In less than 24 hours, while observing with the Catalina Sky Survey's 60 inch telescope on Mt. Lemmon, Arizona , I discovered two 25 foot diameter space rocks that theoretically can pass less than a quarter of the Moon's distance from us. After I posted my discovery observations on the Minor Planet Center's Near Earth Object Confirmation page one of them received immediate attention, as an incoming object, and was tracked by observers at 14 different observatories around the world. Scientists at the Minor Planet Center used these data to calculate it's 926 day orbital path around the Sun, estimate it's size, and give it the name 2017 TH5. 36 hours after I first spotted 2017 TH5 streaking through the night sky it came to less than 60,000 miles from the surface of our planet traveling at 7.6 miles per second. 8 hours and 49 minutes later it passed less than half a lunar distance from the surface of our moon. If 2017 TH5 would have been on an impact trajectory with Earth humans would have had time to prepare for a spectacular light show. Approximately once every 5 years a tiny asteroid like 2017 TH5 enters our atmosphere exploding at an altitude about 3 times higher than airliners fly releasing the energy of about 5,000 tons of TNT. Asteroid hunters are well on our way towards being able to issue a warning to stay away from doors and windows should a small space rock be discovered to be on an impact trajectory with planet Earth.