• Scary news: Asteroid may pass Earth by just 6,880km in October • The Register

    NASA’s preparing another round asteroid defence tests, thanks to the October fly-by of a rock that may come within a cosmic whisker of the Earth.

    Asteroid #2012TC4 is said rock and is between ten and thirty metres across. NASA says it is “certain it will come no closer than 4,200 miles (6,800 kilometers) from the surface of Earth.” That’s a very close encounter indeed given the term “nearby” is applied to rocks that get anywhere inside lunar orbit.

    We don’t know a lot about 2012 TC4 because when it was spotted by the Pan-STARRS 1 telescopes in Hawaii we only got a look at it for seven days.

    That’s not a bad thing for a dry-run asteroid-spotting campaign, something proposed by University of Arizona astronomer Vishnu Reddy.

    As Reddy explains in the University’s announcement, what’s on the table is “an observational campaign to exercise the network and test how ready we are for a potential impact by a hazardous asteroid”.