In space, astronauts cannot cry properly, because there is no gravity, so the tears can't flow down their faces!
175
Saturn's rings are about 500,000 miles in circumference but only about a foot thick.
160
The volume of the Earth's moon is the same as the volume of the Pacific Ocean.
178
The Space Shuttle main engine weighs 1/7th as much as a train engine but delivers as much horsepower as 39 locomotives.
147
The population of the Earth has more than doubled since 1950.
151
The Earth weighs around 6,600,000,000,000,000,000,000 tons (5,940 billion billion metric tons)!
221
There are approximately 3,500 astronomers in the U.S. - but over 15,000 astrologers.
124
An unprotected human can survive up to 1.5 minutes in space with no permanent bodily damage.
82