经济学人丨空间尘埃可损毁卫星丨2017.09.30丨总第1007期

HOW is a speck of dust like an atom bomb? It sounds like a child’s riddle. But the answer may explain the fate of many satellites that have failed prematurely in orbit over the years. For the riddle to work, the speck must be travelling at 70km a second, or thereabouts. If it is, the riddle’s solution is that both can generate an electromagnetic pulse capable of knocking out unprotected electronic equipment.

一粒尘埃怎么可能像原子弹那么厉害呢？听起来像是个孩童的谜题。不过其谜底或许可以解释长久以来，许多卫星在轨道中运行时过早报废的原因。要使这一谜面成立，尘埃粒子的速度必须到达70km/s左右。如果真是这样，这一谜题的解释即为，两者均能产生能够毁坏未受保护的电子设备的电磁脉冲。

• Speck：n.　灰尘；尘埃；小颗粒

• Riddle：n.　谜语

That, at least, is the hypothesis now being investigated by Sigrid Close of Stanford University. Dr Close came up with it in 2010, when she was shooting small particles at various types of spacecraft material placed inside a vacuum chamber at the Max Planck Institute in Heidelberg, Germany. These experiments suggested that when a micrometeoroid, to give such dust its technical name, collides with a satellite, it will not just do a small amount of mechanical damage. If travelling fast enough, it will also create a shock wave that vaporises part of the spacecraft’s metallic skin.

这，至少已成为斯坦福大学的西格丽德·克洛斯正进行研究的假说。克洛斯博士于2010年提出这个假设，当时她正在德国海森堡马普研究所进行着在真空条件下，用粒子轰击各种种类航天器材料的实验。这些实验的结果表明，当微流星体（该尘埃被给予的专业名称）撞击卫星时，不仅会造成轻度的机械损伤，如果撞击速度足够快，还会产生足以气化飞行器金属外壳的冲击波。

• Micrometeoroid：n.　[天]微流星体

• Vaporises：n.　汽化