星际彗星揭示太阳系并非宇宙常态
In recent years, astronomers have detected a handful of objects that entered our solar system from interstellar space. The first was the oddly shaped 'Oumuamua in 2017. More recently, a comet from beyond our sun's influence was spotted as it neared the sun. These wanderers are extremely faint and move rapidly, making them hard to find. But when caught, they offer a rare glimpse of matter from distant stars.
When scientists studied the light from this interstellar comet, they focused on its chemical composition. They measured the ratio of deuterium, a heavier form of hydrogen, to normal hydrogen. In space, deuterium forms more readily at very low temperatures. The comet's deuterium level turned out to be far higher than in any comet from our own solar system. This suggests that it was born in a region much colder than our solar system's edges, perhaps near the frigid core of a distant cloud.
Inspired by Scientific American reporting · Rewritten by Vocabsavvy · Vocabsavvy Original (inspired-by attribution)