Tessera

Tessera

. Beccause there is little soil and no egetation or erosion to confuse us, we can see tectonic paterrns on Venus much more easily than on our own planet. This region, covering an area of 37 thousand meters by 80 thousand meters long, is located at 30 degrees north latitude and 333 degrees east longitude, on the low rise separating Sedna Planitia and Guinevere Planitia. It shows a criss-crossed pattern of radar-bright lines which appear to be faults or fractures. The orthogonal system of ridges and grooves is formed in elevated terrain (by 1 or 2 thousand meters), and spaced at regular intervals of 1 to 20 thousand meters. Known as tessarae, from the Latin word for “tiles”, the features suggest repeated episodes of intense surface fracturing that may be unrelated to volcanic activity. This type of terrain is not seen on any other planet. It covers about 8 percent of Venus's surface. Although tessarae are the oldest visible landform on Venus, they are young by planetary standards, having formed within the last billionb years. Sedna is an Eskimo goddess whose fingers became seals and whales, and Guinevere is the legendary Queen of the British King Arthur. (Courtesy of NASA.)

Copyright 2010, Professor Kenneth R. Lang, Tufts University