The near-Earth object was thought to pose a slight risk of impacting Earth in 2068, but now radar observations have ruled that out.

After its discovery in 2004, asteroid 99942 Apophis had been identified as one of the most hazardous asteroids that could impact Earth. But that impact assessment changed as astronomers tracked Apophis and its orbit became better determined.

Now, the results from a new radar observation campaign combined with precise orbit analysis have helped astronomers conclude that there is no risk of Apophis impacting our planet for at least a century.

Estimated to be about 1,100 feet (340 meters) across, Apophis quickly gained notoriety as an asteroid that could pose a serious threat to Earth when astronomers predicted that it would come uncomfortably close in 2029. Thanks to additional observations of the near-Earth object (NEO), the risk of an impact in 2029 was later ruled out, as was the potential impact risk posed by another close approach in 2036. Until this month, however, a small chance of impact in 2068 still remained.

When Apophis made a distant flyby of Earth around March 5, astronomers took the opportunity to use powerful radar observations to refine the estimate of its orbit around the Sun with extreme precision, enabling them to confidently rule out any impact risk in 2068 and long after.

Credit: NASA