One lunar day is equivalent to four weeks on Earth, made up of two weeks of continual sunshine and two weeks of darkness. That makes relying on solar power very challenging.
Scroll to load interactive demo
，详情可参考WPS下载最新地址
The BBC spoke with spectators who walked alongside the monks for the last leg of their trek, from Capitol Hill to the Lincoln Memorial.
If you don't have access to binoculars or a telescope you might be able to attend a local astronomy society event to get a better look.
The upheaval comes as NASA has struggled to fuel the massive Space Launch System rocket for the upcoming Artemis II lunar mission, and Isaacman has sought to revitalize an agency that has moved at a glacial pace on its deep space programs. There is ever-increasing concern that, absent a shake-up, China's rising space program will land humans on the Moon before NASA can return there this decade with Artemis.