Nasa's Sun skimming mission 美国国家航空航天局启动太阳探测计划_BBC

Nasa's Sun skimming mission 美国国家航空航天局启动太阳探测计划

美国国家航空航天局（Nasa）计划于2018年向太阳发射一个太空探测器，这艘探测器飞船将穿过1400摄氏度的高温地带，最终冲入距太阳表面400万英里（约640万公里）的区域。这个探测器将成为有史以来离太阳表面最近的人造物体。该太阳探测计划以天文物理学家尤金·派克（Eugene Parker）的名字被重新命名，这位科学家曾引领与太阳“大气层”带电粒子流现象“太阳风”有关的研究。请听报道。

To understand the daring nature of this mission, bear in mind a few key numbers: Earth orbits the Sun at a distance of 91 million miles; Mercury is much closer at about 21 million. But the Nasa Solar Probe will get to within four million miles.

This is uncharted and extremely hostile territory. The spacecraft will have to endure a temperature of nearly 1400C - the kind of heat generated inside a blast furnace in a steelworks. So the craft has special protection – a shield of carbon-composite about 4.5 inches thick. But the slightest error in its flight and the instruments sheltering behind the shield will be fried.

The motivation for flying so close to the Sun is to explain some of the mysteries about it. Why, for example, the greatest heat is not at the surface, but in the corona, a region surrounding the Sun? It’s here that vast flares are generated that can send streams of particles our way, which can disrupt anything electronic including satellites or power grids. Understanding this so-called space weather is seen as vitally important to our modern economies, and getting very close is the best way to do that.