Today's Image of Mars shows two distinctive layers exposed in a 230m wide crater caused by a meteorite impact in the Northern Plains. The impact excavated material from both layers at different rates because the layers are different densities. If you want to conduct an experiment to see how this happens, follow these steps:
- Fill a bowl halfway with water and freeze it.
- After it's frozen, place a layer of sugar (powdered or granular) over the surface.
- (This is the messy part) Take a marble or other hard object and throw it down into the bowl. (The impact will eject a lot of sugar from the surface)
- Carefully remove the marble.
- Take a photo from above. You will notice that the marble made more of an impact in the sugar, but faced increased resistance when it hit the ice.
This is a simplified version of what happened when the meteorite created this impact. The layer under the surface was denser so the meteorite faced much more resistance and excavated the material at a much lower rate, as seen below.
|Click for high resolution image from HiRISE. [See their caption]|
Radar images taken by SHARAD, the radar instrument aboard the Mars Reconnaissance Orbiter indicate the presence of ice below the surface, which makes this area a potential site for future exploration of Mars. If we can access ice beneath the surface of Mars then we could use it not only for sustenance, but as a source of fuel for future missions to Mars.