common occurance in some regions of
- Chinatown, San Francisco (Wikipedia)
The Chinatown centered on Grant Avenue and Stockton Street in San Francisco, California, (Chinese: 唐人街; pinyin: tángrénjiē; Jyutping: tong4 jan4 gaai1) is the oldest Chinatown in North America and one of the largest Chinese enclaves outside Asia. It is also the oldest and largest of the four notable Chinese enclaves within San Francisco. Since its establishment in the early 1850s, it has been important and influential in the history and culture of ethnic Chinese immigrants in North America. Chinatown is an enclave that has retained its own customs, languages, places of worship, social clubs, and identity.
- Polygonal patterned ground (Wikipedia)
Polygonal, patterned ground is quite common in some regions of Mars. It is commonly believed to be caused by the sublimation of ice from the ground. Sublimation is the direct change of solid ice to a gas. This is similar to what happens to dry ice on the Earth. Places on Mars that display polygonal ground may indicate where future colonists can find water ice. Low center polygons have been proposed as a marker for ground ice. Polygonal terrain is also found on earth’s permafrost.
