329E-348-16

A clear night with excellent pinpoint star images allowed me to discover 16 near Earth approaching asteroid candidates with the Catalina Sky Survey 60 inch telescope on Mt Lemmon, Arizona. This 9 hr period of time provides us with a snap shot of the kinds of objects which constantly zip past our home planet. Thirteen of the candidates turned out to fit the definition of an Earth approaching object, two were lost because of a lack of additional observations, and the other one is an inner main belt asteroid which for a time imitated an Earth approaching object The thirteen close approachers travel about the Sun with orbital periods ranging from 3.6 years to only 248 days. The largest is more than a quarter of a mile in diameter while the smallest is about the size of a small U-Haul truck. Most of them stay relatively far from Earth with the closest approacher having the possibility of coming to within three quarters of the Moon's distance from our home planet. One of the more interesting members of the group is 2017 FU90, a 100 foot diameter space rock which makes frequent visits to the vicinities of Mercury, Venus, Our Moon and Earth. It must be made out of pretty tough stuff since it doesn't melt or evaporate when once every 248 days it is closer to the Sun than the planet Mercury. If it is composed largely of iron, nickel, and other metals it could be a target for space mining. Astronomers will need to obtain a spectrum of the patterns of colors sunlight it reflects to get an idea of its chemical composition.