An airplane casts a shadow over Lake Natron in Tanzania. The lake's color comes from a red pigment in cyanobacteria, which feed on high levels of salt in the lake.
Photograph by George Steinmetz
Water ripples over sand in the Virgin Islands.
Photograph by Todd Gipstein
意译:海浪在沙滩上面泛起涟漪,处女岛。
A snowflake's shape depends on the temperature at which it forms. This type of snowflake, called a sectored plate, forms when the temperate dips below about 5 degrees Fahrenheit (-15 degrees Celsius).
Photograph by Kenneth Libbrecht