When I started writing about astronomy 35 years ago, astronomers knew of just a few thousand asteroids. Now they know and have cataloged half a million asteroids! That’s one reason we hear so often nowadays about asteroids passing near Earth, like the one that will pass on Friday, February 15, 2013. This video is an awesome depiction of the increasingly fast discovery rate for asteroids, over the past three decades. Scott Manley, formerly of Armagh Observatory, created it.
Or, try another graphical representation, also on Armagh Observatory’s website. These are are maps of the inner solar system for the years 1800, 1850, 1900, 1950, 1990, 2000 and 2007 showing the increasing rate of discovery of asteroids.
Also see these links:
Bottom line: Video from astronomer Scott Manley shows the increasingly fast rate of discovery of asteroids in our solar system, and hence of asteroids whose orbits cross that of Earth.
Deborah Byrd created the EarthSky radio series in 1991 and founded EarthSky.org in 1994. Today, she serves as Editor-in-Chief of this website. She has won a galaxy of awards from the broadcasting and science communities, including having an asteroid named 3505 Byrd in her honor. A science communicator and educator since 1976, Byrd believes in science as a force for good in the world and a vital tool for the 21st century. "Being an EarthSky editor is like hosting a big global party for cool nature-lovers," she says.