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!

New Australian Radio Telescope

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A new radio telescope in Western Australia’s remote outback promises to save the world billions of dollars by providing early warning of solar storms.  The Murchison Widefield Array (MWA) radio telescope, built as a Square Kilometer Array precursor project and unveiled late last year, has stared monitoring the Sun just in time for the current solar maximum.  Severe storms can damage power transmission systems and destroy the delicate electronics in expensive satellites if their operators aren’t given enough time to … Continue reading →

Can mirrors ‘catch’ lightning?

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Dear Urban Astronomer  Talking about the thunder storm in Pretoria last night, a co-worker of mine mentioned that she covered all the mirrors in her house because they can “catch and reflect” lightning… She said that lightning can behave like light and be reflected. I argued that lightning is not light, but a raw, electrical charge… I have never heard of this practice, and although it sounds like superstition to me, I was wondering if there is any truth in … Continue reading →

Let’s try this again

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29 months after I first put grit to glass, I’ve put my mirror on the test stand for the first time.  It’s not as good as I’d hoped. To recap: I last touched this project 10 months ago.  Since then, the mirror and the polishing lap have been sealed into plastic containers, and left to rot in the loft while life overwhelmed me.  But today, I got in my car and hauled everything down to Joburg and the ATM class. … Continue reading →

What is a Nebula?

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“Nebula” is the Latin word for cloud.  It was originally used to describe anything in the night sky that had a cloudy or diffuse appearance, and that wasn’t a comet.  Early in the 20th Century, however, it was discovered that some of these nebulae were actually “island universes” (galaxies or globular clusters).  Since then, the word refers to specific types of objects: Planetary nebulae are usually spherical and are the expanding shells of material ejected from dying stars.  They get … Continue reading →

Eta Aquarids

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Meteor showers have their origins in comets, and the eta Aquarids come from the most famous of all:  Halley’s Comet.  Every time it swings past the Sun, the comet heats up and sprays particles of dust out along its orbit and twice a year the Earth blunders straight into the debris streem.  When these bits of grit hit the atmosphere, they flare briefly before burning up and we see a meteor.  The first time we pass through the stream each … Continue reading →