geology – Page 6 – planetaria

Mystery solved? odd bright spots on Ceres explained as salt deposits

December 11, 2015 by Paul Scott Anderson

False color view of Occator crater on Ceres, showing the unusual bright spots. The image was taken by the framing camera on NASA’s Dawn spacecraft from a distance of about 2,700 miles (4,400 kilometers). Image Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA — False color view of Occator crater on Ceres, showing the unusual bright spots. The image was taken by the framing camera on NASA’s Dawn spacecraft from a distance of about 4,400 kilometres (2,700 miles). Image Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA

There now might be a definitive answer to a puzzle which has intrigued both scientists and the public for some time: What are those odd bright spots on the dwarf planet Ceres? A new study suggests they are a type of salt, originating from a subsurface layer of briny water-ice. Another study points to the existence of ammonia-rich clays on Ceres.

NASA’s Curiosity rover approaching active Martian sand dunes after latest drilling completed

November 18, 2015 by Paul Scott Anderson

The edge of a dark sand dune field can be seen in this white-balanced Curiosity image from sol 1115 (Sep. 25, 2015). Image Credit: NASA/JPL-Caltech/MSSS

Mars is often referred to as a desert world, being bone-dry for the most part, with dust and sand blanketing most of the surface. Some regions are covered in vast sand dunes, reminiscent of deserts like the Sahara on Earth, only much colder. Gale crater, where the Curiosity rover landed in 2012, features extensive dune fields around the base of Mount Sharp, and the rover is now approaching some of them for the first time; their dark color makes them stand out starkly against the surrounding terrain. These dunes are also still active, meaning they are still mobile and shaped by the wind, not just old “fossil” (petrified) dunes which are no longer active.

A complex world: Pluto discoveries include possible ice volcanoes, varied geology and weird spinning moons

November 12, 2015 by Paul Scott Anderson

Slide from the DPS meeting showing possible ice volcanoes on Pluto. Image Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute

Pluto is a small, cold world, but it is also turning out to be one of the most fascinating places in our Solar System – as reported this week at the American Astronomical Society’s Division for Planetary Sciences (DPS) meeting in National Harbor, Maryland, images and other data have revealed possible ice volcanoes and other surprisingly diverse geology as well as weirdly spinning moons.

Data from Spirit rover provides evidence for acid fog on ancient Mars

November 4, 2015 by Paul Scott Anderson

False-color mosaic of Cumberland Ridge, with pie charts representing iron-bearing mineralogy. Image Credit: S. Cole, PhD thesis; background image: NASA/JPL/Cornell/Arizona State University; Moessbauer values from Morris et al. 2008 (doi: 10.1029/2008JE003201) — False-colour mosaic of Cumberland Ridge, with pie charts representing iron-bearing mineralogy. Image Credit: S. Cole, PhD thesis; background image: NASA/JPL/Cornell/Arizona State University; Moessbauer values from Morris et al. 2008 (doi: 10.1029/2008JE003201)

The various rover and lander missions on Mars have provided unprecedented glimpses into the planet’s past, including geological history and environmental conditions. In many ways, ancient Mars was similar to Earth, with abundant water and volcanic activity. Now, new research has revealed that there was also another related Earth-like phenomenon: acid fog.

Curiosity rover confirms ancient lake(s) in Gale crater on Mars

October 11, 2015 by Paul Scott Anderson

Sedimentary strata at the base of Mount Sharp as seen at the Kimberly location. The strata in the foreground dip toward Mount Sharp, providing evidence of the former lake-filled depression that used to exist before most of the mountain formed. Image Credit: NASA/JPL-Caltech/MSSS

Last week there was the exciting news that Mars still has flows of briny water occurring now, and this week there is more water-related news: additional findings from the Curiosity rover that the huge Gale crater was once a lake or series of lakes a long time ago. Curiosity had already found evidence that there used to be shallow lakes and streams in this area, but the new data confirms this and suggests that the lake(s) once filled Gale crater and were long-lasting, explaining the formation of Mount Sharp in the middle of the crater and also providing a potentially habitable environment for life.

+ More