Why do you bet on axions or WIMPs?
If you find dark matter, what are the next steps?
Will we need a whole new "Dark Standard Model"?
What's it like searching for something you may never find?
Galaxies might not have such discreet boundaries as we imagined. Instead, they might stretch out to great distances, forming a vast, interconnected sea of stars.
The biggest sunspot region in more than two decades produced many impressive solar flares. Just before it disappeared, it also gave us this beautiful display of coronal loops.
It looks like an artist's illustration, but it's a real image and it lets us glimpse the process by which planets are born in orbit around their stars.