An anonymous reader shares a CNET report: The problem with asteroids passing near Earth is that they're often difficult to spot. Fortunately the hardest ones to see in our neighborhood also tend to be the smaller ones. Such is the case with 2017 BH30, which was discovered Sunday by the Catalina Sky Survey just hours before passing by us at the creepy-close distance of only 40,563 miles (65,280 kilometres). This asteroid is estimated to be between 15-32.8 feet (4.6-10 metres) in length, making it somewhere between the size of a truck and a... big truck. That's pretty small by asteroid standards, but it's also the closest spotted asteroid to pass us since September when asteroid 2016 RB1 passed within 24,000 miles (about 39,000 kilometres) of our planet's surface, putting it almost as close as satellites in geosynchronous orbit. This is the third asteroid to buzz by earth closer than the distance to the moon this year. We don't expect a closer pass by one of these visitors until October, when asteroid 2012 TC4 could come more than twice as close.