The Sun is the most spherical object ever observed.
Each of the Apollo moon rockets used five Rocketdyne F1 engines on their first stage. Each one remains today the largest and most powerful liquid rocket engines ever. When five were tested together for the first time in 1966, the United States national energy output increased by 5% for the two minutes that they were firing.
The energy density of a human hand is comparable to 1 liter of gasoline.
1 kilogram of water = 1 liter of water (at room temperature and sea-level pressure)
Jupiter and Saturn have more than 60 known moons each.
Pluto is not a planet, but a dwarf planet. It is estimated that there are probably 30 or more similarly sized dwarf-planets beyond the orbit of Neptune, but this has not been confirmed because they're so small and dim, and thus hard to find.
The worst aircraft accident ever was the Tenerife Airport Disaster in the Canary Islands in 1977. Nearly 600 people died because two fully loaded jumbo-jets collided on the runway. The cause of the accident was poor weather, human error and communication problems.
It is estimated that Norman Borlaug, an American biologist, has saved over a billion lives through his research in creating more robust varieties of wheat and grain that are resistant to disease, making it easier and cheaper to feed populations.
The same person (John Stapp) who invented the ejector seat also invented the crash-test dummy and the car safety belt. His research led him to discover more pilots were being killed in automobile accidents than faulty aircraft design.
The RMS Titanic had three propellers, but only two were capable of reversing because they were driven by expansion pistons. The middle propeller was driven by a one-directional turbine. 1999 movie Titanic accurately depicts this.
The largest known black hole, Holmberg 15A, is estimated to be over one light-month in radius. It's several thousand times the width of the entire solar system, and weighs as much as half of the Milky Way galaxy.