Journal article
Evidence for ultra-cold traps and surface water ice in the lunar south polar crater Amundsen
- Abstract:
-
The northern floor and wall of Amundsen crater, near the lunar south pole, is a permanently shaded region (PSR). Previous study of this area using data from the Lunar Orbiter Laser Altimeter (LOLA), Diviner and LAMP instruments aboard Lunar Reconnaissance Orbiter (LRO) shows a spatial correlation between brighter 1064 nm albedo, annual maximum surface temperatures low enough to enable persistence of surface water ice (<110 K), and anomalous ultraviolet radiation. We present results using data from Diviner that quantify the differential emissivities observed in the far-IR (near the Planck peak for PSR-relevant temperatures) between the PSR and a nearby non-PSR target in Amundsen Crater.
We find features in far-IR emissivity (50–400 μm) could be attributed to either, or a combination, of two effects (i) differential regolith emissive behavior between permanently-shadowed temperature regimes and those of normally illuminated polar terrain, perhaps related to presence of water frost (as indicated in other studies), or (ii) high degrees of anisothermality within observation fields of view caused by doubly-shaded areas within the PSR target that are colder than observed brightness temperatures.
The implications in both cases are compelling: The far-IR emissivity curve of lunar cold traps may provide a metric for the abundance of “micro” cold traps that are ultra-cool, i.e. shadowed also from secondary and higher order radiation (absorption and re-radiation or scattering by surrounding terrain), or for emissive properties consistent with the presence of surface water ice.
- Publication status:
- Published
- Peer review status:
- Peer reviewed
Actions
Access Document
- Files:
-
-
(Preview, Accepted manuscript, pdf, 5.6MB, Terms of use)
-
- Publisher copy:
- 10.1016/j.icarus.2019.06.002
Authors
- Publisher:
- Elsevier
- Journal:
- Icarus More from this journal
- Volume:
- 332
- Pages:
- 1-13
- Publication date:
- 2019-06-07
- Acceptance date:
- 2019-06-03
- DOI:
- EISSN:
-
1090-2643
- ISSN:
-
0019-1035
- Language:
-
English
- Keywords:
- Pubs id:
-
pubs:1033623
- UUID:
-
uuid:515769db-8621-47bd-8082-d1cd8728891e
- Local pid:
-
pubs:1033623
- Source identifiers:
-
1033623
- Deposit date:
-
2019-09-14
Terms of use
- Copyright holder:
- Elsevier Inc.
- Copyright date:
- 2019
- Rights statement:
- © 2019 Elsevier Inc. All rights reserved.
- Notes:
- This is the accepted manuscript version of the article. The final version is available online from Elsevier at: https://doi.org/10.1016/j.icarus.2019.06.002
If you are the owner of this record, you can report an update to it here: Report update to this record