NASA Logo, External Link
Facebook icon, External Link to NASA STI page on Facebook Twitter icon, External Link to NASA STI on Twitter YouTube icon, External Link to NASA STI Channel on YouTube RSS icon, External Link to New NASA STI RSS Feed AddThis share icon
 

Record Details

Record 61 of 10284
Semi-volatiles at Mercury: Sodium (Na) and potassium (K)
Author and Affiliation:
Sprague, A.(Arizona Univ., Tucson, AZ, United States)
Abstract: Several lines of evidence now suggest that Mercury is a planet rich in moderately-volatile elements such as Na and K. Recent mid-infrared spectral observations of Mercury's equatorial and mid-latitude region near 120 degrees mercurian longitude indicate the presence of plagioclase feldspar. Spectra of Mercury's surface exhibit spectral activity similar to labradorite (plagioclase feldspar with NaAlSi3O8: 30-50 percent) and bytownite (NaAlSi3O8: 10-30 percent). These surface studies were stimulated by the relatively large abundance of Na and K observed in Mercury's atmosphere. An enhanced column of K is observed at the longitudes of Caloris Basin and of the antipodal terrain. Extreme heating at these 'hot' longitudes and severe fracturing suffered from the large impact event could lead to enhanced outgassing from surface or subsurface materials. Alternatively, sputtering from a surface enriched in K could be the source of the observed enhancement. Recent microwave measurements of Mercury also give indirect evidence of a mercurian regolith less FeO-rich than the Moon. An anomalously high index of refraction derived from the whole-disk integrated phase curve of Danjon may also be indicative of surface sulfides contributing to a regolith that is moderately volatile-rich. The recent exciting observations of radar-bright spots at high latitudes also indicate that a substance of high volume scattering, like ice, is present in shadowed regions. Other radar-bright spots have been seen at locations of Na enhancements on the atmosphere. All combined, these pieces of evidence point to a planet that is not severely depleted in volatiles or semi-volatiles.
Publication Date: Jan 01, 1994
Document ID:
19950015401
(Acquired Dec 28, 1995)
Accession Number: 95N21818
Subject Category: LUNAR AND PLANETARY EXPLORATION
Coverage: Abstract Only
Document Type: Conference Paper
Publication Information: Lunar and Planetary Inst., Conference on Deep Earth and Planetary Volatiles; p 44
Publisher Information: United States
Financial Sponsor: NASA; United States
Organization Source: Arizona Univ.; Lunar and Planetary Lab.; Tucson, AZ, United States
Description: 1p; In English
Distribution Limits: Unclassified; Publicly available; Unlimited
Rights: No Copyright
NASA Terms: EQUATORIAL REGIONS; FELDSPARS; MERCURY (PLANET); MERCURY ATMOSPHERE; MERCURY SURFACE; POTASSIUM; SODIUM; SPECTRA; STRUCTURAL BASINS; TEMPERATE REGIONS; AUGMENTATION; OUTGASSING; POLAR REGIONS; REFRACTIVITY; REGOLITH; SCATTERING; SURFACE PROPERTIES
Imprint And Other Notes: In Lunar and Planetary Inst., Conference on Deep Earth and Planetary Volatiles p 44 (SEE N95-21777 06-46)
Availability Source: Other Sources
› Back to Top
Find Similar Records
NASA Logo, External Link
NASA Official: Gerald Steeman
Site Curator: STI Program
Last Modified: August 27, 2013
Contact Us