Small variations in ice composition and layer thickness explain bright reflections below martian polar cap without liquid water
Abnormally bright radar reflections below the Martian south polar layered deposit were originally interpreted as evidence of subglacial liquid water. However, unlike on Earth, conditions beneath the Martian ice are too cold to create or maintain meltwater. In this work, we use radar reflectivity sim...
Published in: | Science Advances |
---|---|
Main Authors: | , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
American Association for the Advancement of Science (AAAS)
2024
|
Subjects: | |
Online Access: | http://dx.doi.org/10.1126/sciadv.adj9546 https://www.science.org/doi/pdf/10.1126/sciadv.adj9546 |
id |
craaas:10.1126/sciadv.adj9546 |
---|---|
record_format |
openpolar |
spelling |
craaas:10.1126/sciadv.adj9546 2024-06-23T07:53:47+00:00 Small variations in ice composition and layer thickness explain bright reflections below martian polar cap without liquid water Lalich, Daniel E. Hayes, Alexander G. Poggiali, Valerio 2024 http://dx.doi.org/10.1126/sciadv.adj9546 https://www.science.org/doi/pdf/10.1126/sciadv.adj9546 en eng American Association for the Advancement of Science (AAAS) Science Advances volume 10, issue 23 ISSN 2375-2548 journal-article 2024 craaas https://doi.org/10.1126/sciadv.adj9546 2024-06-13T04:01:41Z Abnormally bright radar reflections below the Martian south polar layered deposit were originally interpreted as evidence of subglacial liquid water. However, unlike on Earth, conditions beneath the Martian ice are too cold to create or maintain meltwater. In this work, we use radar reflectivity simulations to show that the strong reflections can instead be caused by constructive interference between dusty ice layers that are more closely spaced than the radar resolution. Unlike previous hypotheses, interference does not require anomalous subsurface conditions or exotic materials to be present beneath the ice. In addition, interference between thin layers can explain the variable power of radar returns beneath the entire ice sheet and does not require different mechanisms to be responsible for reflections in different regions. Article in Journal/Newspaper Ice Sheet AAAS Resource Center (American Association for the Advancement of Science) Science Advances 10 23 |
institution |
Open Polar |
collection |
AAAS Resource Center (American Association for the Advancement of Science) |
op_collection_id |
craaas |
language |
English |
description |
Abnormally bright radar reflections below the Martian south polar layered deposit were originally interpreted as evidence of subglacial liquid water. However, unlike on Earth, conditions beneath the Martian ice are too cold to create or maintain meltwater. In this work, we use radar reflectivity simulations to show that the strong reflections can instead be caused by constructive interference between dusty ice layers that are more closely spaced than the radar resolution. Unlike previous hypotheses, interference does not require anomalous subsurface conditions or exotic materials to be present beneath the ice. In addition, interference between thin layers can explain the variable power of radar returns beneath the entire ice sheet and does not require different mechanisms to be responsible for reflections in different regions. |
format |
Article in Journal/Newspaper |
author |
Lalich, Daniel E. Hayes, Alexander G. Poggiali, Valerio |
spellingShingle |
Lalich, Daniel E. Hayes, Alexander G. Poggiali, Valerio Small variations in ice composition and layer thickness explain bright reflections below martian polar cap without liquid water |
author_facet |
Lalich, Daniel E. Hayes, Alexander G. Poggiali, Valerio |
author_sort |
Lalich, Daniel E. |
title |
Small variations in ice composition and layer thickness explain bright reflections below martian polar cap without liquid water |
title_short |
Small variations in ice composition and layer thickness explain bright reflections below martian polar cap without liquid water |
title_full |
Small variations in ice composition and layer thickness explain bright reflections below martian polar cap without liquid water |
title_fullStr |
Small variations in ice composition and layer thickness explain bright reflections below martian polar cap without liquid water |
title_full_unstemmed |
Small variations in ice composition and layer thickness explain bright reflections below martian polar cap without liquid water |
title_sort |
small variations in ice composition and layer thickness explain bright reflections below martian polar cap without liquid water |
publisher |
American Association for the Advancement of Science (AAAS) |
publishDate |
2024 |
url |
http://dx.doi.org/10.1126/sciadv.adj9546 https://www.science.org/doi/pdf/10.1126/sciadv.adj9546 |
genre |
Ice Sheet |
genre_facet |
Ice Sheet |
op_source |
Science Advances volume 10, issue 23 ISSN 2375-2548 |
op_doi |
https://doi.org/10.1126/sciadv.adj9546 |
container_title |
Science Advances |
container_volume |
10 |
container_issue |
23 |
_version_ |
1802645618460459008 |