Metallic messengers from the cosmos: Rare (Al,Cu)-bearing meteorites from the Project Stardust collection

We report the discovery of (Al,Cu)-bearing metallic alloys in two micrometeorites found in the Project Stardust collection gathered from urban rooftop environments in Norway. Most of the alloys are the same as those found in the Khatyrka meteorite and other micrometeorites, though one has a composition that has not been reported previously. Oxygen isotope ratio measurements using secondary ion mass spectrometry show that the Project Stardust samples reported here, like all earlier examples of natural (Al,Cu)-bearing alloys, contain material of chondritic affinity.