Tardigrades go where the slime takes them

Is snail slime the secret to the water bear's dominance?

Tardigrades can lumber along surprisingly well for their size, but to move from habitat to habitat, they probably have to hitch a ride. DEPOSIT PHOTOS

Sorry, you can’t eat these popular foods on the International Space Station

Fizzy drinks, salt and pepper, and alcohol are some of the culinary items that don't make the safety cut for space travel.

NASA astronaut Anne McClain and David Saint-Jacques of the Canadian Space Agency personal-size pizzas with safety-approved toppings and fixings. NASA Johnson Space Center

The most precise atomic clocks ever are proving Einstein right—again

One of the atomic clocks can track time to within one second over 300 billion years.

An atomic clock at the National Institute of Standards and Technology's JILA. Jacobson/NIST