- 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.
- Marfik (stars.astro.illinois.edu)
MARFIK (Lambda Ophiuchi). Double stars are among the prettiest sights the sky has to offer. The best ones, like Albireo and many others, display striking color contrasts that are enhanced by visual proximity effects. But even the white “colorless” ones are attractive, especially if the two members are close together. Those of Marfik (the “elbow” of Ophiuchus), or Lambda Ophiuchi, are so close that they are, however, difficult to separate at the telescope, averaging just a second of arc – a 3600th of a degree – apart.
