twins

Imagine the look on biologist Gerhard Scholtz's face when he looked down at this crab in New Zealand's Hoteo river, only to find three eyes looking back at him. Was this the result of a freak nuclear accident? An alien invasion? A mean trick? Nope. It's just Blinky.

The Amarinus lacustris crab, Scholtz would later conclude in an academic paper, is actually two crabs—conjoined twins.

Twins are always interesting (at least to those of us who are not a twin ourselves) and probably one of the few things more interesting than twins on Earth is twins in space! Mark and Scott Kelly, astronaut twins that have inhabited the ISS at the same time, are once more going to be contributing to NASA's science mission, but this time, one twin will be headed up to the ISS for a year and one will be left here on Earth!