Hebrus Valles

The Hebrus Valles are an ancient system of troughs and valleys in the Amenthes quadrangle of Mars, located at 20.2° north latitude and 233.4° west longitude. They are 317 km long and were named after a river in the Balkans which runs through present day Bulgaria, Greece and Turkey. Some authors have identified the troughs and valleys of Hebrus Valles as outflow channels, but their origin and history remain ambiguous.^[1] It has been considered as a potential site for human exploration due to the presence of icy caves.^[2]

Hebrus Valles

The Hebrus Valles, as seen by THEMIS. Direction of flow was determined by shape of streamlined islands. Terraces may reflect the occurrence of multiple flood events.
Coordinates	20.2°N 233.4°W / 20.2; -233.4

Geology

The Hebrus Valles have tributaries, terraces, and teardrop shaped islands. These features are all characteristic of erosion by fluid flow, but may or may not support the identification of this feature as carved by a single catastrophic outburst flood of water (as the term outflow channel would imply).^[1] The flood would have occurred during the early Amazonian.^[3] There is also an extensive cave network which is expected to contain water ice.^[2]

• 
  The Hebrus Valles, as seen from Themis. Since discontinuous pits and troughs are present, it is believed the troughs were created by collapse of surface material into voids.

See also

• Geology of Mars
• Outflow channels

References

1. Carr, M.H. (2006), The Surface of Mars. Cambridge Planetary Science Series, Cambridge University Press.
2. Schulze-Makuch, D.; Davila, A.; Fairen, A. G.; Rodriguez, A. P.; Rask, J.; Zavaleta, J. (2016-09-01). "Ice Caves in Hebrus Valles: A Target Location for the First Human Mission to Mars". Sixth International Conference on Mars Polar Science and Exploration. 1926: 6014. Bibcode:2016LPICo1926.6014S.
3. Nerozzi, S.; Tober, B.; Holt, J. W.; Ortiz, M. (December 2020). "Reconstructing the geologic history of Hebrus Valles and Hephaestus Fossae, Mars with SHARAD". AGU Fall Meeting Abstracts. 2020: 016–0004. Bibcode:2020AGUFMP016.0004N.