With the Australian Solar eclipse coming in 2028, it’s time to get familiar with solar telescopes. With Lunt telescopes you can see the surface of the Sun using white light, or Hydrogen alpha and Calcium-K filters. These all show different aspects of what’s happening there. If you want to photograph it as well, there are cameras for that too.

Mars opposition is in mid-January next year. But before that happens, Mars is going to enter retrograde motion, where it stops being overtaken by the background stars and starts overtaking them back. Retrograde motion stumped the ancient astronomers and had a hand in stimulating the rise of modern scientific thought.

Inspired by a video of an eclipse of Phobos, Bill wondered about the definitions of moons, planets and asteroids. Why are potato shapes important, and how did Phobos stop being one and start being another?

Bill used the Benro Polaris tracking mount to get images of comet Tsuchinshan-ATLAS. This post tells the story of the expedition. He also reviews the Polaris.

How do we tell the time on the Moon? This will be an important issue once humans establish a long-term presence there. We list a few of the problems with time, and how they’ll probably agree on a single Coordinated Lunar Time.

The Lunar X is a pattern of light cast by the rising Sun over a complex group of walls near the Werner crater. It’s only visible for about 45 minutes each lunar cycle and it’s only visible a couple of times each year to people on Earth. We knew of an apparition coming up, so we used a remote dome to get an image. We did have to battle our share of clouds, of course.