????(é??÷????ó??????ú?????ü???ˇ?????ń?-?é???ú?¨)
?????????ú?????ü???ˇ?í°??¨?????????ń′??§×???°?רˇ????úó???????′?????ěě??????ía???ń°ě?????÷???í???¤S?¤????(Mark S. Hess)
????8??5???????úó?????(NASA)???????????????????×′????????-?????ń′????-???§??
???????????′?ó?????§???ü?????????????a?ü?ń???????????????ň???üě????é???éá?????????á?8??15????NASAˇ?????áí??ě??????¤??á??a?????é???é?????é???????????ü?????-?y???éá??°???°???ń′???????×é??????á????°?????é???a?ú???ń′???
?????a??????á??????×′?????????×?á??????ń′?′??yá?ˇ????ó′ó??????1.3íň?ě???ń′???×°?ú2000????×ó???????ě???ń′?????′ó??15ˇ??ó???-??×?á???????????á???ó??????????°???ü???ě???????ń′?ó?15?ě??ˇ?×°?ú3????×ó????
????×??????a???-?????ń′?????′??ú?í???????ń′?????????????é????í70??′ú??×?????á????ú?ú????°??Y??′???1984??ó????í????′?????1997????ó????§???????÷?é?á????ěě??ě¨?ú°??¨??11?????????ń????×÷ó????ň???ňNASA?÷?????????ń′??????????????ń′????-??????á??????????′?-?ň?????ú?ú???????í??ěě??????1???°???????°????
????óéóú????????????????ó??????ú???ňé???????????????á?????í??ń′??????ň??????í¨?y?yé¨?????ó??á???????í???ˇ??????ň??ě????ú×????ó????í????ó???????ü??′??í????í¨?yí¨??????ˇ??í?????ú?Y????????×÷?é???ó???ň???ň×????????-??????′????ó????′????ó??í??ń??á????í???-?????ń?ˇé??í???????a?????????ńěěˇ′?′???′??????íˇ??ˇ???×ü???????yóú???y???-?ň???Y???????§???-?????ń′??-??ˇ??????ú??′??°′ó?′??????ó??y??é??áó??????í?????????′??éí?y??
?????°???′???a???ˇ?????????ó????????ó?á???×??é?????Y?a?????é????ě????????ú?ú??ěě??ě¨???????????????°??′????ó???yá???′??ó′ó???ú?ˇ×?á??ó???á?×???§???????????????ń?????ú???§???á?????????é????
?????í′ó?ú?í????????í???????????á???ěa??NASA??′?????ěě??????ía???ń°ě?????÷???í???¤S?¤????(Mark S. Hess)?ó?üá??????????°×¨ˇ???×÷??NASA????????????ó??????÷???í????á????a?????é???????í°?????
???????ú?????ü???? ?????°??????NASA???a?????ó′??????????°???-???§???????????°????×???(?′???ó′????????ú??ěě?????ň??????°??Y???????????ú????????)??
?????í???? ???y????????á??????ˇ?¨????ěa???????y?ú′ó?????????é???ü?????????????ń′??é?ü?y?ú?ó?ü?ü??????????ˇ?ěé×????ň?????-??×?????á?????í?????í?????ˇ????a?y???????????ˇ??????ěa???????????ü????????????°?×?á????í?é??′ó???????a?????ń′??????????????í???í?ú?ü??éíé???ˇ?éú?????é??????????????????′?°???
???????ú?????ü???? ???Y???í?????ń′?ó?13000???ě??2000??????′??ó′ó???ó?????ˇó????ü???Y?×?§×??????????a?y?ü?é?ü?????§í??????????°????ě??°??ˇ?°???????????
?????í???? ??????°??¨?????????-??30???????°?????éá??????????ň?úó??????¤×÷???ü???????????-????á??????????-????á????????ü?????a30?????′????ˇ?éúá????′?????????ú???°?¤×÷???é?????????§???????é??
???????????ú?y?ú?¨??ó??a?????ń′?ó????????ü???????′°??ú???????????????????????????????ó????ó?????????????ˇ??????°??á?????ó??ó′??y?a?????ń′??????????????????????????ó′??????ń′????????é?′???°?ú?′í??ó????′??í???????????á?????????????a?????ń′??????????ń????????ía?????????áé??é?????????????ň(é????í70??′ú)′?′????ń′??????ˇ???°??í????y?Y???a???????í?é??í??í???°??????
???????????á???°?a??áí???°′?′??y?a?????ń′????¨??????×??????°é????í60??′ú???′??ó??y?a?????ń′????ú?????a???????í?ü?¨?????ń′?á???í??????????á?í60??′ú?????úó?????ˇ??ń??????á????????ˇ?¨?a???ú????ˇńó?′?′????ń′?????óň???ň′??????????¤×÷á??ü′ó???????ú???????°?°?????÷???????????????×ó???é????ó′??y?a?????ń′??????ü???????úě???á???
???????ú?????ü???? ?a?????ń′???ó???′ó?????????§??????
?????í???? ó????????ü??ó?ě????????????§???????ň?????ń′?????°ü?????÷?????????????-?ú°??¨???????????ň??′?????á??Y??????????á????′??????ó???????′????ú??′??a??????ˇ?????????ó????ü??°?????í???
???????????????????ń′????????á??ˇ??ü???????ó?é?′?ü??????ˇ?éúá????′???é?????????????a?????ń′?é?ˇ???ó??¤??ó?????????ˇ??í?úóú?ü?????ú???????ó?-???????????ń′??????????÷???????§?úóú???§á??????ú?????-?????a?????ń′????ú??????á?°??¨??????????×′????
???????????????????????ú???????ó?-???ü?????¤???ň?????ń???y?ě???ú??????????ˇ????ň?????????????????ň??×?????????????????×????ú???ń′????????í??????×???????×??????a???????í?′?????a???????ú???-??á????????????ü?????a?ú???ń′??????′?????í?é????????????
???????ú?????ü???? °??¨???????????y?ě??ó???ěě?????′?áó????′???????ń′????ü????°ü???????ú?Y?????ń′?ó?í????????′????
?????í???? ??????ó????′???????ń′????ň?????????????????????ě???ń′????ü????15ˇ??ó??????????????′???°ü???ü????????í¨?y?a???????????ňé??ü?ó?ü′ó???ňé?ˇ???????ó???????°ü?¨ó???ˇé′??????y??ó????????????é????????′???˙˙?a?????ń′?é?ó?14????í?????????????ó??????ú???ňé????????é????
???????ń′???ó??′???ˇ???????ú°??¨???′?????ń???y?ě?????¤×÷?????á°??????????????°?????-?y???ě???????′?????????????????′???§??
???????ú?????ü???? ???????°?ˇ??×???×????ü?????a?????ń′??????????a?ú???ń′?×??????????§??ó???ó?????′??????????§ó???′ó??
?????í???? ?????????????¨???¨?ü?????a?????ń′????????ü?????′??°ěˇ¨???á??ó????????é?ü??ˇ?°????á??????
???????????????ü???????ń′????°???-?úá??ü40?????′????′??ú???′???ü?????????????Y?×?????é????????×??????ü?????ü?????????§??ˇ¨??á???
?????′?′?????ú?????ü??????/??????
