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!

The Scale of the Solar System

Urban Astronomer avatarPosted on by

A view of the largest objects in the solar system (other than the Sun), to scale with each other, everything larger than 400 kilometers in diameter, except that there are only eight trans-Neptunian objects standing in for lots that probably are larger than that. Credit: © 2011 Emily Lakdawalla, the Planetary Society. Images from NASA / JPL & JHUAPL missions, processed by Bjorn Jonsson, Mattias Malmer, Ted Stryk, & Gordan Ugarkovic. TNO art by NASA, ESA, and A. Feild (STScI) … Continue reading →

Earth from Orbit – video

Urban Astronomer avatarPosted on by

If you point your browser to The Gateway to Astronaut Photography of Earth, you will find a complete collecton of images of Earth taken by astronauts in space.  James Drake is a science educator with a good eye for spectacular scientific imagery, and has made good use of that site.  He has stitched together 600 photographs of Earth taken from the International Space Station to create the timelapse video on the left.  The camera is set up for night-time photography, … Continue reading →

Comets

Urban Astronomer avatarPosted on by

Comets have always been special.  In ancient times, the sky was a stately ordered place, with the Sun, Moon, Stars and Planets all moving in their stately and predictable paths.  But every now and then, something strange and new would appear.  It would start as a fuzzy star with a misty trail behind it, growing from week to week until it formed a spectacular arc across the sky before fading away and vanishing.  This was not a part of the … Continue reading →

Vesta shape model – video

Urban Astronomer avatarPosted on by

The Dawn mission is equipped with cameras built and operated by the Deutsches Zentrum für Luft- und Raumfahrt  (DLR, or the German Aerospace Company), which are working overtime to collect as much data about Vesta, the second largest asteroid in the Solar System.  They have recently completed processing the footage received so far to build a shape map of the asteroid, which is a crucial tool to understand the morphology of Vesta. Vesta has a very complex shape – more … Continue reading →

Venus

Urban Astronomer avatarPosted on by

As one of the classical planets, Venus has been a familiar sight to humanity ever since we first started looking at the stars. Like Mercury, Venus’s movements are bound to the Sun but the similarities end there. Venus moves more slowly, and wanders further. It also shines extremely brightly – only the Sun and the Moon are brighter than Venus. Venus is easily identified as the Evening or Morning star and often passes near to the Moon, putting on a … Continue reading →