NASA announced this morning the selection of Jezero crater for the landing site of the Mars 2020 mission. Jezero is a 45-kilometer-wide crater that once held a lake, and now holds a spectacular ancient river delta.
Petrology is a field of science in which scientists study the compositions of rocks and minerals and interpret their geologic history. A common graph petrologists use is the “pyroxene quadrilateral.” These graphs, like photos of space, can reveal an understanding of the remotest parts of the solar system.
One of the Cassini mission's goals was to figure out how long a day on Saturn is. We still don't know. A new paper reports a measurement of the rotation period of Saturn that is different from past measurements.
What is the surface of a comet like? That's one of the main questions that motivated Philae's mission to the surface of comet 67P/Churyumov-Gerasimenko. We now know the comet has a rigid crust about 10 to 50 centimeters thick, below which the comet is much more fluffy.