| タイトル | Caloris Basin - An enhanced source for potassium in Mercury's atmosphere |
| 著者（英） | Hunten, Donald M.; Sprague, Ann L.; Kozlowski, Richard W. H. |
| 著者所属（英） | NASA Ames Research Center|Arizona Univ. |
| 発行日 | 1990-09-07 |
| 言語 | eng |
| 内容記述 | Enhanced abundances of neutral K in the atmosphere of Mercury have been found above the longitude range containing Caloris Basin. Results of a large data set including six elongations of the planet between June 1986 and January 1988 show typical K column abundances of about 5.4 x 10 to the 8th K atmos/sq cm. During the observing period in October 1987, when Caloris Basin was in view, the typical K column was about 2.7 x 10 to the 9th K atoms/sq cm. Another large value was seen over the Caloris antipode in January 1988. This enhancement is consistent with an increased source of K from the well-fractured crust and regolith associated with this large impact basin. The phenomenon is localized because at most solar angles, thermal alkali atoms cannot move more than a few hundred kilometers from their source before being lost to ionization by solar ultraviolet radiation. |
| NASA分類 | LUNAR AND PLANETARY EXPLORATION |
| レポートNO | 90A49945 |
| 権利 | Copyright |
| URI | https://repository.exst.jaxa.jp/dspace/handle/a-is/353807 |
