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Benvenuti in queste pagine dedicate a scienza ed arte. Amelia Carolina Sparavigna

Thursday, August 22, 2013

Moving sand dunes on Mars

Moving Sand Dunes on Mars, by Amelia Carolina Sparavigna, Department of Applied Science and Technology, Politecnico di Torino, Torino, Italy

Abstract: It was recently announced that the sand dunes on Mars can move. This important result was obtained by means of the High Resolution Imaging Science Experiment (HiRISE), the camera onboard the Mars Reconnaissance Orbiter. The images, recorded three years apart, of the dunes in the Nili Patera caldera show that they move. Here we compare an image HiRISE of 2007 with an image of 1999 recorded by the Mars Global Surveyor. Therefore, with the help of Gimp, the GNU image processing software to enhance the images, we can see and measure the motion of the dunes during a longer period of time.

A dune on Mars which is moving. In the Nili Patera caldera.
199 on the left, 2007 on the right


More details and article at:


Thursday, August 15, 2013

Peruvian dunes (Google Earth)



http://staff.polito.it/amelia.sparavigna/DUNE/

"Moving Dunes on the Google Earth" at http://arxiv.org/abs/1301.1290
(where I show how to use the time series of the Google Earth to estimate the motion of the barchans. I discuss also how to use reference points and adjust the Google images to have a "movie")

"A Study of Moving Sand Dunes by Means of Satellite Images"

Sunday, August 11, 2013

From Google Earth to Tatooine

Today (11 August 2013)  I found this article entitled "Star Wars home of Anakin Skywalker threatened by dune" http://www.bbc.co.uk/news/science-environment-23375344
It is told that "Sand dunes migrating over the Tunisian desert are poised to bury a famous Star Wars film set. The buildings of the fictional city Mos Espa featured in The Phantom Menace, "Episode I" of the Jedi saga. Sited on the planet Tatooine, this was the home of the young Anakin Skywalker ... Scientists have used the dwellings as a fixed geographic reference to measure the migration of giant wind-blown crescent-shaped dunes, or barchans. They have published details in the journal Geomorphology." The paper is in press, and you can see it at  http://www.sciencedirect.com/science/article/pii/S0169555X13003486
BBC continues "Ralph Lorenz, from Johns Hopkins University, ...  visited the Mos Espa site in 2009, and noted that part of a nearby set used in Star Wars Episode IV: A New Hope had already been overrun. Using satellite images of the site, they were able to determine the speed of dune movement, which is approaching the buildings once inhabited by such luminaries as Anakin, his slave owner Watto, and rival podracer Sebulba".
Before these "Dunes on the planet Tatooine",  on 4 January 2013 it was published  my "Moving Dunes on the Google Earth", as you can find at http://arxiv.org/abs/1301.1290, where I showed how to use the time series of the Google Earth to estimate the motion of the barchans. I used the barchans in Peru. I have also  discussed how to use reference points and adjust the Google images to have a "movie".
It seems that the authors of "Dunes on planet Tatooine: Observation of barchan migration at the Star Wars film set in Tunisia" do not know my "Moving dunes on the Google Earth" because my paper is not cited.
Therefore I cite myself!

And show you a "movie" of the barchan which is threatening Luke Skywalker's home.








Moving sand dunes on the Google Earth

"Moving dunes on the Google Earth" is my paper on arXiv, published 4 January 2013. It shows how using GH time series you can see the motion of dunes. Here an example.


To see a movie, please visit Moving sand dunes ... post