An earth-sized hole in Jupiter...

... discovered by an amateur, Anthony Wesley, a 44-year-old Australian, who wrote on line:

I came back to the scope at about 12:40am I noticed a dark spot rotating into view in Jupiters south polar region started to get curious. When first seen close to the limb (and in poor conditions) it was only a vaguely dark spot, I thought likely to be just a normal dark polar storm. However as it rotated further into view, and the conditions improved I suddenly realised that it wasn’t just dark, it was black in all channels, meaning it was truly a black spot....

It took another 15 minutes to really believe that I was seeing something new - I’d imaged that exact region only 2 days earlier and checking back to that image showed no sign of any anomalous black spot.

Now I was caught between a rock and a hard place - I wanted to keep imaging but also I was aware of the importance of alerting others to this possible new event. Could it actually be an impact mark on Jupiter? I had no real idea, and the odds on that happening were so small as to be laughable, but I was really struggling to see any other possibility given the location of the mark. If it really was an impact mark then I had to start telling people, and quickly....