Encyclopedia of Planetary Landforms

2015 Edition
| Editors: Henrik Hargitai, Ákos Kereszturi

Dark Splotch (Albedo Feature)

  • Daniela Tirsch
Reference work entry
DOI: https://doi.org/10.1007/978-1-4614-3134-3_103


Dark patches on the surface of Mars that can be elongated in wind direction.


A type of  albedo feature on Mars

A type of dark deposit on Mars


 Low albedo markings; Variable features (Sagan)


A dark irregular zone having a mottled appearance in images of Mars as seen with Mariner 9 resolution and low to moderate Viking resolution. Dark splotches are often associated with tongue-like streaks. They have a characteristic dimension between several to tens of km, are often found inside impact craters or “washed over crater walls,” and are controlled by topography (Sagan et al. 1972; Thomas 1984). Splotches are in fact fields (ergs) of dark dunes when observed at higher resolution (  dark deposits (Mars)). Their low albedo suggested that the sand is silica poor in composition. Dark splotches have been observed in topographical depressions: craters (crater splotches), troughs, and canyons (Thomas 1984). The Oxia Palus region was prominent for its...
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  1. Greeley R, Iversen JD (eds) (1985) Wind as a geological process on Earth, Mars, Venus and Titan. Cambridge University Press, CambridgeGoogle Scholar
  2. Sagan C, Veverka J, Fox P, Russell D et al (1972) Variable features on Mars: preliminary Mariner 9 television results. Icarus 17:346–372CrossRefGoogle Scholar
  3. Thomas P (1984) Martian intracrater splotches: occurrence, morphology, and colors. Icarus 57:205–227CrossRefGoogle Scholar

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© Springer Science+Business Media New York 2015

Authors and Affiliations

  1. 1.German Aerospace Center (DLR)Institute of Planetary ResearchBerlinGermany