星际来客带来早期宇宙的线索
Most comets we discuss belong to the solar system, even when they travel from its cold outer edge. An interstellar comet is different: it arrives from another star's neighborhood and leaves again.
That makes such an object a rare messenger. Its path, chemistry and brightness can hint at the conditions in which it formed, long before it passed near our telescopes.
Inspired by public Scientific American article clues · Rewritten by Vocabsavvy · Vocabsavvy Original (public-snippet inspired)