• MAA-011: Disc Shaped Feature

- Image Analysis Report

Image Analysis Report

IMAGE DETAILS

MAA Report Ref: MAA-011

Report Date: July-August 2017

Research Status: Explained

Description: Disc Shaped Feature
Approximate size: 150 m

Mission image/date: MGS August 2000

Image pixel width: 2.90 m
Location: Aram Chaos

Found by: Bret Colin Sheppard

Image credits: NASA/JPL/MSSS

Graphics/image editing: Mars Archaeology Archive

Image source: (See image captions)

OBSERVATIONS

The non-map projected image taken by MOC/MGS, gives the impression of a metal disc shape reflecting sunlight. However as the image was taken from directly overhead, the perceived viewing angle of this object is an illusion. The map-projected image gives a clearer impression of the true shape of this feature that is partially covered by sand dunes. The specular reflections on the 'disc' also follow a line which runs parallel with ridges of rock strata. Due to MSSS recently handing their image database over to NASA/PDS, we have not yet been able to locate the original image links for the map and non-map versions which we show below in MAA-011.1 and MAA.011.2.

​POTENTIAL FOR AN ARTIFICIAL STRUCTURE

None. Feature satisfactorily explained by geology.

COMMON EXPLANATION

ACCEPTED - Illusion caused by incorrect image perspective.

MAA-011.1 Disc Shaped Feature -  Comparison with 'map' and 'non-map' projected images - MGS 2000

​Image credit: NASA/JPL/MSSS

Graphics/image editing: Mars Archaeology Archive

Image sources: Original MSSS source links no longer work (images shown above). However a PDS image source was found for the Non-map version (see last link below)

Non-map projected http://www.msss.com/moc_gallery/m13_m18/full_gif_non_map/M18/M1800558.gif

Map projected: http://www.msss.com/moc_gallery/m13_m18/full_gif_map/M18/M1800558.gif

PDS image source non-map projected: https://ida.wr.usgs.gov/fullres/divided/m18005/m1800558e.jpg

MAA-011.2 Disc Shaped Feature - Comparison of MRO Context Camera (CTX) image with MOC images

​Image credit (1): NASA/JPL/MSSS

Graphics/image editing: Mars Archaeology Archive

Image pixel width: 6.32 m

Image source: (MRO Context CTX) http://viewer.mars.asu.edu/planetview/inst/ctx/G11_022486_1821_XN_02N020W#P=G11_022486_1821_XN_02N020W&T=2

(When viewing the full MRO CTX image, zoom in and you will find this object at the very top right of the picture)