Modern astrological symbol for asteroid 10 Hygiea (U+2BDA ⯚). Two serpents coiled around a rod (a caduceus: Hermes' staff), which is the symbol of Hermes/Mercury, not of Hygieia. This is a symbol commonly used in astrology software (e.g. Astrolog, SolarFire), originally as a mistake for Asclepius' rod.
Astronomicon font, shareware under the SIL's Open Font License.
Roberto Corona