by Paul Scott Anderson
part of the heavily cratered southern highland region of the planet Mars.
The interesting patterns of the dunes themselves are contained
within a boundary that is roughly hexagon-shaped.
NASA/JPL-Caltech/Arizona State University.
NASA's Odyssey orbiter has revealed
something odd: a large dune field
shaped roughly like a hexagon.
The finding is expected to provide
more clues as to how dunes form
in Martian winds.
Although there are many of the same atmospheric and geological processes as on Earth, they can take on unusual forms not seen on our planet.
The Mars rovers have discovered, for one example, very thin and delicate rock formations that are common in Mars' lower gravity and thinner atmosphere (although similar ones can be found on Earth as well).
Mars is also covered in sand dunes, much like those in earthly deserts.
Mars Odyssey orbiter recently took photos of a dune field that
- unlike any dune field seen on Earth - has a strange-looking, roughly
hexagonal shape. It's not a perfect hexagon, but close enough to
make you take notice.
As explained on ASU's Flickr page:
strange hexagonal dune field on Mars.
Image via NASA/JPL-Caltech
Arizona State University.
Dust devils are common on Mars, just as they are on Earth, despite Mars' thinner atmosphere. They have even been photographed in-action by the,
commented on the hexagonal dune field on Twitter:
As Fenton also noted, there is a second similar formation nearby, in another crater.
Not quite as hexagonal, but still interesting.
As to how the dune fields formed the way they did, Fenton expressed some ideas via Twitter:
There is also a
close-up view of the dunes themselves, from the
HiRISE camera on NASA's Mars Reconnaissance Orbiter.
Most of the landers and rovers on Mars have seen dunes and drifts up close, a chance to study them in detail as to their composition and how they can form - even up to about 20 feet (6 meters) tall, like ones in the Bagnold Dune Field seen by Curiosity - in such a thin atmosphere.
Close-up view of the dunes themselves,
from the Mars Reconnaissance Orbiter.
Image via NASA/JPL/University of Arizona.
Scientists, including Fenton, will examine them closely to figure out the processes involved in their formation. Fenton had also recently written about another dune field on her blog that has similar crisp edges, but a different shape.
She proposed two ideas for how these types of southern latitude dune fields - slower and more eroded - form:
at Saturn's north pole,
as seen by the Cassini spacecraft in 2014.
Image via NASA.
Hexagons can be found in other places in nature. Another striking example is the jet stream formation at Saturn's north pole, which is a massive, near-perfect hexagon centered at the pole itself.
These odd dune fields seen by the Odyssey orbiter
- with one having a roughly hexagonal shape - are an interesting
puzzle for planetary scientists, and are expected to help provide
more clues about wind-driven dune formation processes on Mars.
from YouTube Website