Forecasts of giant asteroids slamming into Earth have been making headlines lately. But how likely is that, really? In the case of one mile-wide space rock recently reported to be on a collision course with our planet, apparently not at all. Subsequent observations of asteroid 2002 NT7, which was said to have a shot at impact on February 1, 2019, have ruled out that possibility.

MIT astronomers discovered 2002 NT7 earlier this month. Initial observations led to estimates of a one-in-250,000 chance of impact in 2019 and another remote chance of collision on February 1, 2060. Since then, however, additional data have provided a clearer picture of the asteroid¿s orbit and reduced uncertainties about its future position. As a result, scientists at NASA¿s Jet Propulsion Laboratory have crossed the 2019 crash off their "impact risk" list.

The new work does not render the 2060 collision scenario totally obsolete though¿not yet anyway. "While we cannot yet completely rule out an impact possibility on February 1, 2060, " the lab states, "it seems very likely that this possibility will be soon ruled out as well as additional positional observations are processed."