Cook County, Illinois, USA

Fell 2003 March 26, approx. 23:50 hrs

Ordinary chondrite (L5)

A bright fireball was seen by numerous observers in parts of

Illinois, Indiana, Wisconsin and Ohio around midnight of March 26,

2003. Numerous stones fell, mostly concentrated in the area of the

village of Park Forest. At least two houses in Park Forest were

struck, as was the Fire Station. Dozens of other stones or fragments

of stones were recovered in the area in the hours and days following

the fall. Total mass recovered is more than 18 kg, largest stone ~ 3

kg in possession of finder. Description and classification (S. Simon,

UChi; M. Wadwha, FMNH; P. Sipiera, PSF): Most stones are partly to

fully fusion crusted. Some broken faces show brecciated texture,

angular clasts. Cross-cutting dark veins and dark pockets may be of

impact melt origin. No visible chondrules in hand sample. Abundant

troilite and metal visible in some broken faces. Chondrules and

maskelynite are visible in thin section. Classified as an L5

chondrite: mean olivine composition Fa24.7, mean low-Ca pyroxene

Fs20.7Wo1.6. Shock stage S5.