Planets rich in carbon, including so-called diamond planets, may lack oceans, according to NASA-funded theoretical research. This artist’s concept illustrates the fate of two different planets: the one on the left is similar to Earth, made up largely of silicate-based rocks with oceans coating its surface. The one on the right is rich in [continue reading]
Using ESA’s Herschel space observatory, astronomers have discovered vast comet belts surrounding two nearby planetary systems known to host only Earth-to-Neptune-mass worlds. The comet reservoirs could have delivered life-giving oceans to the innermost planets. Artist impression of the debris disk and planets around the star known as Gliese 581, superimposed on Herschel PACS images [continue reading]
Debate over the origin of large-scale polygons (hundreds of meters to kilometers in diameter) on Mars remains active even after several decades of detailed observations. Similarity in geometric patterns on Mars and Earth has long captured the imagination. Geologists at The University of Texas at Austin examine these large-scale polygons and compare them to similar [continue reading]