The black diamond known as the "Enigma" will soon be sold at auction, but experts are unsure about the origins of the stunning gem.
Missing enzymes may cause troublesome knots to appear in DNA.
The hypothetical timepiece known as the Doomsday Clock stands at 100 seconds to midnight — the time that was set in 2020, marking humanity's lack of progress in making the world safer from global threats.
Black holes have been seen doing this before, but never in a galaxy so small.