Department of Astronomy, University of Maryland, College Park, MD 20742-2421 USA.
Science. 2011 Jun 17;332(6036):1396-400. doi: 10.1126/science.1204054.
Understanding how comets work--what drives their activity--is crucial to the use of comets in studying the early solar system. EPOXI (Extrasolar Planet Observation and Deep Impact Extended Investigation) flew past comet 103P/Hartley 2, one with an unusually small but very active nucleus, taking both images and spectra. Unlike large, relatively inactive nuclei, this nucleus is outgassing primarily because of CO(2), which drags chunks of ice out of the nucleus. It also shows substantial differences in the relative abundance of volatiles from various parts of the nucleus.
了解彗星的工作原理——是什么驱动它们的活动——对于利用彗星研究早期太阳系至关重要。EPOXI（太阳系外行星观测和深度撞击扩展研究）飞掠彗星 103P/Hartley 2，这颗彗星的核异常小但非常活跃，同时获取了图像和光谱。与大型、相对不活跃的核不同，这个核主要是因为 CO(2) 而排气，CO(2) 将冰的碎片从核中拖出。它还显示出核的不同部位挥发物相对丰度的显著差异。
