January 31, 2018
I set my alarm for 5:30 this morning. Sometimes I skip lunar eclipses, but I do try to see them if they’re total, and if I think the sky might be cloud-free (which it often isn’t in the Bay Area […]
January 30, 2018
A Piece of Mars: The dark splash pattern in this 0.9×0.9 km (0.56×0.56 mi) scene (click on it for a better view) is the site of an impact crater that appeared between images sometime between August 2006 and March 2010 […]
January 22, 2018
A Piece of Mars: This is a section of Arnus Vallis (scene is 1.25×1 km, 0.78×0.62 mi). It’s a >300 km long valley that was carved out, not by water, but by lava, long ago. Since then the wind has […]
January 18, 2018
A Piece of Mars: This 0.5×0.4 km (0.31×0.25 mi) scene shows two dunes near the north pole. The shape of the dunes indicates two main winds: one blowing left to right (which makes slip faces on the right side, one […]
January 8, 2018
A Piece of Mars: The north polar dunes in this 575×325 m (0.36×0.2 mi) scene are made of dark sand covered by bright winter frost (which will soon sublimate away, as this image was taken in late spring). To the […]
January 2, 2018
A Piece of Mars: The dunes (or maybe they’re ripples) in this valley appear to be fuzzy (the view is 625×775 m, 0.39×0.48 mi). They’re not really fuzzy, but it’s not actually clear what’s going on. They seem to have […]
December 26, 2017
A Piece of Mars: To see this one well you’ll have to click on the image. At the lower right, a 240 m (787 ft) diameter crater formed when a bolide hit the surface, throwing out ejecta on the surrounding […]
December 18, 2017
A Piece of Mars: Some things just go unexplained (so far, anyway). Here’s a mysterious bright streak (scene is 1.2×1.8 km, 0.75×1.12 mi) concentrated between two sets of ripple-like bedforms. It looks sort of like a river, but it’s on […]
December 11, 2017
A Piece of Mars: Look at the alignment of the ~100 m dunes in this 713×750 m (0.44×0.47 mi) scene. How do dunes form in such straight lines? And why don’t they always do that? It’s likely that these dunes […]