Author Archives: Allen Versfeld

About Allen Versfeld

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!

Phases of the Moon

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Everybody knows that the Moon changes its face.  Sometimes we have Full Moons, other times it’s a Half-moon, or a crescent, or there’s no Moon at all.  And everybody knows that these are called the phases of the Moon.  But not everybody knows that these faces follow a regular cycle, or that the common descriptions are misleading at best.  A proper understanding of what’s actually happening to make the moon show different faces, and the nature of the “Dark Side … Continue reading →

NanoSail-D might not be dead

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Artist concept of Nanosail-D. Is it alive? Credit: NASA Early in December last year, NASA’s experimental FASTSAT (Fast Affordable Science and Technology Satellite) microsatellite was launched into orbit from a private facility on Kodiak island in Alaska.  FASTSAT is built as a research platform, and has the ability to launch smaller nanosatellites.  One of these was NanoSail-D, intended to study the design and operation of solar sails in orbit and on 6 December, mission controllers triggered it’s ejection into space.  Although data … Continue reading →

This is going to take longer than I thought

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“Why”, you ask?  Well this week I formally began work on this semester’s studies.  I’ve brutally cut down the time given over to study, but this still means that 4 days of the week are fully scheduled from breakfast to bedtime.  Every second Saturday, I’ll go to the class, leaving only Friday evenings and Sundays as possible times to work.  Now consider that I have a family who need my time and attention. . .  Still, I should be able … Continue reading →

There was no list!

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A little while back, I reported on a discussion between NASA and hollywood movie execs in which they discussed ways to promote science within films.  As part of those discussions, a list of movies was released which showed the ten best and worst science fiction films for realistic protrayal of science.  This seems to have irritated some of the people who were actually present at the meeting.  They argue that the original report was totally bogus, that quotes were fabricated by the reporter … Continue reading →

16 January 2011

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I missed the class yesterday, but that’s a consequence of having small children, studies, and an astronomy webpage that needs updating!  Still, grinding continues at home in the garage and progress gets made.  Today I ground for about 90 minutes (still with the #80 grit), using slightly longer diametral strokes.  After drying the mirror, I measured the depth with the feeler gauge and straight edge (0.63mm – up from previous session).  On a whim, I measured the diamter as well and … Continue reading →