Mudstone for silt (63 μm). On December 13, 2016, NASA reported further evidence supporting habitability on the planet Mars as the "Curiosity" rover climbed higher, studying younger layers, on Mount Sharp. Also reported, the very soluble element boron was detected for the first time on Mars. In June 2018, NASA reported that "Curiosity" had detected kerogen and other complex organic compounds from mudstone rocks approximately 3.5 billion years old. Mudstone Mudstone, a type of mudrock, is a fine-grained sedimentary rock whose original constituents were clays or muds. Grain size is up to with individual grains too small to be distinguished without
Gliese 687 X-rays. Gliese 687 Gliese 687, or GJ 687 "(Gliese–Jahreiß 687)" is a red dwarf in the constellation Draco. This is one of the closest stars to the Sun and lies at an approximate distance of less than 15 light years. Even though it is close by, it has a magnitude of about 9, so it can only be seen through a moderately sized telescope. Gliese 687 has a high proper motion, advancing 1.304 arcseconds per year across the sky. It has a net relative velocity of about 39 km/s. It is known to have a Neptune-mass planet. Gliese 687 has