Hygiea is a very large asteroid circling the sun between Mars and Jupiter, inside the main asteroid belt. NASA JPL does not treat Hygiea as potentially hazardous, because its orbit never carries it near Earth.
One lap around the sun takes Hygiea 2,030 days (5.56 years). Over that circuit it swings between 2.79 AU and 3.49 AU from the sun, travelling at an average of 16.83 km/s. At 407.1 kilometers across, Hygiea is roughly the size of the U.S. state of Iowa.
Hygiea has been watched long enough to time its spin: one full turn on its axis takes 13.83 hours.
Its spectral type — C on the Tholen scale, C on SMASSII — suggests Hygiea holds water, iron, nickel, cobalt, nitrogen, and ammonia.
At their nearest, the orbits of Hygiea and Earth stay 1.78 AU apart. That is a comfortable margin, and it holds at every point in the orbit.
Orbital simulations run by NASA JPL's CNEOS turn up no close approaches to Earth.
The orbit of Hygiea is pinned down by sightings going back to May 26, 1849, the most recent officially logged on June 23, 2023. The IAU Minor Planet Center holds 4,463 observations behind that solution.
A ◯ pink circle marks where Hygiea sits. It may fall outside your current field of view — use the controls below to change the position, location and time.