221 Eos is a K class (more about this in a minute) main belt asteroid discovered by Johann Palisa on January 18th 1882. It’s about 100 km wide, weighs in at a healthy six million trillion tonnes (give or take a few hundred thousand) and is quite dim at magnitude 7.67.
Eos lends its name to an extensive family of asteroids, all sharing roughly similar orbits, and all thought to have originated from an almighty collision some time in the distant past, which the latest best guesses put at around a billion years ago. About 300 members of the family are known, all being similar to S-types, but not identical, so they get their own category, the aforementioned K-type.
Eos was named after the Greek goddess of the dawn, shown above in her winged chariot.
Also today, asteroid 468 Lina, a member of the Themis family, was discovered today in 1901 by Max Wolf and named after the family housemaid. It’s probably best if I don’t speculate as to why that might be.