Asteroid Nysa's rare three-lobed structure challenges formation models

Named for the mythical valley where the god Dionysus was raised in secret by nymphs, the asteroid 44 Nysa inhabits the asteroid belt between Mars and Jupiter. Through observations by the Hubble Space Telescope, astronomers have determined it to be the largest and brightest known member of a rare category of asteroids called "E-types," made of unusually bright, enstatite-rich material similar to some rare meteorites found on Earth. Separately, models built from how its brightness flickers as it spins hinted it might have an elongated, lopsided shape, often seen in large asteroid pairs.