Mysteries of Space! (links)
There is a mysterious giant hexagonal formation at Saturn's north pole. Nobody knows why.
The Curiosity rover came across something on Mars that sure looks like a hunk of processed metal, and it doesn't match up with any of the space junk we've left there.
Here's a video of the sun doing a rare hat-trick - solar flare, coronal mass ejection, and "coronal rain" all occurring at the same time. Watch for the point in the video where the size of the Earth is shown for comparison.