Space is probably busier than you think. Little chunks of rock are randomly flying through the solar system all the time. Most are relatively small, extremely dark and tough to find.
We don’t see most asteroids until they’re very close, often a few days or even hours before passage.
Asteroids are found mostly through sky surveys. These are computer controlled telescopes which look for movement within the field of stars. It’s the kind of mind numbing work best left to computers.
Based on a note the dinosaurs left behind, we are fearful of asteroids. Reasonable fear.
Asteroid 2015 TB145 will pass near Earth on Saturday (Halloween), three weeks after it was discovered. Around a quarter mile in diameter, it will be a little farther from us than the Moon at 300,000 miles.
That’s a safe distance.
It will be best viewed by a team from NASA’s Jet Propulsion Lab in Pasadena. They’ll be bombarding it with radar, looking for a 2-meter resolution 3D image.