Dark matter is believed to be part of the missing mass.

暗物质也被认为是遗失质量的一部分。

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Astronomers have long speculated that the missing baryonic mass might eventually be discovered in intergalactic space or as some large population of galaxies that are difficult to detect.

天文学家长期以来都在推测，最终可能会在星际空间或者是在难以探测的大量星系中发现丢失的重子质量。

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These galaxies may constitute an answer to the long-standing puzzle of the missing baryonic mass in the universe.

这些星系可能为宇宙中长期存在的缺少重子质量这一谜题提供了答案。

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Tony Blair and Alastair Campbell's legal war over the sexed-up Iraq dossier and those missing weapons of mass destruction felled both the DG and the Chairman.

BBC: The BBC has faced worse crises

The leading theory to explain the missing neutrinos was that neutrinos had a little mass, which it turns out would allow them to transform themselves as they traveled from one neutrino type to another.

NPR: Neutrinos: A Cursed Subatomic Particle?

For a few months in 2010 it looked as though the Tevatron might get a reprieve in order to find the last (and heaviest) missing bit of the model the Higgs boson, which is thought to give other particles their mass.

ECONOMIST: The future of physics (1)