Astronauts cannot belch - there is no gravity to separate liquid from gas in their stomachs.

10 percent of all human beings ever born are alive at this very moment.

Christian Barnard performed the first heart transplant in 1967 - the patient lived for 18 days.

Without its lining of mucus your stomach would digest itself.

It would take over an hour for a heavy object to sink 6.7 miles down to the deepest part of the ocean.

If our Sun were just inch in diameter, the nearest star would be 445 miles away.

The grey whale migrates 12,500 miles from the Artic to Mexico and back every year.

Quasars are the most distant objects in the Universe.