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!

MAVEN mission to study martian atmosphere

Urban Astronomer avatarPosted on by

Over the past ten years, the various robotic rovers crawling across the surface of Mars have confirmed one fact beyond any doubt: A long time ago, Mars was a warm, wet planet with a thick atmosphere that could easily have supported life.  Yet today it is a frozen, barren, dry world with an atmosphere so thin that the any human explorers will need to wear pressurised space suits. So where did all the air go?  NASA’s new MAVEN mission was … Continue reading →

The beginning of a new era

Urban Astronomer avatarPosted on by

It’s been a few months since I migrated Urban Astronomer away from Google’s free hosting service and onto my own dedicated server.  I think it’s gone well, but it’s only today that I discovered the blogging feature and turned it on.  So this is my first entry. A few weeks ago, I realised that the current content model for UA just isn’t good enough.  I write a handful of info/educational articles about planets and stars and galaxies, but the bulk … Continue reading →

What the Milky Way looked like billions of years ago

Urban Astronomer avatarPosted on by

Astronomers working with the Hubble Space Telescope have studied hundreds of thousands of galaxies, to improve their understanding of how galaxies are born and change over time. These new results have allowed them to construct a model of what the Milky Way would have looked like shortly after it was first formed, between seven and 11 billion years ago.A team of astronomers led by Pieter G. van Dokkum of Yale University and Shannon Patel of Leiden University has shed light … Continue reading →

The day Earth waved at Saturn

Urban Astronomer avatarPosted on by

Last year in July, the Cassini spacecraft was briefly positioned so that it was in the orbit of Saturn, allowing it to point its cameras in the direction of the Sun and capture an ethereally beautiful image of Saturn’s backlit rings. Mission controllers knew that the Earth would be in the field of view of Cassini’s imaging systems, and publicised the event by comparing it to Voyager’s famous Pale Blue Dot image. Campaigners spread the word that as many people … Continue reading →

Frontier Fields program unites space telescopes to peer deeper into space than ever before

Urban Astronomer avatarPosted on by

In an ambitious effort to look further out into the universe than anybody has ever seen before, NASA will be combining the efforts of its three flagship space telescopes (The Hubble Space Telescope, the Chandra X-ray observatory and the infrared Spitzer Space Telescope) in a new program called Frontier Fields. Together they will use the gravitational fields of distant galaxy clusters to magnify the light from distant objects that would normally be a hundred times too faint to be seen … Continue reading →