Categories: Astronomy

Beautiful Exposed Bedrock and Sand Dunes on Mars

Impact craters can be quite complex. Depending on the size of the impactor, and on the size of the planet it strikes, craters form differently. Some form central peaks or uplifted structures, or even pits as seen in this image.

This image is the HiPOD, or the HiRISE (High Resolution Imaging Science Experiment) Picture of the Day. HiPOD’s are a selection of outstanding or particularly significant images of Mars from the HiRISE instrument on NASA’s Mars Reconnaissance Orbiter (MRO).

In this crater the central pit exposes bedrock with different colors. Each different color is a different bedrock “unit” with a different composition. In this crater, the CRISM (Compact Reconnaissance Imaging Spectrometer for Mars) instrument on the MRO identified clay-rich minerals.

NASA also released this cut-out of the eastern half of the central pit.

A cut-out image of the eastern part of the crater, highlighting the exposed bedrock. Image Credit: NASA/JPL/UArizona

Larger craters tend to be the most complex, due to the energy involved. The characteristics of the surface material and the underlying material also play a role in the formation of central pits. There are many suggested mechanisms for these central pits, but overall they’re not well understood.

A 2019 paper proposed several mechanisms:

  • explosive release of water vapor
  • uplift and collapse of rock at the crater centers
  • drainage of liquid, produced by the impact, into cracks in the crater floor
Three mechanisms behind crater central pits. Image Credit: Peel et al; 2019.

That same study couldn’t determine any single cause of these central pits, but suggested that multiple mechanisms may be responsible.

You can follow the HiRISE POD at the HiRISE website.

Evan Gough

Recent Posts

Scientists Have Figured out why Martian Soil is so Crusty

On November 26th, 2018, NASA's Interior Exploration using Seismic Investigations, Geodesy, and Heat Transport (InSight)…

8 hours ago

Another Way to Extract Energy From Black Holes?

Black holes are incredible powerhouses, but they might generate even more energy thanks to an…

13 hours ago

Plastic Waste on our Beaches Now Visible from Space, Says New Study

According to the United Nations, the world produces about 430 million metric tons (267 U.S.…

1 day ago

Future Space Telescopes Could be Made From Thin Membranes, Unrolled in Space to Enormous Size

As we saw with JWST, it's difficult and expensive to launch large telescope apertures, relying…

2 days ago

Voyager 1 is Forced to Rely on its Low Power Radio

Voyager 1 was launched waaaaaay back in 1977. I would have been 4 years old…

2 days ago

Webb Confirms a Longstanding Galaxy Model

The spectra of distant galaxies shows that dying sun-like stars, not supernovae, enrich galaxies the…

3 days ago