For users of Mike Challis' space-weather page, you need to modify two of the scripts for changes of image types from services.swpc.noaa.gov for aurora images.
In image-space-aurora.php script change $ImageURL = 'http://services.swpc.noaa.gov/images/animations/ovation-north/latest.png';
to $ImageURL = 'http://services.swpc.noaa.gov/images/animations/ovation-north/latest.jpg';
and in
image-space-aurora-s.php script change $ImageURL = 'http://services.swpc.noaa.gov/images/animations/ovation-south/latest.png';
to $ImageURL = 'http://services.swpc.noaa.gov/images/animations/ovation-south/latest.jpg';
The source website has changed from PNG to JPG images for those two images.