Let's take a closer look at the inline filament diameter sensor - available for DIY now! Become smarter in 5 minutes by signing up for free today: http://cen.yt/mbthomassanladerer - Thanks to Morning Brew for sponsoring today’s video. Download the design and all files (Fusion source files, Eagle PC...
APOD October 22, 2023: Ghost Aurora over Canada
What does this aurora look like to you? While braving the cold to watch the skies above northern Canada early one morning in 2013, a most unusual aurora appeared. The aurora definitely appeared to be shaped like something, but what? Two ghostly possibilities recorded by the astrophotographer were "witch" and "goddess of dawn", but please feel free to suggest your own Halloween-enhanced impressions. Regardless of fantastical pareidolic interpretations, the pictured aurora had a typical green color and was surely caused by the scientifically commonplace action of high-energy particles from space interacting with oxygen in Earth's upper atmosphere. In the image foreground, at the bottom, is a frozen Alexandra Falls, while evergreen trees cross the middle.