I promised that Eos should get an own article, so here it is. Eos is asteroid #221, was discovered in 1882 and can be found in the Outer Main Belt. Eos moves in five years and 81 days around the Sun. The orbit of Eos exhibits an inclination with respect to the ecliptic of 10.9°. Eos is the head of a Hirayama-family. I referred to Hirayama-families already sometimes as asteroid families. Hirayama-family is actually a subcategory of asteroid family and a more precise technical term because Hirayama-families are defined as asteroids with similar orbits, while asteroid families may have just something in common. They are only recently thought to be chunks of a parental asteroid. The Japanese astronomer Hirayama Kiyotsugu (平山 清次), who lived from 1874 until 1943, identified in 1918 the asteroid families of Themis, Eos, and Koronis. Hirayama Kiyotsugu (平山 清次) described also the asteroid families of Maria, Phocaea, Flora, and Pallas during the 1920s. To honor this astronomer was asteroid #1999 or 1973 DR, a Main Belt Asteroid, named Hirayama. It seems to be neither peculiar nor part of a Hirayama-family. The Eos-family is defined by semi-major axes of the orbits between 2.95 and 3.1 Astronomical Units, and inclinations of the orbits between 8° and 12° with respect to the ecliptic, and staying on Jupiter’s side of the Kirkwood-gap, which is defined by the 7:3 orbital resonance with Jupiter. Eos is of the spectral type S, this means rich in silicates and typical for the Inner Main Belt, although Eos is a part of the Outer Main Belt, where it is less usual, but not unusual.

Eos means dawn, so Eos has at least two variants, which are represented by asteroids too. This is the asteroid Dawn or #1618 or 1948 NF, a Main Belt Asteroid and member of the Koronis-family. The orbital elements of Dawn are almost identical with those of Nansmith or #13765, but even less is known about that unspectacular asteroid. The other is A912 TC (an older designation) or #94 or Aurora because Aurora is named after the Roman goddess of Dawn, who is only a copy of the Greek Eos. #94 is a large asteroid in the Outer Main Belt. There seems to be nothing peculiar to Aurora, except her large size.

Eos belongs to the titan goddesses. She is a daughter of Hyperion and Theia. Eos is the sister of Helios and Selene. For this reason is Aurora the sister of Sol and Luna. Eos has many epithets, most of them describe her beauty. The epithet Erigeneia describes that she wakes up early, and the epithet Pallantis describes that she belongs to Pallas somehow, possibly as the daughter of Pallas, who would then most likely be the titan god Pallas. Eos precedes every morning her brother Helios moving across the sky in her own cart. It is drawn by two horses, that are named Phaethon (“shimmering”) and Lampos (“bright”). Most interesting is a poem from Sappho, which is only existent as a fragment and describing that Aphrodite was jealous of the beauty of Eos. So Aphrodite cursed Eos, so that Eos was always longing for mortal men. This made Eos get much offspring with many half-gods among it. Eos has together with her first husband, the titan god Astraios, the sons Eosphoros, Notos, Euros, Boreas, and Zephyr. Notos is the wind from the south. Euros is the wind from the east. Boreas is the wind from the north. Zephyr is the wind from the west. These four winds are together known as the Anemoi.

The asteroid #3200 or 1983 TB or Phaethon shall be named after Phaëton, the son of Helios, but the name of the asteroid resembles much more the name of one of Eos’ horses! Then it would still be a name, that is good for an asteroid, that also crosses the orbits of Venus and Mercury, although it is categorized as an Apollo-asteroid.

Asteroid #12923, that was discovered in 1999, is named after Zephyr. This asteroid belongs to the Apollo-group. Asteroid #1916 or 1953 RA is named after Boreas. This is an Amor-asteroid. Nothing else seems to be peculiar about these asteroids. Zephyr has some significance in mythology because he brought the spring. Boreas brought the winter and was also involved in a tale, where he abducted a princess.

Eos’ best known affair and then also husband is Tithonos, who was a prince and a son of Troy’s first king Laomedon. Because he was her husband, so Eos asked immortality for him from Zeus, but Zeus didn’t like the idea, so granted immortality to Tithonos, but let him continue to age. Eos hadn’t asked eternal youth for Tithonos explicitly because it seemed to be self-explaining. There are no reports of similar incidents, hence it was very likely self-explaining and Zeus only expressing anger this way. So Tithonos aged, he shrinked, and his voice became strident. Out of pity had finally either Eos or Zeus turned into a cicade, that always accompanied Eos. Cleitus was another prince, with whom Eos fell in love. He was made immortal after his death. There seems to have occured a change in mythology because often even Zeus can’t help if somebody already died, but in other cases immortality is granted only after death. The latter is probably a later development in the mythology.

Eos let’s us choose from a broad scope of possible meanings for astrology. Particularly because there are also the asteroids Dawn and Aurora as alternatives. So what is most characteristic for Eos? I would say it is the recklessness and naïvety of the youth. Asteroid Eos could show you a point in your natal chart, where you should spend more attention in order to avoid getting fooled.