Free Republic

Astronomer Brian G. Marsden, a comet and asteroid tracker who stood sentinel to protect the Earth from collisions with interplanetary rocks and other remnants of the solar system's creation, died Thursday of cancer at Lahey Clinic Medical Center in Burlington, Mass. He was 73. Director emeritus of the Minor Planet Center at the Harvard-Smithsonian Center for Astrophysics in Cambridge, Mass., Marsden was perhaps best known for his 1998 announcement that an asteroid known as 1997 XF11 might strike the Earth in 2028, causing untold damage. The announcement sparked additional studies which quickly showed that such an impact was unlikely. Marsden,...

Astronomers have been so horrified by press scares over asteroids that they are toning down the scale they use to rate the threat posed in an attempt to discourage journalists from covering potential collisions. The most prominent recent furore involved asteroid QQ47, which briefly had a one-in-a-million chance of crashing into our planet in 2014. Some astronomers even want the way asteroids are assessed to be completely overhauled. The Torino scale, developed in 1999 by Rick Binzel of the Massachusetts Institute of Technology, is used to inform the public about potential impacts. It rates an asteroid's threat on a scale...