common occurance in some regions of
- Warp and weft (Wikipedia)
In the manufacture of cloth, warp and weft are the two basic components in weaving to transform thread and yarn into textile fabrics. The vertical warp yarns are held stationary in tension on a loom (frame) while the horizontal weft (also the woof) is drawn through (inserted) over and under the warp thread. In the terminology of weaving, each warp thread is called a warp end; a pick is a single weft thread that crosses the warp thread, synonymous terms are fill yarn and filling yarn.
- 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.
