ASTEROID IMPACT UNLIKELY UNTIL 2880

Earthlings can breathe a little easier for the next 800 years

- Elizabeth Howell

A fresh assessment of a distant risky asteroid brings good news: it's even less of a threat than astronomers had feared. The chances of an asteroid dubbed 1950 DA crashing into Earth were always tiny and long in the future. As of 2015, scientists had calculated that the object had a 1-in8,000 chance of impacting Earth in the year 2880. But a new analysis knocks the asteroid out of the top spot of NASA's list of known asteroids that are potentially hazardous to Earth. "1950 DA shouldn't be of any concern," said Davide Farnocchia, a navigation engineer at NASA's Jet Propulsion Laboratory (JPL) in California. "I'd say that it's encouraging that we can identify the remote possibility of an impact for this object more than 800 years in advance."

The space rock is 1.3 kilometres (0.8 miles) wide, and scientists have a pretty good idea of its shape thanks to observations by the now-defunct Arecibo Observatory in Puerto Rico. Modelling previously suggested that the asteroid is more rubble than rock, which would defuse any possible impact. Fortunately, the new assessment says the asteroid poses even less risk than previously believed. "The probability of impact is tiny - 1 in 30,000," Farnocchia wrote of the asteroid, a substantial improvement from the previous odds. "But even in the very unlikely case that 1950 DA were on an impact trajectory, the possible impact is in 2880, and that provides plenty of time for mitigation," he added.