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We got back to the Island on Sunday morning after spending Christmas in Belfast and New Year in Ayrshire. Whilst we were in Scotland, the snow conditions in the Scottish Ski Areas meant it wasn’t worth making the trip up, but as a consequence we were able to finish the level 4 snowboarding at Xscape, and we’re both now able to hire snowboards and use the slope without an instructor!

It’s still dark getting home from work, so it’s unlikely I’ll be flying my Esky Belt-CP Radio Controlled Helicopter unless we get a nice weekend. I’ve had it since November and only flown it (well, skated around the floor), 5 times. 

However, a nice clear night last night let me try out one of my other Christmas presents. My parents got me the Celestron Skymaster 15×70 Binoculars for starwatching. I’ve been talking off and on about a telescope for the past year, but always get put off as I probably wouldn’t have the time to take it out, align it and so on. The binoculars are a great solution and last night I was able to see the Pleiades Cluster (M45) and Orion Nebula (M42). The latter especially was great as although it’s almost visible with the unaided eye, the nebula cloud is clearly visible through the binoculars.

But why is the post called “Back to work!” – I hate going back to work after Christmas without a holiday booked, and we had nothing booked for 2009. So, first day back I requested a holiday week at the end of February so we can go skiing, and by the end of the week the holiday should be booked! Anyway, as it stands, today I’ve got 37 work days till that comes around. That’s only 6 full Mon-Fri weeks!

International Space Station Visual Pass

That’s right folks, I’ve been playing at Astrophotography with my new Canon EOS 450D, and the past few days the International Space Station has been particularly bright. The image was recorded over a 20 second exposure, not ideal as the star trails are obvious, but for a first attempt I’m quite satisfied. Once I’ve worked out how to do multi-image align and stacking I’ll have a go at that.

The site Heavens Above is a good resource to find out when the ISS will be visible, as well as the fascinating Iridium satellite flares, which are apparently visible in daylight.

It’s odd standing there looking at the ISS cross the sky knowing that it’s travelling at over 17000 miles per hour, and is less than 500 miles away.

More of my beginners astro-images are in the Gallery but for some really great pictures look at Astropix.com

I’m still thinking about buying a telescope! At least it’s not so cold at the moment. If I can make it till October, that will be 10 months of thinking, and that’s usually a good sign that I won’t get bored too soon. It’ll be cold out again by then though…

I started looking at celestial navigation as a result of wanting to recreate a transatlantic flight in FlightSim without Inertial or GPS navigation systems. There is a simulated bubble sextant available for FS2004, and it works well but doesn’t give you that appreciation of the sky that the real process does. So, I thought it would be fun to try for real. The sextant stuff that is, not the transatlantic stuff…

Two problems: 1 – I don’t own a sextant. 2 – It’s really cold outside.

If you’ve not seen the package “Stellarium“, download it and install it now. It gives you a real time view of the sky, and is fantastic. So good in fact I’ve been considering buying a telescope. (In the summer though: Outside. Cold. Really.)

Stellarium also gives you a display of the Elevation (referred to as Height) of stars and planets. As that is essentially all a sextant does, one can do simulated star shots from any location on earth from the comfort of your living room. The skill of operating the sextant device is bypassed by this, but it does let you practice position fixing.

So all one needs now is a Nautical Almanac and Sight Reduction Tables to determine the expected Azimuth and Elevation for a known (assumed) position. Once the excitement of the Sight Reduction Tables has worn off, the US Naval Observatory has a facility to generate an almanac page for a time and assumed position. A map or piece of graph paper to plot the lines of position completes the navigation kit.

More information on the process can be found at celnav.de, including a comprehensive guide. Once you’ve got your position, you can learn how to navigate to your next waypoint thanks to Ed Williams Aviation Formulary.

I used an old 1:500000 VFR chart and set Stellarium to a random location. (Stellarium can’t set a random location, so one needs a glamourous assistant for this part!). Using the USNO table, I was able to get an accuracy of 1NM when over 45NM from the assumed position. That’s a result in my book!

All fascinating stuff, and I’ll probably buy a cheap sextant to give it a try – on the ground though – Distress & Diversion on 121.5 are a better bet if you’re really lost!

However, should you see someone standing outside on the Ben-My-Chree with a cheap sextant, a VFR chart and a Powerbook (and probably a puzzled look) don’t worry, the boat’s not lost!