep in mind that while you connect to a nut in the telescope it is easy to rip off the telescope if you lean on one end. It happened within 20minutes of my 5year old son being near it. Easily repaired in my case. You can purchase a 90 degree “Erecting Prism”  which will making viewing a little more comfortable.  You should use something similar to the one below which slots into a 1.25″ slot. You can find them on amazon for approx 30Euro.

90 degree erecting prism

6. A Galileoscope is a refractor, this means that images are inverted, this is usually not a problem until you try to do two things. The first is trying to find something on the Moon. You must take into account that what you see through the telescope is an inversion of what you usually see with your own eyes, and what is shown on most maps.  looking at the moon and find anything on it (your standard map is not inverted), and secondly when you try to figure out which of the moon of Jupiter is which. The view through the eyepiece is upside down and right and left are reversed.

7. Don’t forget that there are optics activities also posted on the galileoscope website which look like a bit of fun. There is a full page of downloads to explore.

I’ll start posting on things to see with your new telescope over the next few days. Just remember that there is lots of light pollution in cities, so while you may hear about seeing details in Orion, or possibly the polar caps of Mars, try to be realistic. The telescope in ideal situations may be able to do this, but you have to keep your expectations grounded depending on where you are viewing from. I live in a city, so until I head off to the countryside I won’t see a huge amount of nebula detail. The great thing is that the telescope is so small and light, you can take it anywhere! You can also take pictures of the moon using your telescope, but you need the right attachments. I’ll cover that topic when I find out where to get them and how easy they are to use.

I suggest you start by downloading stellarium a superb method for navigating your way around the sky. Here is an image of tonight’s sky, where you can see Mars, Saturn just rising, and the constellation of Orion.

Our Place in the Cosmos - Credit Symphony of Science

Whow! You have to watch this video. Symphony of Science produced an awe inspiring 4 minutes of images and words featuring Carl Sagan among others. “Our place in the Cosmos” is just wonderful.

Thanks to Justin for sending on the link!

Enjoy.