This Magellan image of the Lakshmi Region of Venus was taken on September 15, 1990. The image is a mosaic of orbits 376 and 377 and shows features on the surface of Venus at 36 north latitude, 330 east longitude. The image measures 41 x 77 kilometers (25 x 48 miles) and shows the dark, randomly fractured plains of Sedna Planitia. The circular feature in the center of the image is a relatively flat-topped dome, 13 x 20 kilometers (8 x 12.5 miles) in diameter at the top and 28 by at least 35 kilometers (17 x 22 miles) in diameter at the base. The top of the dome is highly fractured in a radial pattern; wider troughs extend downslope on the north and southeast flanks. The fractures in the plains deflect in a circumferential pattern around the base of the dome. A similar pattern to the west of the dome indicates the presence of a second dome to the left, off the image. Since no lava flows are observed to emanate from the dome, this feature may be a failed volcano, known as a "cryptodome." Cryptodomes form on Earth when molten rock rises but is unable to break through to the surface as lava flows. The overlying rock is bowed up, possibly fracturing the surface and forming a flat-topped dome.
