SYDNEY, Australia (Reuters) - Even for an alien it was a poor shot -- an intergalactic out-of-bounds in the water, irretrievably embedded in the earth, for a one stroke penalty.

The mysterious object which slammed into an Australian dam, leaving a large crater and attracting nationwide attention, has turned out to be a meteorite -- but only the size of a golf ball.

Police divers on Friday recovered sediment and fragments from the dam at Guyra, 400 km (250 miles) north of Sydney, which geologists believe came from a ``golf-ball'' size meteorite which landed sometime between Monday and Wednesday.

Despite its small size, the force of the impact left a 15-meter (50 ft) long and 6-meter (20 ft) wide crater in the dam and the meteorite penetrated the bottom of the dam.