crater

March 12, 2018

Wind on Mars and the Huygens-Fresnel Principle

How about some basic physics? It’ll be easy, I promise. Just look at the pretty picture below (click on it to see it better): (HiRISE ESP_045586_1585, NASA/JPL/Univ. of Arizona) The big crater is ~400 m (1/4 mile) across. Wind blows […]
January 30, 2018

Smash! Whoosh…

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 […]
December 26, 2017

Buried by ejecta

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 […]
August 28, 2017

Endless wind

A Piece of Mars: This 2.88×1.13 km (1.79×0.70 mi) scene shows quintessential Mars, with a 670 m diameter impact crater heavily modified by wind erosion. Both the crater floor and the surrounding terrain are covered by what is likely loosely-cemented […]
August 14, 2017

Wind and maybe water too

A Piece of Mars: Along the right side of this 0.5×0.5 km (0.31×0.31 mi) scene is the rim of a crater – the stripes are layers exposed (and then perhaps draped by falling ejecta) as the crater formed. To the […]
May 8, 2017

Sand tails

A Piece of Mars: Up on the tallest volcanoes, the wind screams downhill at night. This 500x500m (0.31×0.31 mi) scene shows how dust is carried downhill, but only that which is trapped behind boulders and crater rims sticks around. The […]
April 24, 2017

The bowl of windstuff

A Piece of Mars: Get out your red and cyan glasses to see an old crater, which fills this 0.775×0.7 km (0.48×0.43 mi) scene. The crater punched through many thin layers when it formed, some of which you can still […]
February 13, 2017

Mars’ yin-yangs

A Piece of Mars: Is this 480×270 m (0.3×0.17 mi) scene showing a 150 m (492 ft) wide yin-yang symbol on Mars? Sort of, maybe, if you blur your eyes and lend me artistic license, but it’s not doing so […]
January 23, 2017

Mars’ giant sweaters

A Piece of Mars: Sometimes in the floors of small craters, the wind blows in from several directions to produce odd polygon-shaped dunes that look like crochet (maybe Mars is making sweaters for its craters – it is, after all, […]