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!
Summer, Autumn, Winter and Spring. The cycle of the seasons has been known since the dawn of time and human beings all over the world use them to mark moments in their personal histories. Some people are astonished to learn that the seasons are six months out of phase on opposite sides of the globe, something which amuses us in the Southern hemisphere no end. But what actually causes seasons? Many people are dimly aware that the Earth’s … Continue reading →
According to the caption on this video, the two witnesses were standing on the promenade of Armon Hantziv in Jerusalem when they saw a bright light in the sky at about 01h00 in the morning. They started filming and were in time to capture the light descending rapidly to hover very close to the ground, directly over the Dome of the Rock in the Jerusalem old city, a site of religious importance. After hovering for a while, the light then … Continue reading →
There are five planets which are visible to the naked eye. They move through the sky, from week to week, so you need to know where to look if you want to see them. The good news is that the movements of all the planets are limited to a narrow strip of sky called the ecliptic, along with the signs of the zodiac, which is halfway between the north and south poles. This means that, unless you’re in the arctic … Continue reading →
On 19 June 1976, the first of the two Viking probes reached Mars orbit, and began the first phase of its mission: photograph the surface of Mars so that the engineers back in the JPL lab on Earth could find a suitable landing spot (The entire set of images returned by the probes can be ordered on CDROM from NASA, incidentally). On 25 July, the image to the left arrived. It was of an area known as Cydonia, and showed … Continue reading →
As hinted in an earlier article, Astronomers consider Light Pollution to be the number one threat to civilization, trumping global warming, terrorism and reality TV. Perhaps our priorities are a little skewed, but there is increasing evidence that light pollution affects all of us, whether or not we care about seeing the stars. History It is definitely a new problem. Before the advent of electricity, everybody who looked up at night saw the sort of breathtaking stellar vista that always … Continue reading →
