10,000 Meters. The hadal zone or trench zone is 20,000 feet deep and below the ocean floor.
More Science Trivia
Lunar Eclipse. A lunar eclipse may be total, partial or penumbral.
Greenhouse Effect. Venus and Mars also have a "greenhouse effect".
Pluto. Pluto and it's moon Charon are close in size.
Venus. The atmosphere of Venus is 95% carbon dioxide.
Gallon. A gallon is 128 ounces.
Contrail. High-flying jets produce ice-crystal clouds called "contrails" when they fly through moist, frigid air.