Discovered by James Craig Watson in 1873, 132 Aethra is a light-coloured metallic main belt asteroid. It has a rather eccentric orbit that sometimes brings it closer to the Sun than the planet Mars. It was the first such Mars-crosser asteroid to be identified.

The varying light curve of the asteroid implies an elongated or irregular shape for its body.

It is named after Aethra, the mother of Theseus in Greek mythology.