Allen is an amateur astronomer, an IT professional, a podcaster, a father of five growing kids, a barely competent chess player, and the owner and publisher of the Urban Astronomer podcast and website. He has formerly served as Director of the Astrophotography and Citizen Science sections of the Astronomical Society of South Africa. You can find his personal social media feed on Mastodon!
Re-beveled the glass, doing it properly this time. 100 grit waterproof paper, sprayed the glass down with soapy water, positioned it just hanging over the edge of my bench, and worked for 45 minutes. End result: proper bevel about 1.5mm wide, at a nice 45 degree angle. This should last a little longer. Used a lot less sandpaper than the previous attempt too. Since the rest of the family had an early night, I had time to kill, so did a … Continue reading →
I wasn’t expecting this, but the volunteers at the class expect me to continue working on my mirror at home! So after the class, I went on a shopping trip for a few essentials (a bucket, a plastic tray, sponges, spray bottle, that sort of thing). Monday evening I wrapped some 120 grit sandpaper around a block and put a 1mm bevel on both mirror and tool. Took about half an hour. Perhaps using a stone would have been quicker, but Johan … Continue reading →
Scientists at NASA’s Goddard Institute for Space Studies (GISS) released figures yesterday showing that 2010 tied with 2005 as the hottest year on record since 1880. This is despite the unusually cold temperatures across Europe and strong La Nina phenomenon. The place of next hottest year is a tie between 1998, 2002, 2003, 2006 and 2007. The global average temperature has been rising at an average rate of 0.20°C per decade. GISS collect weather data from more than 1000 meteorological … Continue reading →
The Sloan Digital Sky Survey (SDSS) is a fascinating attempt to map the entire sky at unprecedented levels of details, using digital cameras on large telescopes. The data collected in the various projects making up SDSS are of enormous value to astronomers, as they can be mined for experimental data, or used as a reference to compare against recent images. Probably the most well known user of SDSS data is Zooniverse, who gave us the citizen science project Galaxy Zoo. The third … Continue reading →
The Urban Astronomer has decided to start building his own telescope. This weekend, I began work grinding the primary mirror of what will (hopefully) become a six inch f/8 newtonian telescope on a dobsonian mounting – not too ambitious, but a perfect beginners project. I’ve set up a blog on this page where I’ll be keeping a diary of my progress, which you can follow by clicking here, or selecting ‘Making Telescopes’ on the left hand sidebar. The most recent … Continue reading →
