lfenton

January 16, 2014

Lines, lines

A piece of Mars: On martian dunes it’s all about lines, lines, lines. The prominent wavy ones on the left are thought to be erosional scars left by sliding blocks of dry ice. The little fingerprint-like lines are ripples, like […]
January 13, 2014

Mars’ fleets of rock “boats”

A piece of Mars: Where the wind blows strong and there’s a lot of sand, the surface gets scoured. Some bits of the ground, called yardangs, are more resistant and stick around: they take on shapes elongated in the direction […]
January 8, 2014

Bearded hills

A Piece of Mars: Bright hills appear to be bearded (or perhaps mustached?). What’s going on? Dark sand has blown over some yellow-crested hills and settled on the downwind side, where the hill blocks enough wind that it can no […]
December 27, 2013

Wintery dune

A piece of Mars: A single dune sits on the surface of Mars, not too far from the north pole. It’s early spring, but this far north the dune is still covered in white CO2 frost (as well as a […]
December 23, 2013

Growth of ripples over time… a long time.

A piece of Mars: Normally I post color images, but this one is just too cool to skip. These ripples formed ages ago: long enough ago that the impact of several small bolides formed craters (seen on the left), disrupting […]
December 11, 2013

The holes get filled in

A piece of Mars: Sand that moves into holes in the ground tends to get stuck there. That’s why this round hole ~150 m across, which was probably once a crater, is now brimming with sand and capped by ripples. […]
November 29, 2013

Two-toned washboard on a hillside

A Piece of Mars: Two-toned ripples have formed on a steep slope, created by winds rushing downhill (from top to bottom in this frame). The larger ones are big ripples, with peaks more than 30 meters apart. What makes them […]
November 25, 2013

Cloaked rocks

A Piece of Mars: These rocks look like hooded figures from some dark fantasy story. European standing stones should be jealous, they don’t typically get a shroud of dark sand to add to their mystery and etch them into beguiling […]
November 18, 2013

It’s a comet! No, wait…

A piece of Mars: Is it a comet? With Comet ISON in the news these days it’s hard to tell. No, this is a brand-new meteorite impact on the surface of Mars. The impactor hit the ground, blasted through a […]