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!
Tonight at 11:27pm, South African time, you need to step outside and look upwards. Bring a camera. As an Urban Astronomer reader, you already know that the Cassini robotic spacecraft will pause in its mission to study Saturn and it’s moons to look back home and take a photograph of Earth. The camera’s shutter will be held open for 15 minutes (at a billion kilometers distance, Earth is a surprisingly dim dot) so you’ve got that long to take part … Continue reading →
As of February 2024, we know of sixteen moons orbiting Neptune. The largest, Triton, was discovered only 17 days after Neptune itself was found in 1846 and it would be over a hundred years before any others were first seen. Triton is one of the larger moons in the Solar System with a diameter of 2700km, and orbits backwards around Neptune. The most recently discovered moon, by contrast, is less than 8 km across. No doubt there are more … Continue reading →
Astronomers have assumed for some time that our Sun has a tail, formed from material ejected in the solar wind, and shaped by the Solar System’s passage through the interstellar medium (ISM). Repeated announcements from NASA about the Voyager spacecraft’s passage from the Solar System through to interstellar space are really stories about how they’re passing through the surface of that tail. But new data from NASA’s Interstellar Boundary Explorer (IBEX) have given us our first clear view of what … Continue reading →
In case you missed the earlier announcement, ScopeX (South Africa’s top astronomy and telescope exhibition) will begin it’s 12th run on 20 July, and runs for the entire day at the military history museum in Johannesburg. This update just came in from Eridanus Optics, one of the commercial sponsors of the expo. For the record, I have no link with the company, and have never even been a customer, but I did meet Andrie at the 2010 ASSA symposium, and … Continue reading →
This years ScopeX telesope and astronomy expo is fast approaching, and if you’re anywhere near Johannesburg, South Africa on 20 July, I’d strongly recommend you join us there. This year they have a full line-up of speakers, including repeats of some of the more popular presentations from last year’s ASSA symposium. A full program of talks can be found at the official ScopeX website. There will also be demonstrations of rocketry and telescope making, science shows by Experilab, and a … Continue reading →
