2026年1月2日
NanoSail-D2
Image Credit & Copyright: Ralf Vandebergh
Explanation: In 2011, on January 20, NASA’s NanoSail-D2 unfurled a very thin and very reflective 10 square meter sail becoming the first solar sail spacecraft in low Earth orbit. Often considered the stuff of science fiction, sailing through space was suggested 400 years ago by astronomer Johannes Kepler, who had observed comet tails blown by the solar wind. But modern solar sail spacecraft designs, like NanoSail-D2, Japan’s interplanetary spacecraft IKAROS, or the Planetary Society’s Lightsail A, rely on the small but continuous pressure from sunlight itself for thrust. Glinting in the sunlight as it circled planet Earth, NanoSail-D2’s solar sail was periodically bright and visible to the eye. These remarkably detailed images were captured by manually tracking the orbiting solar sail spacecraft with a small telescope.
Tomorrow’s picture: moon lighting
纳米帆船-D2
影像提供与版权: Ralf Vandebergh
说明: 2011年1月20日，NASA的NanoSail-D2展开了一块10平方公尺的超薄高反射率太阳帆，成为首个进入近地轨道的太阳帆航天器。在太空中航行常被认为是科幻小说中的情节，但早在400年前，天文学家约翰尼斯·克卜勒他观察到彗星的尾巴被太阳风吹动，就提出了这个想法。然而，现代太阳帆航天器的设计，例如NanoSail-D2、日本的星际探测器IKAROS以及行星协会的Lightsail A，都依赖太阳光本身产生的微小但持续的压力作为推进力。NanoSail-D2的太阳帆在绕地球运行时，于阳光下闪闪发光，周期性地变得明且肉眼可见。这些细致入微的影像是透过小型望远镜手动追踪这一轨道运行的太阳帆太空船所拍摄的。
明日的图片: moon lighting
