The Catalina Sky Survey Team (CSS) reached an important milestone, and also discovered two highly unusual asteroids in the last few months. The milestone was that CSS discovered its 5000th Near-Earth Object (NEO). On March 31, CSS Astronomer Jess Johnson discovered NEO 2014 FS52 using the 60" reflector on Mt. Lemmon. According to CSS PI Eric Christensen, "This is a fairly ordinary NEO, but an extraordinary statistic! Given that the overall NEO tally stands at 10,758, that means that CSS is responsible for 47% of all NEO discoveries, period." Coupled with the 813 discoveries by the Spacewatch program, that means that LPL astronomers have discovered more than half of all known NEOs.
While 2014 FS52 may have been “fairly ordinary,” two other CSS discoveries were anything but that.
In March, Senior Staff Scientist Steve Larson forwarded news that Catalina Sky Survey observer Rik Hill (Research Specialist, Senior) discovered the "crumbling" asteroid P/2013 R3. Hubble Space Telescope provided the likely first known observation of an asteroid breaking up through spin-up by the YORP effect: http://www.spacetelescope.org/news/heic1405/
And on New Year’s Eve, observer Rich Kowalski discovered an asteroid that impacted Earth the next day. 2014 AA represented only the second time in human history that an object first observed with a telescope hit the Earth. The other, 2008 TC3, was also discovered by Rich, also at CSS. Incidentally, 2014 AA broke up harmlessly over the Atlantic: http://azstarnet.com/news/local/tucson-astronomer-spots-asteroid-before-it-hits-earth/article_82e97cd0-9b2f-5747-95ef-bb5cbb835c6b.html