This new picture of M54 — a part of a satellite galaxy to the Milky Way called the Sagittarius Dwarf Galaxy — is part of a “test case” astronomers have to figure out a mystery of missing lithium. For decades, astronomers have been aware of a dearth of lithium in our own galaxy, the Milky … Continue reading Elemental Mystery: Lithium Is Also Rare Outside Of The Milky Way