Metis

Metis is an S-type asteroid with a diameter of 173 km, orbiting at 2.39 AU in the asteroid belt. It is composed of silicates and metallic nickel-iron, and may be the exposed core remnant of a larger asteroid that was destroyed by a catastrophic collision early in the solar system's history. Metis has a moderately dark surface (albedo 0.18) and shows spectral similarities with asteroid 113 Amalthea, suggesting they may be remnants of the same ancient parent body — fragments of an old dynamical family. Metis contains under 0.5% of the asteroid belt's total mass and has a relatively fast rotation period of just over 5 hours.

Metis can reach magnitude 6.3 at the most favorable oppositions, making it one of the brighter asteroids and visible in binoculars. More typically it shines between magnitude 7 and 9. Its inner-belt orbit means it moves at a moderate pace against the star background. Track its nightly motion over two to three nights using a finder chart to confirm its identity. Metis passes through the zodiacal constellations and is best viewed around opposition months, typically March through May. A go-to telescope makes locating it straightforward, though it is bright enough for manual star-hopping.

Metis was discovered on April 25, 1848 by Irish astronomer Andrew Graham at Markree Observatory in County Sligo, Ireland — the only asteroid ever discovered from Irish soil. It was the ninth asteroid discovered and was named after Metis, the Titaness of wisdom and cunning in Greek mythology, who was the first wife of Zeus. Markree Observatory was one of the most well-equipped private observatories of the 19th century. No spacecraft has visited Metis, and most of what we know comes from ground-based photometry and spectroscopy.