The temperature difference is not subtle. One side of the Milky Way’s outer halo runs noticeably hotter than the other, a mismatch that has puzzled astronomers since it was measured. That imbalance ...

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Just in time for Valentine's Day, space offers a heart-shaped greeting. The star Mira A, about 300 light-years from Earth, has released material into an expanding cloud of gas and dust resembling a ...