Category: Uncategorized

Two directions

A Piece of Mars: Sometimes I just want to show the interior of a dune field, because it's full of waves: ripples and dune crests, slip faces, all of which signs of movement. The dunes in this 0.67x0.47 km (0.41x0.29 ...

Where on Mars is this dune?

A Piece of Mars: This 0.48x0.27 km (0.3x0.17 mi) scene shows a rotund barchan dune. Can you tell from looking at it where on Mars it might be? To me the most obvious feature are the bumpy piles at the ...

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, ...

The trail of a dune

A Piece of Mars: A low, broad dune occupies the center of this 800x450 m (0.5x0.28 mi) scene, blown by a dominant wind towards the lower left. The slip face on the lee side has several small avalanches, formed as ...

The spire in Eberswalde crater

A Piece of Mars: OK, you have to bring out the red/blue glasses for this one. (Or click here if you're missing your glasses and want the black and white version.) Eberswalde crater has some lovely layered deposits, long ago ...

Neverending dust

A Piece of Mars: Some parts of Mars, like this one, are very dusty. This 1.92x1.1 km (1.2x0.67 mi) area has built up a thick deposit of dust that slowly buries the impact craters until they're mere ghosts of the ...

Sizes of worlds

A Piece of the Solar System: This isn't my usual sort of post. But lately my 6 year old kid has been into planets, and thanks to the many informative videos on YouTube, has been reciting various names and numbers ...

The smallest dunes

A Piece of Mars: There are two small dome-shaped dunes in this frame (0.96x0.54 or 0.6x0.33 mi). If they got any larger, they'd form slip faces. Any smaller and they'd just be random drifts of windblown sand. Dunes form at ...

Curiosity about sand dunes (part 2/2)

Today is December 21, 2015 (northern winter and southern summer solstice on Earth). On Mars it is Ls = 84ยบ, Mars Year 33 (about 12 sols from northern summer and southern winter solstice on Mars). It is sol 1200 of ...

NASA Mars acronym fun

Today I've got something different. Today NASA announced the discovery of hydrated salts in some dark slope features that form during the spring on Mars. These "recurring slope lineae", or RSLs, were discovered a few years back, and they form ...