Martian Pie Shell

Credit: NASA/JPL/University of Arizona

Gul­lies and debris lit­ter the bot­tom of this Mar­t­ian crater mak­ing it resem­ble a pie shell that has been dropped.

Explore this image from NASA’s HiRISE cam­era aboard the Mars Recon­nais­sance Orbiter of a small crater. What other shapes and sto­ries does your imag­i­na­tion see in this image? Leave a note below.

While there is no sub­stan­tial sur­face water on Mars to cre­ate gul­lies, wind and debris flows can cre­ate sim­i­lar fea­tures. These gul­lies are found on the pole fac­ing slopes. Per­haps freez­ing and thaw­ing action has caused much debris from the rims to flow to the crater floor. Geol­o­gists the­o­rize that some of the snaky ridges on the crater floor could be moraines. Moraines are places where boul­ders, stones, sand and dirt accu­mu­late after being bull­dozed by other processes. On Earth, moraines are usu­ally asso­ci­ated with glac­i­ers. On Mars, how­ever, this debris could pile up as other rock and sand accu­mu­late behind them.

As you explore the crater, look for dunes in the bot­tom of the crater along the edges. They cre­ate right angles with the crater edge as if the wind swirls in the bot­tom of the crater. Can you pick out other dunes inside the crater?

This small crater is part of a larger crater known as New­ton Crater. Named after Sir Isaac New­ton, New­ton Crater is about 300 kilo­me­ters (or 186 miles) in diam­e­ter. It sits in the heav­ily cratered high­lands of Terra Sirenum in the south­ern hemi­sphere of Mars. A low area in the high­lands is believed to have once con­tained a lake that even­tu­ally drained and dried up.

Launched with Mars Recon­nais­sance Orbiter, or MRO, in 2005, HiRISE is one of six instru­ments aboard the space­craft orbit­ing Mars. HiRISEs cam­era can see objects on the sur­face as small as a beach ball. The instru­ment can also offer sci­en­tists stereo views of the surface.